Question

我需要在点击时将UIButton图像更改为“选定”或“突出显示”状态的图像（而不是点按结束时）。

此外，我需要使用以下代码将按钮的状态更改为“已选择”：

- (IBAction)convertDown:(id)sender {
    [buttonConvert setSelected:TRUE];
}

但是使用这段代码，我会看到“正常”状态的图像，直到敲击结束:(

如何解决这个问题？

Answer 1

这是Interface Builder问题。在敲击结束前的那段时间内无法设置图像。可以通过以下代码修复：

- (void)viewDidLoad {
    [super viewDidLoad];
    [buttonConvert setBackgroundImage:[UIImage imageNamed:@"iphone_button_highlighted.png"] 
        forState:UIControlStateSelected | UIControlStateHighlighted];
}

Answer 2

为按钮ControlEvents

分配不同的目标

有许多ControlEvents可用：

   UIControlEventTouchDown           = 1 <<  0,
   UIControlEventTouchDownRepeat     = 1 <<  1,
   UIControlEventTouchDragInside     = 1 <<  2,
   UIControlEventTouchDragOutside    = 1 <<  3,
   UIControlEventTouchDragEnter      = 1 <<  4,
   UIControlEventTouchDragExit       = 1 <<  5,
   UIControlEventTouchUpInside       = 1 <<  6,
   UIControlEventTouchUpOutside      = 1 <<  7,
   UIControlEventTouchCancel         = 1 <<  8,

   UIControlEventValueChanged        = 1 << 12,

   UIControlEventEditingDidBegin     = 1 << 16,
   UIControlEventEditingChanged      = 1 << 17,
   UIControlEventEditingDidEnd       = 1 << 18,
   UIControlEventEditingDidEndOnExit = 1 << 19,

   UIControlEventAllTouchEvents      = 0x00000FFF,
   UIControlEventAllEditingEvents    = 0x000F0000,
   UIControlEventApplicationReserved = 0x0F000000,
   UIControlEventSystemReserved      = 0xF0000000,
   UIControlEventAllEvents           = 0xFFFFFFFF

示例：

[yourButton addTarget:self action:@selector(methodTouchUpInside:) forControlEvents: UIControlEventTouchUpInside]; - (void)methodTouchDown:(id)sender{ NSLog(@"TouchDown"); }

或添加gustures而不是为ControlEvents分配目标

UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)]; [yourButton addGestureRecognizer: tapGesture]; - (void) handleTap:(UITapGestureRecognizer *)sender { if(sender.state == UIGestureRecognizerStateBegan) { NSLog(@"UIGestureRecognizerStateBegan"); } else if(sender.state == UIGestureRecognizerStateEnded) { NSLog(@"UIGestureRecognizerStateEnded"); } }

有许多UIGestureRecognizerState可用。

UIGestureRecognizerStatePossible, UIGestureRecognizerStateBegan, UIGestureRecognizerStateChanged, UIGestureRecognizerStateEnded, UIGestureRecognizerStateCancelled, UIGestureRecognizerStateFailed, UIGestureRecognizerStateRecognized

如何更改按钮状态时更改UIButton的图像？

2 个答案: