iphone – 如何检查UILabel文本是否被触动？

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [[event allTouches] anyObject];
    if (CGRectContainsPoint([self.currentLetter frame],[touch LOCATIOnInView:self.view]))
    {
        NSLog(@"HIT!");
    }
}

根据我的理解,问题是检测在UILabel中组成文本的字形之间发生点击(触摸)的时间.如果触摸位于任何字形的路径之外,则不计入.

这是我的解决方案它假定一个名为_label的UILabel * ivar和一个与包含标签的视图关联的UITapGestureRecognizer.

- (IBACtion) onTouch: (UITapGestureRecognizer*) tgr
{
    CGPoint p = [tgr LOCATIOnInView: _label];

    // in case the BACkground of the label isn't transparent...
    UIColor* labelBACkgroundColor = _label.BACkgroundColor;
    _label.BACkgroundColor = [UIColor clearColor];

    // get a UIImage of the label
    UIGraphicsBeginImageContext( _label.bounds.size );
    CGContextRef c = UIGraphicsGetCurrentContext();
    [_label.layer renderInContext: c];
    UIImage* i = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    // restore the label's BACkground...
    _label.BACkgroundColor = labelBACkgroundColor;

    // draw the pixel we'rE interested in into a 1x1 bitmap
    unsigned char pixel = 0x00;
    c = CGBitmapContextCreate(&pixel,1,8,NULL,kCGImageAlphaOnly);
    UIGraphicsPushContext(c);
    [i drawAtPoint: CGPointMake(-p.x,-p.y)];
    UIGraphicsPopContext();
    CGContextRelease(c);

    if ( pixel != 0 )
    {
        NSLog( @"touched text" );
    }
}