存储来自回调 (FLTK) 的 Fl:Button 值

Posted 2023-02-21

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【中文标题】存储来自回调 (FLTK) 的 Fl:Button 值【英文标题】：Store Fl:Button value from callback (FLTK) 【发布时间】：2015-12-10 20:32:49 【问题描述】：

我正在尝试使用 FLTK 库编写一个模拟国际象棋游戏的程序。

我的问题是我想对二维按钮数组进行两次回调，我想单击一个按钮，然后单击另一个按钮，当单击第二个按钮时，将第一个按钮的标签切换到标签第二个按钮的标签，然后删除第一个按钮的标签。

我觉得我需要以某种方式存储单击的第一个按钮的值，例如，如果我单击 FBoard[1][2]，我有一个等于 FBoard[1][2] 的变量并打开第二次点击将 FBoard[1][2] 的标签替换为空白（假设 FBoard[1][2] 是板上的一个单元格，上面有一块。但我不确定如何或即使这是正确的方法。

这是cpp文件：

  #include"Window.h"
  #include"ChessBoard.h"

  const char *  DisplayWindow::LastLabel;
  bool   DisplayWindow::flag;
  DisplayWindow::DisplayWindow(int width, int height, const char*)
  :Fl_Window(800, 650, "Chess")   


                for (int X = 0; X <= 7; ++X)
                    for (int Y = 0; Y <= 7; ++Y)
                    // Leaves all positions that arent occupied by
                    // a figure at the start of the game blank
                        FBoard[X][Y] = new Fl_Button(10 + 50*Y, 100 + 50*X, 50, 50,"");
                        FBoard[X][Y]->callback((Fl_Callback*)DisplayWindow::ChangeButton);
                    
                

         flag = false;
         MakeLabel(); 
         LabelButton(); 
         show();



 DisplayWindow::~DisplayWindow()

 void DisplayWindow::MakeLabel()

  for (int X = 0; X <= 7; ++X)
    for (int Y = 0; Y <= 7; ++Y)

            LBoard[X][Y] = ("  ");
    
  

  for (int X = 0; X <= 7; ++X) 
        LBoard[1][X] = ("WP");
    // Occupies second row with white pawns

  
    LBoard[0][0] = ("WR");
    LBoard[0][1] = ("WH");
    LBoard[0][2] = ("WB");
    LBoard[0][3] = ("WQ");
    LBoard[0][4] = ("WK");
    LBoard[0][5] = ("WB");
    LBoard[0][6] = ("WH");
    LBoard[0][7] = ("WR");


  for (int X = 0; X <= 7; ++X)
        LBoard[6][X] = ("BP");
  

    LBoard[7][0] = ("BR");
    LBoard[7][1] = ("BH");
    LBoard[7][2] = ("BB");
    LBoard[7][3] = ("BQ");
    LBoard[7][4] = ("BK");
    LBoard[7][5] = ("BB");
    LBoard[7][6] = ("BH");
    LBoard[7][7] = ("BR");



void DisplayWindow::LabelButton()

    for (int X = 0; X <= 7; ++X) 
        FBoard[1][X]->label(LBoard[1][X]);
    // Occupies second row with white pawns

    
    FBoard[0][0]->label(LBoard[0][0]);
    FBoard[0][1]->label(LBoard[0][1]);
    FBoard[0][2]->label(LBoard[0][2]);
    FBoard[0][3]->label(LBoard[0][3]);
    FBoard[0][4]->label(LBoard[0][4]);
    FBoard[0][5]->label(LBoard[0][5]);
    FBoard[0][6]->label(LBoard[0][6]);
    FBoard[0][7]->label(LBoard[0][7]);


    for (int X = 0; X <= 7; ++X)
        FBoard[6][X]->label(LBoard[6][X]);
    

    FBoard[7][0] ->label(LBoard[7][0]);
    FBoard[7][1] ->label(LBoard[7][1]);
    FBoard[7][2] ->label(LBoard[7][2]);
    FBoard[7][3] ->label(LBoard[7][3]);
    FBoard[7][4] ->label(LBoard[7][4]);
    FBoard[7][5] ->label(LBoard[7][5]);
    FBoard[7][6] ->label(LBoard[7][6]);
    FBoard[7][7] ->label(LBoard[7][7]);

    for(int i=0 ; i<=7 ; i++)
    
        for(int j=0 ; j<=7 ; j++)
        
            int k=i+j;

                    if(k % 2 != 0 )
                            FBoard[i][j]->color(FL_WHITE);
                    

                    else if (k % 2 ==0 ) 
                            FBoard[i][j]->color(FL_YELLOW); 
                    
        
    
 
 void DisplayWindow::ChangeButton(Fl_Widget * o, void * v)
    DisplayWindow* Win = (DisplayWindow *) v;
    Fl_Button * NewBoard = (Fl_Button*) o;

      if (Win->flag == false)
        DisplayWindow::LastLabel =  NewBoard->label();
        NewBoard->label("  ");
        Win->flag = true;
      
      else
         NewBoard->label(DisplayWindow::LastLabel);
         Win->flag = false;

还有头文件：

class DisplayWindow: public Fl_Window 
public:

DisplayWindow(int width, int height, const char* title=0);

virtual ~DisplayWindow();

void MakeLabel();
void LabelButton();
static void ChangeButton(Fl_Button * o, void * );
static bool flag;
bool flag1;
static const char * LastLabel;

private:
Fl_Button *  FBoard[8][8];
char * LBoard[8][8];
;

#endif

【问题讨论】：

如果回调没有提供 this 作为参数，ChangeButton 怎么知道 v 是 DisplayWin？您是否尝试过运行程序以查看回调是否有效？在复制和粘贴过程中，我可能弄混了一些东西，我在下面发布了修改后的代码。回调有效，但不是我想要的，它会在单击第一个按钮时立即删除它的标签，而不是在单击第二个按钮时删除。 【参考方案1】：

cpp:

#include"Window.h"
#include"ChessBoard.h"

const char *  DisplayWindow::LastLabel;
bool   DisplayWindow::flag;
DisplayWindow::DisplayWindow(int width, int height, const char*)
:Fl_Window(800, 650, "Chess")   


                             for (int X = 0; X <= 7; ++X)
                                    for (int Y = 0; Y <= 7; ++Y)
         // Leaves all positions that arent occupied by
         // a figure at the start of the game blank
                                        FBoard[X][Y] = new Fl_Button(10 + 50*Y, 100 + 50*X, 50, 50,"");
                                        FBoard[X][Y]->callback((Fl_Callback*)DisplayWindow::ChangeButton);


            //FBoard[X][Y]->callback(ChangeButton);
                                    
                             
                             flag = false;
                             MakeLabel(); 
                             LabelButton(); 
                             show();
                          

DisplayWindow::~DisplayWindow()

void DisplayWindow::MakeLabel()

  for (int X = 0; X <= 7; ++X)
    for (int Y = 0; Y <= 7; ++Y)

            LBoard[X][Y] = ("  ");
    
  

  for (int X = 0; X <= 7; ++X) 
        LBoard[1][X] = ("WP");
    // Occupies second row with white pawns

  
    LBoard[0][0] = ("WR");
    LBoard[0][1] = ("WH");
    LBoard[0][2] = ("WB");
    LBoard[0][3] = ("WQ");
    LBoard[0][4] = ("WK");
    LBoard[0][5] = ("WB");
    LBoard[0][6] = ("WH");
    LBoard[0][7] = ("WR");


  for (int X = 0; X <= 7; ++X)
        LBoard[6][X] = ("BP");
  

    LBoard[7][0] = ("BR");
    LBoard[7][1] = ("BH");
    LBoard[7][2] = ("BB");
    LBoard[7][3] = ("BQ");
    LBoard[7][4] = ("BK");
    LBoard[7][5] = ("BB");
    LBoard[7][6] = ("BH");
    LBoard[7][7] = ("BR");


void DisplayWindow::LabelButton()

    for (int X = 0; X <= 7; ++X) 
        FBoard[1][X]->label(LBoard[1][X]);
    // Occupies second row with white pawns

    
    FBoard[0][0]->label(LBoard[0][0]);
    FBoard[0][1]->label(LBoard[0][1]);
    FBoard[0][2]->label(LBoard[0][2]);
    FBoard[0][3]->label(LBoard[0][3]);
    FBoard[0][4]->label(LBoard[0][4]);
    FBoard[0][5]->label(LBoard[0][5]);
    FBoard[0][6]->label(LBoard[0][6]);
    FBoard[0][7]->label(LBoard[0][7]);


    for (int X = 0; X <= 7; ++X)
        FBoard[6][X]->label(LBoard[6][X]);
    

    FBoard[7][0] ->label(LBoard[7][0]);
    FBoard[7][1] ->label(LBoard[7][1]);
    FBoard[7][2] ->label(LBoard[7][2]);
    FBoard[7][3] ->label(LBoard[7][3]);
    FBoard[7][4] ->label(LBoard[7][4]);
    FBoard[7][5] ->label(LBoard[7][5]);
    FBoard[7][6] ->label(LBoard[7][6]);
    FBoard[7][7] ->label(LBoard[7][7]);

    for(int i=0 ; i<=7 ; i++)
    
        for(int j=0 ; j<=7 ; j++)
        
            int k=i+j;

                    if(k % 2 != 0 )
                            FBoard[i][j]->color(FL_WHITE);
                    

                    else if (k % 2 ==0 ) 
                            FBoard[i][j]->color(FL_YELLOW); 
                    
        
    


void DisplayWindow::ChangeButton(Fl_Widget * o, void * v)
DisplayWindow* Win = (DisplayWindow *) v;
Fl_Button * NewBoard = (Fl_Button*) o;

if (Win->flag == false)
    DisplayWindow::LastLabel =  NewBoard->label();
    NewBoard->label("  ");
    Win->flag = true;

else
    NewBoard->label(DisplayWindow::LastLabel);
    Win->flag = false;

    #ifndef WINDOW_H_
#define WINDOW_H_
#include<vector>
#include<limits>
#include<string>
#include<iostream>
#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include <FL/Fl_Button.H>




class DisplayWindow: public Fl_Window 
public:

 DisplayWindow(int width, int height, const char* title=0);

virtual ~DisplayWindow();

 void MakeLabel();
 void LabelButton();
 static void ChangeButton(Fl_Widget * o, void * );
 static bool flag;
 bool flag1;
 static const char * LastLabel;
private:
 Fl_Button *  FBoard[8][8];
 char * LBoard[8][8];
;

#endif

【讨论】：

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