Question

我有一个UITextView，我想检测一下。

看起来我可以简单地覆盖touchesEnded:withEvent并检查[[touches anyObject] tapCount] == 1，但是这个事件甚至不会触发。

如果我覆盖这样的4个事件：

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    NSLog(@"touchesBegan (tapCount:%d)", touch.tapCount);
    [super touchesBegan:touches withEvent:event];
}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
        NSLog(@"touches moved");
}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    NSLog(@"touchesEnded (tapCount:%d)", touch.tapCount);
        [super touchesEnded:touches withEvent:event];
}

-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
        NSLog(@"touches cancelled");
}

我得到这样的输出：

> touchesBegan (tapCount:1)
> touchesCancelled 
> touchesBegan (tapCount:1) 
> touches moved 
> touches moved
> touches moved 
> touchesCancelled

似乎我从来没有得到touchesEnded事件。

有什么想法吗？

Answer 1

更新：我最终在这里使用了这个技术： https://devforums.apple.com/message/94569#94569

我不确定这是不是一个bug，但是UITextView确实需要利用触摸事件来进行复制和弹出菜单。粘贴3.0，这样就可以解释为什么它会吞下这个事件。

如果你问我，那就太蹩脚了。

更新：我在这里写了博客：http://benscheirman.com/2009/07/detecting-a-tap-on-a-uitextview

Answer 2

我将这样的UITextview子类化，即使使用IOS 5.0.1，它似乎也可以工作。关键是要覆盖touchesBegan，而不仅仅是touchesEnded（这是我真正感兴趣的）。

@implementation MyTextView


- (id)initWithFrame:(CGRect)frame {
    return [super initWithFrame:frame];
}

- (void) touchesBegan: (NSSet *) touches withEvent: (UIEvent *) event { 
    // If not dragging, send event to next responder
    if (!self.dragging) 
        [self.nextResponder touchesBegan: touches withEvent:event]; 
    else
        [super touchesBegan: touches withEvent: event];
}

- (void) touchesEnded: (NSSet *) touches withEvent: (UIEvent *) event { 
    // If not dragging, send event to next responder
    if (!self.dragging) 
        [self.nextResponder touchesEnded: touches withEvent:event]; 
    else
        [super touchesEnded: touches withEvent: event];
}

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
    if (action == @selector(paste:))
        return NO;
    if (action == @selector(copy:))
        return NO;
    if (action == @selector(cut:))
        return NO;
    if (action == @selector(select:))
        return NO;
    if (action == @selector(selectAll:))
        return NO;
    return [super canPerformAction:action withSender:sender];
}

- (BOOL)canBecomeFirstResponder {
    return NO;
}

- (void)dealloc {
    [super dealloc];
}

Answer 3

您可以通过覆盖canPerformAction:withSender:方法关闭剪切/复制/粘贴，这样您就可以为所有不想允许的操作返回NO。

请参阅UIResponder documentation ...

希望这会阻止你被吃掉。

UITextView触摸事件未触发

3 个答案: