iOS - 双击uibutton

Question

我有一个按钮,我正在测试它上面的水龙头,一个水龙头就可以改变背景颜色,两个水龙头可以换另一种颜色,三个水龙头再次点亮另一种颜色.代码是:

- (IBAction) button 
{
    UITapGestureRecognizer *tapOnce = [[UITapGestureRecognizer alloc] initWithTarget:self  action:@selector(tapOnce:)];
    UITapGestureRecognizer *tapTwice = [[UITapGestureRecognizer alloc] initWithTarget:self  action:@selector(tapTwice:)];
    UITapGestureRecognizer *tapTrice = [[UITapGestureRecognizer alloc] initWithTarget:self  action:@selector(tapTrice:)];

    tapOnce.numberOfTapsRequired  = 1;
    tapTwice.numberOfTapsRequired = 2;
    tapTrice.numberOfTapsRequired = 3;

    //stops tapOnce from overriding tapTwice
    [tapOnce requireGestureRecognizerToFail:tapTwice];
    [tapTwice requireGestureRecognizerToFail:tapTrice];

    //then need to add the gesture recogniser to a view - this will be the view that recognises the gesture
    [self.view addGestureRecognizer:tapOnce];
    [self.view addGestureRecognizer:tapTwice];
    [self.view addGestureRecognizer:tapTrice];
}

- (void)tapOnce:(UIGestureRecognizer *)gesture
{ 
    self.view.backgroundColor = [UIColor redColor]; 
}

- (void)tapTwice:(UIGestureRecognizer *)gesture
{
    self.view.backgroundColor = [UIColor blackColor];
}

- (void)tapTrice:(UIGestureRecognizer *)gesture
{
    self.view.backgroundColor = [UIColor yellowColor]; 
}

问题是第一次点击不起作用,另一种是.如果我使用没有按钮的代码,它可以很好地工作.谢谢.

Answer 1

如果您希望在点按按钮时更改颜色,则应在viewDidLoad方法中按钮上添加这些手势,而不是按相同的按钮操作.上面的代码将重复添加按钮的手势,self.view而不是button.

- (void)viewDidLoad {
      [super viewDidLoad];
      UITapGestureRecognizer *tapOnce = [[UITapGestureRecognizer alloc] initWithTarget:self  action:@selector(tapOnce:)];
      UITapGestureRecognizer *tapTwice = [[UITapGestureRecognizer alloc] initWithTarget:self  action:@selector(tapTwice:)];
      UITapGestureRecognizer *tapTrice = [[UITapGestureRecognizer alloc] initWithTarget:self  action:@selector(tapTrice:)];

      tapOnce.numberOfTapsRequired = 1;
      tapTwice.numberOfTapsRequired = 2;
      tapTrice.numberOfTapsRequired = 3;
      //stops tapOnce from overriding tapTwice
      [tapOnce requireGestureRecognizerToFail:tapTwice];
      [tapTwice requireGestureRecognizerToFail:tapTrice];

      //then need to add the gesture recogniser to a view - this will be the view that recognises the gesture
      [self.button addGestureRecognizer:tapOnce]; //remove the other button action which calls method `button`
      [self.button addGestureRecognizer:tapTwice];
      [self.button addGestureRecognizer:tapTrice];
}