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  4. Event on Scrolling to the end in flowlayoutpanel

Event on Scrolling to the end in flowlayoutpanel

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  • L Luc Pattyn

    private int previousValue;

    public void someEventHandler(...) {
    int currentValue=...;
    if (currentValue==extremeValue && currentValue!=previousValue) doWhatEver();
    previousValue=currentValue;
    }

    :)

    Luc Pattyn [My Articles] Nil Volentibus Arduum

    A Offline
    A Offline
    Ammar_Ahmad
    wrote on last edited by
    #12

    isn't previousValue a readonly value?

    L 1 Reply Last reply
    0
    • A Ammar_Ahmad

      isn't previousValue a readonly value?

      L Offline
      L Offline
      Luc Pattyn
      wrote on last edited by
      #13

      did I declare it read-only? :confused:

      Luc Pattyn [My Articles] Nil Volentibus Arduum

      A 1 Reply Last reply
      0
      • L Luc Pattyn

        did I declare it read-only? :confused:

        Luc Pattyn [My Articles] Nil Volentibus Arduum

        A Offline
        A Offline
        Ammar_Ahmad
        wrote on last edited by
        #14

        Seems like I misunderstood the algorithm.

        1 Reply Last reply
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        • A Ammar_Ahmad

          Thanks for the example. but I still can't figure out how I can use this to know if the user has scrolled to the end.

          N Offline
          N Offline
          Nick Otten
          wrote on last edited by
          #15

          hmm, oke im not really sure why you want to show that messagebox. but I thrown in some more trail and error and i came up with the code below. Note that I ran a little low on time so its a bit of a mess...i recommend throwing in a breakpoint to figure out exactly how the code works before putting it into your project. to test it again make a form (called form1) and add a listbox (txtscroll) in it. then copy paste the code into your form.

          Imports System.Runtime.InteropServices

          Public Class Form1
          Dim WithEvents scrollhandler As MyListener 'class that will watch windows to see if your scrolling
          Private scrolled As Boolean = False 'boolean you can use to flip if a message box was displayed or not...(so it wont loop the messagebox.show)
          Private maxscroll As Int64 'int used to store the max value of the scrollbar
          'dll used to get the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
          _
          Public Shared Function GetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer) As Integer
          End Function

          'dll used to set the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
          \_
          Private Shared Function SetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer, ByVal nPos As Integer, ByVal bRedraw As Boolean) As Integer
          End Function
          
          Private Const SB\_HORZ As Integer = &H0
          Private Const SB\_VERT As Integer = &H1
          
          
          Public Property HScrollPos() As Integer 'property to set or get the horisontal scrollbar value
              Get
                  Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ) 'change txtscroll to the control you use. dont forget the .handle
              End Get
              Set(ByVal value As Integer)
                  SetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ, value, True) 'change txtscroll to the control you use. dont forget the .handle
              End Set
          End Property
          
          
          Public Property VScrollPos() As Integer 'Property to set or get the Vertical scrollbar value
              Get
                  Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_VERT) 'change txtscroll to the control you use. dont forget the .handle
              End Get
              Set(ByVal value As Integer)
                  SetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_VERT, value, True) 'change txtscroll to the control you use. dont forget the .handle
              End Set
          
          A 1 Reply Last reply
          0
          • N Nick Otten

            hmm, oke im not really sure why you want to show that messagebox. but I thrown in some more trail and error and i came up with the code below. Note that I ran a little low on time so its a bit of a mess...i recommend throwing in a breakpoint to figure out exactly how the code works before putting it into your project. to test it again make a form (called form1) and add a listbox (txtscroll) in it. then copy paste the code into your form.

            Imports System.Runtime.InteropServices

            Public Class Form1
            Dim WithEvents scrollhandler As MyListener 'class that will watch windows to see if your scrolling
            Private scrolled As Boolean = False 'boolean you can use to flip if a message box was displayed or not...(so it wont loop the messagebox.show)
            Private maxscroll As Int64 'int used to store the max value of the scrollbar
            'dll used to get the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
            _
            Public Shared Function GetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer) As Integer
            End Function

            'dll used to set the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
            \_
            Private Shared Function SetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer, ByVal nPos As Integer, ByVal bRedraw As Boolean) As Integer
            End Function
            
            Private Const SB\_HORZ As Integer = &H0
            Private Const SB\_VERT As Integer = &H1
            
            
            Public Property HScrollPos() As Integer 'property to set or get the horisontal scrollbar value
                Get
                    Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ) 'change txtscroll to the control you use. dont forget the .handle
                End Get
                Set(ByVal value As Integer)
                    SetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ, value, True) 'change txtscroll to the control you use. dont forget the .handle
                End Set
            End Property
            
            
            Public Property VScrollPos() As Integer 'Property to set or get the Vertical scrollbar value
                Get
                    Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_VERT) 'change txtscroll to the control you use. dont forget the .handle
                End Get
                Set(ByVal value As Integer)
                    SetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_VERT, value, True) 'change txtscroll to the control you use. dont forget the .handle
                End Set
            
            A Offline
            A Offline
            Ammar_Ahmad
            wrote on last edited by
            #16

            Did you test the code...? Well... Because the above didn't work for me. I made a test project to see how it works. but it didn't show me any message...

            N 1 Reply Last reply
            0
            • A Ammar_Ahmad

              Did you test the code...? Well... Because the above didn't work for me. I made a test project to see how it works. but it didn't show me any message...

              N Offline
              N Offline
              Nick Otten
              wrote on last edited by
              #17

              Did you recalculate the max value of your scrollbar? if your listbox is of a differed size then mine (witch it probably is) you have to recalculate it. just run the program. dont scroll and see how many items fit into the listbox (for me that where 18). you want to do the index - [the number you found]. after that it should work.

              maxscroll = index - 18 'calculate max value. everytime you add a item you have to do this again. to calculate this its a bit of a trail and error thing depending on your control

              A 1 Reply Last reply
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              • N Nick Otten

                Did you recalculate the max value of your scrollbar? if your listbox is of a differed size then mine (witch it probably is) you have to recalculate it. just run the program. dont scroll and see how many items fit into the listbox (for me that where 18). you want to do the index - [the number you found]. after that it should work.

                maxscroll = index - 18 'calculate max value. everytime you add a item you have to do this again. to calculate this its a bit of a trail and error thing depending on your control

                A Offline
                A Offline
                Ammar_Ahmad
                wrote on last edited by
                #18

                Oh that kinda worked... but how am I ganna calculate the value in a control like this one: When its normal screen size: http://foto.pk/images/minx.png[^] When its maximized: http://foto.pk/images/maxx.png[^] ------------------------------------------------------------- Btw. You asked why would I want to know this value before... Answer) I don't actually want to show users "yay u reached the bottom" lol. I want the program to get more tweets when it reaches there. The above that I am making is a v2 of my current twitter client called TRocket. TRocket - Twitter Client [Open Source][^]

                N 1 Reply Last reply
                0
                • A Ammar_Ahmad

                  Oh that kinda worked... but how am I ganna calculate the value in a control like this one: When its normal screen size: http://foto.pk/images/minx.png[^] When its maximized: http://foto.pk/images/maxx.png[^] ------------------------------------------------------------- Btw. You asked why would I want to know this value before... Answer) I don't actually want to show users "yay u reached the bottom" lol. I want the program to get more tweets when it reaches there. The above that I am making is a v2 of my current twitter client called TRocket. TRocket - Twitter Client [Open Source][^]

                  N Offline
                  N Offline
                  Nick Otten
                  wrote on last edited by
                  #19

                  How do you fill the listbox? with a loop or a data binding? EDIT: oke something just shot to my mind. the items you add to your listbox are controls right? i forgot the object name but i've seen the code of those. this means they have a fixed sized right? you could calculate how much fit into your listbox if you read out the length and hight of it. lets say for example your listbox is 300 pixels wide and 400 pixels high. your controls are 100 wide and 50 high. this would mean you can fit 3 rows of each 8 items = 24 items without scroll bar. so in a 'math' way:

                  [ammount of items] - (math.floor([with_listbox]/[with_control])+math.floor([hight_listbox]/[hight_control])) = maximum scroll value

                  ------------------- Ah oke, yea now its making sense ;) and i already figured it was for Trocket (read the thread about it) when i was helping you with a previous question.

                  A 1 Reply Last reply
                  0
                  • N Nick Otten

                    How do you fill the listbox? with a loop or a data binding? EDIT: oke something just shot to my mind. the items you add to your listbox are controls right? i forgot the object name but i've seen the code of those. this means they have a fixed sized right? you could calculate how much fit into your listbox if you read out the length and hight of it. lets say for example your listbox is 300 pixels wide and 400 pixels high. your controls are 100 wide and 50 high. this would mean you can fit 3 rows of each 8 items = 24 items without scroll bar. so in a 'math' way:

                    [ammount of items] - (math.floor([with_listbox]/[with_control])+math.floor([hight_listbox]/[hight_control])) = maximum scroll value

                    ------------------- Ah oke, yea now its making sense ;) and i already figured it was for Trocket (read the thread about it) when i was helping you with a previous question.

                    A Offline
                    A Offline
                    Ammar_Ahmad
                    wrote on last edited by
                    #20

                    huh? Sorry but I didn't quiet get that... wasn't quiet good in maths :/ Can you check into the source code: http://www.mediafire.com/?m13i05h0vmb11yc[^] I actually want this to be on Flowlayoutpanel1.

                    N 1 Reply Last reply
                    0
                    • A Ammar_Ahmad

                      huh? Sorry but I didn't quiet get that... wasn't quiet good in maths :/ Can you check into the source code: http://www.mediafire.com/?m13i05h0vmb11yc[^] I actually want this to be on Flowlayoutpanel1.

                      N Offline
                      N Offline
                      Nick Otten
                      wrote on last edited by
                      #21

                      Private Function CalculateMaxScrollValue(ByVal totalitems As Int64, ByVal controlhight As Int32, ByVal controlwith As Int32)
                      'NOTE: 482 and 114 is the size property of your msgctrl.vb
                      Return totalitems - (Math.Floor(controlwith / 482) * Math.Floor(controlhight / 114))
                      End Function

                      Add that function to your code to find the max scroll value. Use that in combination with the code i send you in the previous posts in this topic. replace the txtscroll with the flowlayoutpanel1 and it should work (cant test it here). as a side note: you might want to fine tune the if/else of mine a little to a "<" instead of "=". giving a exact value to a 'analog' control gives it a small change to trigger. also it seems like the program is single threaded. i don't know how long it takes to load those messages but your interface will hang (not responding ect) till the load is complete. looking into threading might be interesting.

                      A 1 Reply Last reply
                      0
                      • N Nick Otten

                        Private Function CalculateMaxScrollValue(ByVal totalitems As Int64, ByVal controlhight As Int32, ByVal controlwith As Int32)
                        'NOTE: 482 and 114 is the size property of your msgctrl.vb
                        Return totalitems - (Math.Floor(controlwith / 482) * Math.Floor(controlhight / 114))
                        End Function

                        Add that function to your code to find the max scroll value. Use that in combination with the code i send you in the previous posts in this topic. replace the txtscroll with the flowlayoutpanel1 and it should work (cant test it here). as a side note: you might want to fine tune the if/else of mine a little to a "<" instead of "=". giving a exact value to a 'analog' control gives it a small change to trigger. also it seems like the program is single threaded. i don't know how long it takes to load those messages but your interface will hang (not responding ect) till the load is complete. looking into threading might be interesting.

                        A Offline
                        A Offline
                        Ammar_Ahmad
                        wrote on last edited by
                        #22

                        Err my laptops fan got fried - is at the repair shop. - sorry for the late reply... Anyway. So you mean I should just call this function on load? and replace the maxscroll = index - 18 on load?

                        N 1 Reply Last reply
                        0
                        • A Ammar_Ahmad

                          Err my laptops fan got fried - is at the repair shop. - sorry for the late reply... Anyway. So you mean I should just call this function on load? and replace the maxscroll = index - 18 on load?

                          N Offline
                          N Offline
                          Nick Otten
                          wrote on last edited by
                          #23

                          Hey, Sorry for my late response. I unfortunately fell ill. to get back to your question: No, you call that function every time after the amount of items in your flowlayoutpanel changes.

                          A 1 Reply Last reply
                          0
                          • N Nick Otten

                            Hey, Sorry for my late response. I unfortunately fell ill. to get back to your question: No, you call that function every time after the amount of items in your flowlayoutpanel changes.

                            A Offline
                            A Offline
                            Ammar_Ahmad
                            wrote on last edited by
                            #24

                            so all the code needs to be same. but what should I do with: maxscroll = index - 18 ? the index property was giving an error in flowlayoutpanel. can you give me the example on the same code or better on the project its self.. :

                            Imports System.Runtime.InteropServices

                            Public Class Form1
                            Dim WithEvents scrollhandler As MyListener 'class that will watch windows to see if your scrolling
                            Private scrolled As Boolean = False 'boolean you can use to flip if a message box was displayed or not...(so it wont loop the messagebox.show)
                            Private maxscroll As Int64 'int used to store the max value of the scrollbar
                            'dll used to get the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                            _
                            Public Shared Function GetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer) As Integer
                            End Function

                            'dll used to set the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                            \_
                            Private Shared Function SetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer, ByVal nPos As Integer, ByVal bRedraw As Boolean) As Integer
                            End Function
                            
                            Private Const SB\_HORZ As Integer = &H0
                            Private Const SB\_VERT As Integer = &H1
                            
                            
                            Public Property HScrollPos() As Integer 'property to set or get the horisontal scrollbar value
                                Get
                                    Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ) 'change txtscroll to the control you use. dont forget the .handle
                                End Get
                                Set(ByVal value As Integer)
                                    SetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ, value, True) 'change txtscroll to the control you use. dont forget the .handle
                                End Set
                            End Property
                            
                            
                            Public Property VScrollPos() As Integer 'Property to set or get the Vertical scrollbar value
                                Get
                                    Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_VERT) 'change txtscroll to the control you use. dont forget the .handle
                                End Get
                                Set(ByVal value As Integer)
                                    SetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_VERT, value, True) 'change txtscroll to the control you use. dont forget the .handle
                                End Set
                            End Property
                            
                            Private Sub Form1\_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
                                'some random loop i used to ditch some data in my listbox for testing
                            
                            N 1 Reply Last reply
                            0
                            • A Ammar_Ahmad

                              so all the code needs to be same. but what should I do with: maxscroll = index - 18 ? the index property was giving an error in flowlayoutpanel. can you give me the example on the same code or better on the project its self.. :

                              Imports System.Runtime.InteropServices

                              Public Class Form1
                              Dim WithEvents scrollhandler As MyListener 'class that will watch windows to see if your scrolling
                              Private scrolled As Boolean = False 'boolean you can use to flip if a message box was displayed or not...(so it wont loop the messagebox.show)
                              Private maxscroll As Int64 'int used to store the max value of the scrollbar
                              'dll used to get the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                              _
                              Public Shared Function GetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer) As Integer
                              End Function

                              'dll used to set the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                              \_
                              Private Shared Function SetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer, ByVal nPos As Integer, ByVal bRedraw As Boolean) As Integer
                              End Function
                              
                              Private Const SB\_HORZ As Integer = &H0
                              Private Const SB\_VERT As Integer = &H1
                              
                              
                              Public Property HScrollPos() As Integer 'property to set or get the horisontal scrollbar value
                                  Get
                                      Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ) 'change txtscroll to the control you use. dont forget the .handle
                                  End Get
                                  Set(ByVal value As Integer)
                                      SetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ, value, True) 'change txtscroll to the control you use. dont forget the .handle
                                  End Set
                              End Property
                              
                              
                              Public Property VScrollPos() As Integer 'Property to set or get the Vertical scrollbar value
                                  Get
                                      Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_VERT) 'change txtscroll to the control you use. dont forget the .handle
                                  End Get
                                  Set(ByVal value As Integer)
                                      SetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_VERT, value, True) 'change txtscroll to the control you use. dont forget the .handle
                                  End Set
                              End Property
                              
                              Private Sub Form1\_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
                                  'some random loop i used to ditch some data in my listbox for testing
                              
                              N Offline
                              N Offline
                              Nick Otten
                              wrote on last edited by
                              #25

                              hmm oke i admid my code was a bit of mess. i cleared it out a bit and made a example program so you can see how it works. Please follow the below steps. 1. start a new form project 2. Add is Listbox. set the name to txtscroll and the size to 254; 381 3. Add a button, call this one btnadd 4. copy paste the following code into the project (under the form you just made)

                              Imports System.Runtime.InteropServices

                              Public Class Form1

                              #Region "declarations"
                              Dim WithEvents scrollhandler As MyListener 'class that will watch windows to see if your scrolling
                              Private scrolled As Boolean = False 'boolean you can use to flip if a message box was displayed or not...(so it wont loop the messagebox.show)
                              Private maxscroll As Int64 'int used to store the max value of the scrollbar
                              Private index As Int32 = 0 'used for random loops to fill the txtscroll
                              Private Const SB_HORZ As Integer = &H0
                              Private Const SB_VERT As Integer = &H1
                              #End Region

                              #Region "dll calls"
                              'dll used to get the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                              _
                              Public Shared Function GetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer) As Integer
                              End Function

                              'dll used to set the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                               \_
                              Private Shared Function SetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer, ByVal nPos As Integer, ByVal bRedraw As Boolean) As Integer
                              End Function
                              

                              #End Region

                              Public Property HScrollPos() As Integer 'property to set or get the horisontal scrollbar value
                                  Get
                                      Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ) 'change txtscroll to the control you use. dont forget the .handle
                                  End Get
                                  Set(ByVal value As Integer)
                                      SetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ, value, True) 'change txtscroll to the control you use. dont forget the .handle
                                  End Set
                              End Property
                              
                              
                              Public Property VScrollPos() As Integer 'Property to set or get the Vertical scrollbar value
                                  Get
                                      Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_VERT) 'change txtscroll to the control you use. dont forget the .handle
                                  End Get
                                  Set(ByVal value As Integer)
                                      SetScrollPos(DirectCast(txtscroll.Handle, IntPtr
                              
                              A 1 Reply Last reply
                              0
                              • N Nick Otten

                                hmm oke i admid my code was a bit of mess. i cleared it out a bit and made a example program so you can see how it works. Please follow the below steps. 1. start a new form project 2. Add is Listbox. set the name to txtscroll and the size to 254; 381 3. Add a button, call this one btnadd 4. copy paste the following code into the project (under the form you just made)

                                Imports System.Runtime.InteropServices

                                Public Class Form1

                                #Region "declarations"
                                Dim WithEvents scrollhandler As MyListener 'class that will watch windows to see if your scrolling
                                Private scrolled As Boolean = False 'boolean you can use to flip if a message box was displayed or not...(so it wont loop the messagebox.show)
                                Private maxscroll As Int64 'int used to store the max value of the scrollbar
                                Private index As Int32 = 0 'used for random loops to fill the txtscroll
                                Private Const SB_HORZ As Integer = &H0
                                Private Const SB_VERT As Integer = &H1
                                #End Region

                                #Region "dll calls"
                                'dll used to get the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                                _
                                Public Shared Function GetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer) As Integer
                                End Function

                                'dll used to set the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                                 \_
                                Private Shared Function SetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer, ByVal nPos As Integer, ByVal bRedraw As Boolean) As Integer
                                End Function
                                

                                #End Region

                                Public Property HScrollPos() As Integer 'property to set or get the horisontal scrollbar value
                                    Get
                                        Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ) 'change txtscroll to the control you use. dont forget the .handle
                                    End Get
                                    Set(ByVal value As Integer)
                                        SetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_HORZ, value, True) 'change txtscroll to the control you use. dont forget the .handle
                                    End Set
                                End Property
                                
                                
                                Public Property VScrollPos() As Integer 'Property to set or get the Vertical scrollbar value
                                    Get
                                        Return GetScrollPos(DirectCast(txtscroll.Handle, IntPtr), SB\_VERT) 'change txtscroll to the control you use. dont forget the .handle
                                    End Get
                                    Set(ByVal value As Integer)
                                        SetScrollPos(DirectCast(txtscroll.Handle, IntPtr
                                
                                A Offline
                                A Offline
                                Ammar_Ahmad
                                wrote on last edited by
                                #26

                                Alright so here is what I got so far:

                                Dim WithEvents scrollhandler As MyListener 'class that will watch windows to see if your scrolling
                                Private scrolled As Boolean = False 'boolean you can use to flip if a message box was displayed or not...(so it wont loop the messagebox.show)
                                Private maxscroll As Int64 'int used to store the max value of the scrollbar
                                ' Private index As Int32 = 0 'used for random loops to fill the txtscroll
                                Private Const SB_HORZ As Integer = &H0
                                Private Const SB_VERT As Integer = &H1

                                'dll used to get the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                                 \_
                                Public Shared Function GetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer) As Integer
                                End Function
                                
                                'dll used to set the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                                 \_
                                Private Shared Function SetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer, ByVal nPos As Integer, ByVal bRedraw As Boolean) As Integer
                                End Function
                                
                                
                                Public Property HScrollPos() As Integer 'property to set or get the horisontal scrollbar value
                                    Get
                                        Return GetScrollPos(DirectCast(FlowLayoutPanel1.Handle, IntPtr), SB\_HORZ) 'change txtscroll to the control you use. dont forget the .handle
                                    End Get
                                    Set(ByVal value As Integer)
                                        SetScrollPos(DirectCast(FlowLayoutPanel1.Handle, IntPtr), SB\_HORZ, value, True) 'change txtscroll to the control you use. dont forget the .handle
                                    End Set
                                End Property
                                
                                
                                Public Property VScrollPos() As Integer 'Property to set or get the Vertical scrollbar value
                                    Get
                                        Return GetScrollPos(DirectCast(FlowLayoutPanel1.Handle, IntPtr), SB\_VERT) 'change txtscroll to the control you use. dont forget the .handle
                                    End Get
                                    Set(ByVal value As Integer)
                                        SetScrollPos(DirectCast(FlowLayoutPanel1.Handle, IntPtr), SB\_VERT, value, True) 'change txtscroll to the control you use. dont forget the .handle
                                    End Set
                                End Property
                                
                                'will add load in the end.
                                
                                Private Sub FlowLayoutPanel1\_MouseWheelScroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles FlowLayoutPanel1.MouseWheel
                                    scrollhandler\_MyScroll(e, e) 'needed to catch the scrollwheel event.
                                End Sub
                                
                                
                                Private Sub scrollhandler\_MyScroll(ByVal sender As Object, ByVal
                                
                                N 1 Reply Last reply
                                0
                                • A Ammar_Ahmad

                                  Alright so here is what I got so far:

                                  Dim WithEvents scrollhandler As MyListener 'class that will watch windows to see if your scrolling
                                  Private scrolled As Boolean = False 'boolean you can use to flip if a message box was displayed or not...(so it wont loop the messagebox.show)
                                  Private maxscroll As Int64 'int used to store the max value of the scrollbar
                                  ' Private index As Int32 = 0 'used for random loops to fill the txtscroll
                                  Private Const SB_HORZ As Integer = &H0
                                  Private Const SB_VERT As Integer = &H1

                                  'dll used to get the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                                   \_
                                  Public Shared Function GetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer) As Integer
                                  End Function
                                  
                                  'dll used to set the scrollbar value NOTE: if the scrollbar is not visible or you go higher then your max it will crash!
                                   \_
                                  Private Shared Function SetScrollPos(ByVal hWnd As IntPtr, ByVal nBar As Integer, ByVal nPos As Integer, ByVal bRedraw As Boolean) As Integer
                                  End Function
                                  
                                  
                                  Public Property HScrollPos() As Integer 'property to set or get the horisontal scrollbar value
                                      Get
                                          Return GetScrollPos(DirectCast(FlowLayoutPanel1.Handle, IntPtr), SB\_HORZ) 'change txtscroll to the control you use. dont forget the .handle
                                      End Get
                                      Set(ByVal value As Integer)
                                          SetScrollPos(DirectCast(FlowLayoutPanel1.Handle, IntPtr), SB\_HORZ, value, True) 'change txtscroll to the control you use. dont forget the .handle
                                      End Set
                                  End Property
                                  
                                  
                                  Public Property VScrollPos() As Integer 'Property to set or get the Vertical scrollbar value
                                      Get
                                          Return GetScrollPos(DirectCast(FlowLayoutPanel1.Handle, IntPtr), SB\_VERT) 'change txtscroll to the control you use. dont forget the .handle
                                      End Get
                                      Set(ByVal value As Integer)
                                          SetScrollPos(DirectCast(FlowLayoutPanel1.Handle, IntPtr), SB\_VERT, value, True) 'change txtscroll to the control you use. dont forget the .handle
                                      End Set
                                  End Property
                                  
                                  'will add load in the end.
                                  
                                  Private Sub FlowLayoutPanel1\_MouseWheelScroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles FlowLayoutPanel1.MouseWheel
                                      scrollhandler\_MyScroll(e, e) 'needed to catch the scrollwheel event.
                                  End Sub
                                  
                                  
                                  Private Sub scrollhandler\_MyScroll(ByVal sender As Object, ByVal
                                  
                                  N Offline
                                  N Offline
                                  Nick Otten
                                  wrote on last edited by
                                  #27

                                  It seems your making a mistake in providing the arguemnts for your max scroll.

                                  Quote:

                                  Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load scrollhandler = New MyListener(FlowLayoutPanel1) maxscroll = CalcMaxScroll(FlowLayoutPanel1.Size.Height, FlowLayoutPanel1.Size.Width, 114, 1075, 19) '19 number of tweets '114 height of tweettimelinecontrol '1075 width of flowlayoutpanel1 'last number tells the number of items. (read that from a global var) End Sub

                                  You say that the with of your flowlayoutpanel is 1075. yet you apply it to the formula as the with of your tweettimelinecontrol. quoting you from a previous post:

                                  Quote:

                                  Oh that kinda worked... but how am I ganna calculate the value in a control like this one: When its normal screen size: http://foto.pk/images/minx.png\[^\]

                                  you can see in the screenshot that you got 2 of those controls next to eachoter so it can never be the total size of your flowlayoutpanel. please check the with property of your Tweettimelinecontrol and change the value. while your at it also change the 19 with a flowlayoutpanel.items.count to make sure it are 19.

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