objective-c - 屏蔽图像后UIView无法移动

Question

我有UIView一个UIImage财产。我正在掩盖该图像并将其添加到UIView. 一旦我将蒙版剪裁到图像上，我的手势就不再起作用了。

屏蔽代码：

CGContextRef ctx = UIGraphicsGetCurrentContext();
... // Creating mask
CGContextClip(ctx);
[self.image drawInRect:CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height)];
CGContextDrawPath(ctx, kCGPathStroke);

手势代码：

- (void)move:(UIPanGestureRecognizer*)gesture {  
    CGPoint translation = [gesture translationInView:self.superview];
    CGRect currentFrame = self.frame; 
    currentFrame.origin.x = self.frame.origin.x + translation.x;
    currentFrame.origin.y = self.frame.origin.y + translation.y;
    self.frame = currentFrame;
    [gesture setTranslation:CGPointZero inView:self.superview];
}

如果我删除这条线：CGContextClip(ctx);手势工作得很好。任何建议将不胜感激。