objective-c - 按下时更改按钮背景的操作，然后从一个 UIButton 再次按下时更改回来

Question

我正在为 IOS 编写类似“yahtzee”的游戏。如果我想保留那个骰子，我需要能够按下骰子（按钮），它会变成另一个图像。这很好用。我还需要能够取消选择该模具，以防我错误地选择了它。我这辈子都做不到。以下是我尝试过的众多选项中的两个：

选项1：

 - (IBAction)die1Button:(UIButton *)sender
   {
        if (sender)
        {
              if (self.die1 >= 1)
              {
                   [self.die1ButtonOutlet setBackgroundImage:([self.dieImage            
                                      dieSelectedImage:self.die1]) forState:
                                                    (UIControlStateNormal)];
                   self.die1Selected = YES;
              }
              else
              {
                   self.die1Selected = NO;
              }
        }
   }

 - (IBAction)die1ButtonSelected:(UIButton *)sender
   {
        if(sender)
        {
             if (self.die1Selected == YES)
             {
                  [self.die1ButtonOutlet setBackgroundImage:([self.dieImage 
                                             dieImage:self.die1]) forState:
                                                 (UIControlStateSelected)];
                  self.die1Selected = NO;
             }
        }

   }

选项 2：

 - (IBAction)die1Button:(UIButton *)sender
   {
        if (sender)
        {
              if (self.die1 >= 1)
              {
                   [self.die1ButtonOutlet setBackgroundImage:([self.dieImage            
                                      dieSelectedImage:self.die1]) forState:
                                                    (UIControlStateNormal)];
                   self.die1Selected = YES;
              }
              else
              {
                   self.die1Selected = NO;
              }

              if (self.die1Selected == YES)
             {
                  [self.die1ButtonOutlet setBackgroundImage:([self.dieImage 
                                             dieImage:self.die1]) forState:
                                                 (UIControlStateSelected)];
                  self.die1Selected = NO;
             }
        }
   }

第一个选项显然不起作用，也没有。出于明显的原因，第二个选项也不会让我选择任何东西。

我已经在这里和其他地方阅读了大约 30 篇关于 UIButtons 及其 IBActions 的帖子，但无法得到这个，希望有人能提供帮助。这是课堂作业，但我们鼓励从任何来源寻求帮助，只要我们没有人为我们编写整个应用程序。

Answer 1

我终于明白了，我是愚蠢的。下面是代码：

 - (IBAction)die1Button:(UIButton *)sender
 {
     if (sender)
     {
         if (self.die1Selected == NO)
         {
             self.die1Selected = YES;
             [self.die1ButtonOutlet setBackgroundImage:([self.dieImage
                    dieSelectedImage:self.die1]) forState:(UIControlStateNormal)];
         }else
         {

             [self.die1ButtonOutlet setBackgroundImage:([self.dieImage  
                    dieImage:self.die1]) forState:(UIControlStateNormal)];
             self.die1Selected = NO;
         }
     } 

 }

Answer 2

 - (IBAction)die1Button:(UIButton *)sender{
     if(self.die1Selected)
     {             
         [self.die1ButtonOutlet setBackgroundImage:([self.dieImage
                dieSelectedImage:self.die1]) forState:(UIControlStateNormal)];}
        self.die1Selected = NO;

     }else
     {

         [self.die1ButtonOutlet setBackgroundImage:([self.dieImage  
                dieImage:self.die1]) forState:(UIControlStateNormal)];
         self.die1Selected = YES;
     }
 } 

}