iOS：仅使用多点触控缩放uiscrollview

Question

我有以下代码：

[scrollView setMinimumZoomScale:1.00];
[scrollView setMaximumZoomScale:2.00];
scrollView.delegate=self;

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

   NSSet *allTouches = [event allTouches];
    if ([allTouches count] == 2) {

        NSLog(@"multitouch");
        zoomMultiTouch = TRUE;


    }

     else if ([allTouches count] == 1){

        NSLog(@"single touch");
        zoomMultiTouch = FALSE;
    }

     else return;

}


- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {


    if (zoomMultiTouch){
        scrollView.userInteractionEnabled = YES;
        scrollView.scrollEnabled = YES;
        NSLog(@"zoomMultitouch moved");
    }

    else {
        scrollView.userInteractionEnabled = NO;
        scrollView.scrollEnabled = NO;
        NSLog(@"NOzoom moved");
    }

  //some code for coloring an image

}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    scrollView.userInteractionEnabled = NO;
    scrollView.scrollEnabled = NO;
    zoomMultiTouch = FALSE;
}

如您所见，我想用内部图像缩放scrollView； 当我用手指触摸scrollView时，我给图像着色，而不是当我用两根手指触摸scrollview时，我想对其进行缩放，并且如果我用手指触摸，则必须禁用zomm。 用我的代码不会发生； 它可以识别两次触摸但无法激活变焦，为什么？

Answer 1

我认为问题在于您没有实现缩放所需的所有委托方法。

 The UIScrollView class can have a delegate that must adopt the UIScrollViewDelegate protocol. For zooming and panning to work, the delegate must implement both viewForZoomingInScrollView: and scrollViewDidEndZooming:withView:atScale:; in addition, the maximum (maximumZoomScale) and minimum ( minimumZoomScale) zoom scale must be different. 

希望能帮助到你。

UIScrollView类参考