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  4. How to find change in display ?

How to find change in display ?

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  • J Offline
    J Offline
    Jijo Raj
    wrote on last edited by
    #1

    Hai all, Im planning to do a project which can remotely access a pc. For that i want to find, whether there is any change in the clients display. But when i hook WM_PAINT, a lot of paint messages are comming even if the machine is idle. Can anyone tell me an idea to solve this ? thanx in advance. Regards, Jijo. ________________________________ Yesterday is history, Tomorrow is a mystery, But today is a present.

    L 1 Reply Last reply
    0
    • J Jijo Raj

      Hai all, Im planning to do a project which can remotely access a pc. For that i want to find, whether there is any change in the clients display. But when i hook WM_PAINT, a lot of paint messages are comming even if the machine is idle. Can anyone tell me an idea to solve this ? thanx in advance. Regards, Jijo. ________________________________ Yesterday is history, Tomorrow is a mystery, But today is a present.

      L Offline
      L Offline
      Lost User
      wrote on last edited by
      #2

      Have you tried the WM_DISPLAYCHANGE message?

      J 1 Reply Last reply
      0
      • L Lost User

        Have you tried the WM_DISPLAYCHANGE message?

        J Offline
        J Offline
        Jijo Raj
        wrote on last edited by
        #3

        Dear Greeeg, Thanx a lot for your valuable reply. But one doubt. When i tried to spy the WM_DISPLAYCHANGE message using Spy++, i can't find any WM_DISPLAYCHANGE message generating, when i open/move/close windows. Please clear this doubt. Regards, Jijo. ________________________________ Yesterday is history, Tomorrow is a mystery, But today is a present.

        G 1 Reply Last reply
        0
        • J Jijo Raj

          Dear Greeeg, Thanx a lot for your valuable reply. But one doubt. When i tried to spy the WM_DISPLAYCHANGE message using Spy++, i can't find any WM_DISPLAYCHANGE message generating, when i open/move/close windows. Please clear this doubt. Regards, Jijo. ________________________________ Yesterday is history, Tomorrow is a mystery, But today is a present.

          G Offline
          G Offline
          grigsoft
          wrote on last edited by
          #4

          Unless you are doing this as programming excersize, I could recommend forgetting it. Either use existing tool(RAdmin, NetMeeting, PCAnywhere) for your own needs, or find another tool to create for selling. Catching image is just a beginning, and if you have problems with it, probably you are not good enough to do it. No offences, I'm also not qualified enough. But you will have to find a way for real-time image differencing and packing. Or did you think you could get enough perfomance by sending full screen/window image over a network? Think again. And finally you will stuck at what a friend of mine did, he made all this path, only to find out that to get true speed he have to develop special screen driver (as far as I understood), which market leaders already have. Otherwise you have speed limit that you will reach by making a screenshot - just consider copying, comparison and packing of 1024x768x16bit = 1.5 Mg image and do it 10-20 times per second. PS. WM_DISPLAYCHANGE comes when screen resolution changes. Igor Green http://www.grigsoft.com/ - files and folders comparison tools

          J 1 Reply Last reply
          0
          • G grigsoft

            Unless you are doing this as programming excersize, I could recommend forgetting it. Either use existing tool(RAdmin, NetMeeting, PCAnywhere) for your own needs, or find another tool to create for selling. Catching image is just a beginning, and if you have problems with it, probably you are not good enough to do it. No offences, I'm also not qualified enough. But you will have to find a way for real-time image differencing and packing. Or did you think you could get enough perfomance by sending full screen/window image over a network? Think again. And finally you will stuck at what a friend of mine did, he made all this path, only to find out that to get true speed he have to develop special screen driver (as far as I understood), which market leaders already have. Otherwise you have speed limit that you will reach by making a screenshot - just consider copying, comparison and packing of 1024x768x16bit = 1.5 Mg image and do it 10-20 times per second. PS. WM_DISPLAYCHANGE comes when screen resolution changes. Igor Green http://www.grigsoft.com/ - files and folders comparison tools

            J Offline
            J Offline
            Jijo Raj
            wrote on last edited by
            #5

            Dear Igor, Thanks for ur valuable reply. Im just doing this project for improving my knowledge. :D And now i understood that the full screencapture method was utter foolishness. :(( And will you please explane that screen driver method, more clearly ? is that hooking the display driver ? or something like that ? Can you please provide me some helpful links about that ? Regards, Jijo. ;) ________________________________ Yesterday is history, Tomorrow is a mystery, But today is a present.

            G 1 Reply Last reply
            0
            • J Jijo Raj

              Dear Igor, Thanks for ur valuable reply. Im just doing this project for improving my knowledge. :D And now i understood that the full screencapture method was utter foolishness. :(( And will you please explane that screen driver method, more clearly ? is that hooking the display driver ? or something like that ? Can you please provide me some helpful links about that ? Regards, Jijo. ;) ________________________________ Yesterday is history, Tomorrow is a mystery, But today is a present.

              G Offline
              G Offline
              grigsoft
              wrote on last edited by
              #6

              No, sorry, I don't know the details myself. But for your own needs screen capturing is good enough. As far as I could understood, that 'driver' just provide you direct access to screen picture, which let you skip one step from process - preparing and copying picture to intenal bitmap. Still you have to do all differencing and packing yourself. Igor Green http://www.grigsoft.com/ - files and folders comparison tools

              J 1 Reply Last reply
              0
              • G grigsoft

                No, sorry, I don't know the details myself. But for your own needs screen capturing is good enough. As far as I could understood, that 'driver' just provide you direct access to screen picture, which let you skip one step from process - preparing and copying picture to intenal bitmap. Still you have to do all differencing and packing yourself. Igor Green http://www.grigsoft.com/ - files and folders comparison tools

                J Offline
                J Offline
                Jijo Raj
                wrote on last edited by
                #7

                okay Igor... Thanx a lot. Regards, Jijo. ________________________________ Yesterday is history, Tomorrow is a mystery, But today is a present.

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