按下其他按钮后无法更改uibutton的图像

Question

我有2个按钮，即使它们被释放，它们也与按下的图像保持一致，直到按下另一个按钮，然后图像恢复为正常图像，我的代码是这样的：

    - (IBAction)button1_touch:(UIButton *)sender
{

    [Button2 setImage:[UIImage imageNamed:@"b2Released.png"] forState:UIControlStateNormal];

    [Button1 setImage:[UIImage imageNamed:@"b1Pressed.png"] forState:UIControlStateNormal];    
}

- (IBAction)button2_touch:(UIButton *)sender
{
    [Button1 setImage:[UIImage imageNamed:@"b1Released.png"] forState:UIControlStateNormal];

    [Button2 setImage:[UIImage imageNamed:@"b2Pressed.png"] forState:UIControlStateNormal]; 


}

上面的代码在应用程序启动时工作正常，行为是预期的同时按下两个按钮，图像正确更改，但是当我按下除这两个按钮之外的其他按钮时，“ Button2”一旦获得“ B2Pressed.png”图像，就永远不会返回其释放的图像，我在button1_touch中编写了一个nslog，并按预期进行打印，而Button1得到了其按下的图像，但是Button2没有得到其释放的图像，就像当我按下其他按钮时UiButton的setImage方法损坏按钮比这两个按钮更重要，其他按钮则与那两个按钮无关，对我来说，这种行为完全没有意义，是否会破坏xcode？ 我正在使用xcode 7.2

编辑：仅当该按钮具有分配给它的操作选择器（UIControlEventTouchUpInside）时，才出现该问题。

Answer 1

为此，可以使用UIButton的selected状态：

- (void)viewDidLoad {
    // ...
    // the place where you do buttons setup
    [button1 setImage:[UIImage imageNamed:@"b1Released"] forState:UIControlStateNormal];
    [button1 setImage:[UIImage imageNamed:@"b1Pressed"] forState:UIControlStateSelected];
    [button2 setImage:[UIImage imageNamed:@"b2Released"] forState:UIControlStateNormal];
    [button2 setImage:[UIImage imageNamed:@"b2Pressed"] forState:UIControlStateSelected];
}    

- (IBAction)firstButtonTouch:(UIButton *)sender {
    button1.selected = YES;
    button2.selected = NO;
}

- (IBAction)secondButtonTouch:(UIButton *)sender {
    button1.selected = NO;
    button2.selected = YES;
}