iphone - UIButton 的 BackgroundImage 有时不会随着 touchUpInside 事件而改变

Question

UIButton设置为以下代码：

UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 27, 27)];
[btn setBackgroundImage:[UIImage imageNamed:@"imgUp.png"] forState:UIControlStateNormal];
[btn setBackgroundImage:[UIImage imageNamed:@"imgDown.png"] forState:UIControlStateHighlighted];
[btn addTarget:self action:@selector(btnPressed:) forControlEvents:UIControlEventTouchUpInside];

btw如果我快速触摸，imgDown.png则不会出现，但btnPressed:会触发动作。怎么可能修好？任何帮助表示赞赏:)

Answer 1

在您的代码中添加这一行：

[btn setBackgroundImage:[UIImage imageNamed:@"imgDown.png"] forState:UIControlStateSelected];

Answer 2

您应该为 btnPressed: 函数内的按钮 (btn) 调用 setHiglighted: 方法。

Answer 3

它工作正常我会测试它请检查你的图像并尝试它：

UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 27, 27)];
[button setBackgroundImage:[UIImage imageNamed:@"rainy.jpg"] forState:UIControlStateNormal];
[button setBackgroundImage:[UIImage imageNamed:@"Icon.png"] forState:UIControlStateHighlighted];
[button addTarget:self action:@selector(btnPressed:) forControlEvents:UIControlEventTouchUpInside];
[self.view button];

Answer 4

下面的代码可以解决问题。

-(void)btnPressedDelay{

    //original code in btnPressed: method
}

- (void) btnPressed:(id)sender
{    

    [self performSelector:@selector(btnPressedDelay) withObject:nil afterDelay:0];
// 0 did the magic here

}