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  4. how to use delegate to call function and introduce function as content?

how to use delegate to call function and introduce function as content?

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  • B BillWoodruff

    This code makes no sense: you call method 'fun1 with two arguments, but method 'fun1 takes no parameters. All your methods, and the delegate, are defined outside the scope of the Main method: what is the enclosing Class ?

    «I want to stay as close to the edge as I can without going over. Out on the edge you see all kinds of things you can't see from the center» Kurt Vonnegut.

    S Offline
    S Offline
    smallkubi
    wrote on last edited by
    #3

    class1()
    {
    main()
    {
    int x,y,z;
    fun1(int x, fun2)
    }
    fun2(int y);
    fun3(int y,int z);
    }

    class2()
    {
    static fun1(int x, fun ?)
    {
    fun2() or fun3()
    }
    }

    P B 2 Replies Last reply
    0
    • S smallkubi

      class1()
      {
      main()
      {
      int x,y,z;
      fun1(int x, fun2)
      }
      fun2(int y);
      fun3(int y,int z);
      }

      class2()
      {
      static fun1(int x, fun ?)
      {
      fun2() or fun3()
      }
      }

      P Offline
      P Offline
      Pete OHanlon
      wrote on last edited by
      #4

      Please, show us the code you really have - don't try reinterpreting your code as it makes it impossible to understand.

      This space for rent

      1 Reply Last reply
      0
      • S smallkubi

        class1()
        {
        main()
        {
        int x,y,z;
        fun1(int x, fun2)
        }
        fun2(int y);
        fun3(int y,int z);
        }

        class2()
        {
        static fun1(int x, fun ?)
        {
        fun2() or fun3()
        }
        }

        B Offline
        B Offline
        BillWoodruff
        wrote on last edited by
        #5

        Your second code example also make no sense, and will never compile. I believe you are very "lost" in C#: now, there's nothing wrong with that; everyone here was once a "beginner," and went through some degree of confusion. Here's how to get "un-lost:" Get the Visual Studio Edition, get the free book by Charles Petzold, "Dot Net Zero" [^]. Start at the beginning of that book and study the basics of C# carefully, start programming the examples in that book. cheers, Bill

        «I want to stay as close to the edge as I can without going over. Out on the edge you see all kinds of things you can't see from the center» Kurt Vonnegut.

        S 1 Reply Last reply
        0
        • S smallkubi

          hello,i have question as follows. for example, I want to call fun1, then introduce vary x, and function as vary(fun2 or fun3), fun2 and fun3 have different varies. In fun1, can call fun2 or fun3 according to reference. I think delegate can solve it ,but fun2 and fun3 have different number input, how to do it? delegate void call() //? main() { int x,y,z; fun1(x,call) } fun1() { fun2(y) or fun3(y,z)? } fun2(int y); fun3(int y,int z);

          Richard DeemingR Offline
          Richard DeemingR Offline
          Richard Deeming
          wrote on last edited by
          #6

          Are you looking for something like this:

          static void Main()
          {
          int x = 1;
          int y = 2;
          int z = 3;

          fun1(x, () => fun2(y));
          fun1(x, () => fun3(y, z));
          

          }

          static void fun1(int x, Action call)
          {
          call();
          }

          static void fun2(int y) { ... }
          static void fun3(int y, int z) { ... }

          Lambda Expressions (C# Programming Guide)[^] C# in Depth : The Beauty of Closures[^]


          "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

          "These people looked deep within my soul and assigned me a number based on the order in which I joined" - Homer

          S 1 Reply Last reply
          0
          • B BillWoodruff

            Your second code example also make no sense, and will never compile. I believe you are very "lost" in C#: now, there's nothing wrong with that; everyone here was once a "beginner," and went through some degree of confusion. Here's how to get "un-lost:" Get the Visual Studio Edition, get the free book by Charles Petzold, "Dot Net Zero" [^]. Start at the beginning of that book and study the basics of C# carefully, start programming the examples in that book. cheers, Bill

            «I want to stay as close to the edge as I can without going over. Out on the edge you see all kinds of things you can't see from the center» Kurt Vonnegut.

            S Offline
            S Offline
            smallkubi
            wrote on last edited by
            #7

            i am sorry,indeed i am a beginner. I don't know how to meet my requirement. My requirement as follows: I want to code an optimization algrithm function to calculate Minimized value. It can input function that needed optimization, like fun2 or fun3 ,etc... that i said. It means if i input fun2 to optimization function ,it can search fun2's Minimized value, if input fun3, it can search fun3's Minimized value.But fun2 and fun3 or other functions don't have same style input variable,their input variable style and number is not same. how can i realize it?

            1 Reply Last reply
            0
            • Richard DeemingR Richard Deeming

              Are you looking for something like this:

              static void Main()
              {
              int x = 1;
              int y = 2;
              int z = 3;

              fun1(x, () => fun2(y));
              fun1(x, () => fun3(y, z));
              

              }

              static void fun1(int x, Action call)
              {
              call();
              }

              static void fun2(int y) { ... }
              static void fun3(int y, int z) { ... }

              Lambda Expressions (C# Programming Guide)[^] C# in Depth : The Beauty of Closures[^]


              "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

              S Offline
              S Offline
              smallkubi
              wrote on last edited by
              #8

              Thank you very much,it 's near my requirement. But one more requirement is that: static void fun1(int x, Action call) { call(); } take fun3(y,z) for example, call() is run fun3(y,z). but if i want to run fun3(x,z) ,how to realize it? you know ,i want to change y value in fun1 to call fun2(int y) or fun3(int y,int z),because my code use loop to change y value in fun1,to let fun2 or fun3 be a minimum value.

              Richard DeemingR 1 Reply Last reply
              0
              • S smallkubi

                Thank you very much,it 's near my requirement. But one more requirement is that: static void fun1(int x, Action call) { call(); } take fun3(y,z) for example, call() is run fun3(y,z). but if i want to run fun3(x,z) ,how to realize it? you know ,i want to change y value in fun1 to call fun2(int y) or fun3(int y,int z),because my code use loop to change y value in fun1,to let fun2 or fun3 be a minimum value.

                Richard DeemingR Offline
                Richard DeemingR Offline
                Richard Deeming
                wrote on last edited by
                #9

                So something like this:

                static void Main()
                {
                int x = 1;
                int z = 3;
                fun1(x, y => fun2(y));
                fun1(x, y => fun3(y, z));
                }

                static void fun1(int x, Action<int> call)
                {
                call(x);
                }

                static void fun2(int y) { ... }
                static void fun3(int y, int z) { ... }


                "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                "These people looked deep within my soul and assigned me a number based on the order in which I joined" - Homer

                S 2 Replies Last reply
                0
                • Richard DeemingR Richard Deeming

                  So something like this:

                  static void Main()
                  {
                  int x = 1;
                  int z = 3;
                  fun1(x, y => fun2(y));
                  fun1(x, y => fun3(y, z));
                  }

                  static void fun1(int x, Action<int> call)
                  {
                  call(x);
                  }

                  static void fun2(int y) { ... }
                  static void fun3(int y, int z) { ... }


                  "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                  S Offline
                  S Offline
                  smallkubi
                  wrote on last edited by
                  #10

                  Great Job!!! Thank you very much. And i have other question bothering me. I have to use chart control to plot 10 series including 1000 points per series in one chartarea. But after ploting, mouse move or zoom in or ContextMenuStrip operation is very slow and delay. I think maybe paint problem. When i ask before, i get the answer is point number is too big. But i found that if i plot 200 series with 1 point for example as follows, the operation is also slow. How can treat it? follows is for example: Series series1; for(int i=0;i<200;i++) { series1=new series(); series1.Points.Add(new DataPoint(i,i)); chart1.Series.Add(series1); }

                  L 1 Reply Last reply
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                  • S smallkubi

                    Great Job!!! Thank you very much. And i have other question bothering me. I have to use chart control to plot 10 series including 1000 points per series in one chartarea. But after ploting, mouse move or zoom in or ContextMenuStrip operation is very slow and delay. I think maybe paint problem. When i ask before, i get the answer is point number is too big. But i found that if i plot 200 series with 1 point for example as follows, the operation is also slow. How can treat it? follows is for example: Series series1; for(int i=0;i<200;i++) { series1=new series(); series1.Points.Add(new DataPoint(i,i)); chart1.Series.Add(series1); }

                    L Offline
                    L Offline
                    Lost User
                    wrote on last edited by
                    #11

                    smallkubi wrote:

                    I think maybe paint problem.

                    Why?

                    smallkubi wrote:

                    When i ask before, i get the answer is point number is too big.

                    The more points you need to draw, the longer it takes. If there had been a useless delay in the chart-control, people would have noticed.

                    Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^][](X-Clacks-Overhead: GNU Terry Pratchett)

                    S 1 Reply Last reply
                    0
                    • L Lost User

                      smallkubi wrote:

                      I think maybe paint problem.

                      Why?

                      smallkubi wrote:

                      When i ask before, i get the answer is point number is too big.

                      The more points you need to draw, the longer it takes. If there had been a useless delay in the chart-control, people would have noticed.

                      Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^][](X-Clacks-Overhead: GNU Terry Pratchett)

                      S Offline
                      S Offline
                      smallkubi
                      wrote on last edited by
                      #12

                      I mean Dalay is not that Chart generating process is slow, when i finished plot, i want to operate on Chart, like mouse moving, Scroll... is slow.

                      L 1 Reply Last reply
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                      • S smallkubi

                        I mean Dalay is not that Chart generating process is slow, when i finished plot, i want to operate on Chart, like mouse moving, Scroll... is slow.

                        L Offline
                        L Offline
                        Lost User
                        wrote on last edited by
                        #13

                        Meaning it will have to recalculate which part it should show and repaint it. That takes time. Smaller charts with less points will be faster. If you find that the Chart-control is "too slow" for your needs, you may have to implement your own.

                        Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^][](X-Clacks-Overhead: GNU Terry Pratchett)

                        S 1 Reply Last reply
                        0
                        • L Lost User

                          Meaning it will have to recalculate which part it should show and repaint it. That takes time. Smaller charts with less points will be faster. If you find that the Chart-control is "too slow" for your needs, you may have to implement your own.

                          Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^][](X-Clacks-Overhead: GNU Terry Pratchett)

                          S Offline
                          S Offline
                          smallkubi
                          wrote on last edited by
                          #14

                          oh, do you know how to stop control auto refresh? i think if i can refresh it in mannual?

                          L 1 Reply Last reply
                          0
                          • S smallkubi

                            oh, do you know how to stop control auto refresh? i think if i can refresh it in mannual?

                            L Offline
                            L Offline
                            Lost User
                            wrote on last edited by
                            #15

                            Stop the user from scrolling, panning and/or zooming, and you don't need to refresh. If anything changes, a refresh would be required to get the updated data on screen.

                            Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^][](X-Clacks-Overhead: GNU Terry Pratchett)

                            S 1 Reply Last reply
                            0
                            • L Lost User

                              Stop the user from scrolling, panning and/or zooming, and you don't need to refresh. If anything changes, a refresh would be required to get the updated data on screen.

                              Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^][](X-Clacks-Overhead: GNU Terry Pratchett)

                              S Offline
                              S Offline
                              smallkubi
                              wrote on last edited by
                              #16

                              Now i want to have the function of Zooming,scrolling... Anything changes, screen don't update automatically,I want to updated data on screen mannully, can it be possible?

                              L 1 Reply Last reply
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                              • S smallkubi

                                Now i want to have the function of Zooming,scrolling... Anything changes, screen don't update automatically,I want to updated data on screen mannully, can it be possible?

                                L Offline
                                L Offline
                                Lost User
                                wrote on last edited by
                                #17

                                Sure; use the drawing functions to draw your chart. Means writing code to calculate the length of the axes, drawing each point, drawing some labels.

                                Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^][](X-Clacks-Overhead: GNU Terry Pratchett)

                                1 Reply Last reply
                                0
                                • Richard DeemingR Richard Deeming

                                  So something like this:

                                  static void Main()
                                  {
                                  int x = 1;
                                  int z = 3;
                                  fun1(x, y => fun2(y));
                                  fun1(x, y => fun3(y, z));
                                  }

                                  static void fun1(int x, Action<int> call)
                                  {
                                  call(x);
                                  }

                                  static void fun2(int y) { ... }
                                  static void fun3(int y, int z) { ... }


                                  "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                                  S Offline
                                  S Offline
                                  smallkubi
                                  wrote on last edited by
                                  #18

                                  Hi, i have another question... If i want to use multi-thread to call fun1, how can i input the variable x, y,z? for example: static void Main() { int x = 1; int z = 3; Thread th=new Thread(fun1( ? )) //how can i do ? th.start(); // fun1(x, y => fun2(y)); // fun1(x, y => fun3(y, z)); } static void fun1(int x, Action call) { call(x); } static void fun2(int y) { ... } static void fun3(int y, int z) { ... }

                                  Richard DeemingR 1 Reply Last reply
                                  0
                                  • S smallkubi

                                    Hi, i have another question... If i want to use multi-thread to call fun1, how can i input the variable x, y,z? for example: static void Main() { int x = 1; int z = 3; Thread th=new Thread(fun1( ? )) //how can i do ? th.start(); // fun1(x, y => fun2(y)); // fun1(x, y => fun3(y, z)); } static void fun1(int x, Action call) { call(x); } static void fun2(int y) { ... } static void fun3(int y, int z) { ... }

                                    Richard DeemingR Offline
                                    Richard DeemingR Offline
                                    Richard Deeming
                                    wrote on last edited by
                                    #19

                                    Something like this:

                                    Thread th = new Thread(() => fun1(x, y => fun3(y, z)));

                                    Breaking it down:

                                    Action<int> call = y => fun3(y, z);
                                    ThreadStart start = () => fun1(x, call);
                                    Thread th = new Thread(start);


                                    "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                                    "These people looked deep within my soul and assigned me a number based on the order in which I joined" - Homer

                                    S 2 Replies Last reply
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                                    • Richard DeemingR Richard Deeming

                                      Something like this:

                                      Thread th = new Thread(() => fun1(x, y => fun3(y, z)));

                                      Breaking it down:

                                      Action<int> call = y => fun3(y, z);
                                      ThreadStart start = () => fun1(x, call);
                                      Thread th = new Thread(start);


                                      "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                                      S Offline
                                      S Offline
                                      smallkubi
                                      wrote on last edited by
                                      #20

                                      Good Idea,i meet it. And if i have a button at main Thread , it can abort Thread "th". How to code button click function? And, if whether Thread th end or abort, i want to run" MessageBox.Show("Thread end")", how can i do it?

                                      Richard DeemingR 1 Reply Last reply
                                      0
                                      • S smallkubi

                                        Good Idea,i meet it. And if i have a button at main Thread , it can abort Thread "th". How to code button click function? And, if whether Thread th end or abort, i want to run" MessageBox.Show("Thread end")", how can i do it?

                                        Richard DeemingR Offline
                                        Richard DeemingR Offline
                                        Richard Deeming
                                        wrote on last edited by
                                        #21

                                        smallkubi wrote:

                                        it can abort Thread "th"

                                        Don't. How To Stop a Thread in .NET (and Why Thread.Abort is Evil)[^] If you're using .NET 4.5 or above, you'd probably have better luck using async and await. Asynchronous Programming with Async and Await (C# and Visual Basic)[^] Otherwise, use something like the BackgroundWorker component[^].


                                        "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                                        "These people looked deep within my soul and assigned me a number based on the order in which I joined" - Homer

                                        1 Reply Last reply
                                        0
                                        • Richard DeemingR Richard Deeming

                                          Something like this:

                                          Thread th = new Thread(() => fun1(x, y => fun3(y, z)));

                                          Breaking it down:

                                          Action<int> call = y => fun3(y, z);
                                          ThreadStart start = () => fun1(x, call);
                                          Thread th = new Thread(start);


                                          "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                                          S Offline
                                          S Offline
                                          smallkubi
                                          wrote on last edited by
                                          #22

                                          hi, If i use Func call= y=>fun3(y,z) , fun3 can be one output param function. But if my function need 2 or more output, how can i do it?

                                          Richard DeemingR 1 Reply Last reply
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