objective-c - UIScrollView 和取消缩放手势

Question

如何在 UIScrollView 上强行取消缩放打开捏合手势，比如当用户缩放“足够”远以触发新操作时？

Answer 1

要防止用户 Controller 缩放和平移但仍允许 ScrollView 的编程缩放和平移，最好的方法是覆盖 UIScrollView's - addGestureRecognizer : 子类中的方法。

-(void)addGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
{
    //Prevent any of the default panning and zooming controls from working
    gestureRecognizer.enabled = NO;
    [super addGestureRecognizer:gestureRecognizer];
    return;
}

每个手势识别器都被简单地禁用，为了更好的控制(例如允许平移控制但只允许通过双击缩放)你只需通过 -isKindOfClass: 检查传入的手势识别器。并酌情禁用。

-(void)addGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer 
{
    //Prevent zooming but not panning
    if ([gestureRecognizer isKindOfClass:[UIPinchGestureRecognizer class]]) 
    {
        gestureRecognizer.enabled = NO;
    }
    [super addGestureRecognizer:gestureRecognizer];
    return;
}

希望这对您有所帮助。