在UIScrollView中缩放UIImageView超出范围

Question

我已成功实现了UIImageView中UIScrollView的缩放，但我遇到了一个令我恼火的奇怪问题。

基本上，当我放大图像时

我可以平移视图以实际滚动出图像边框，我留下了这样的黑色区域：

随着我放大更多，我可以让黑色边框填满整个屏幕！ 同时在iPhone Photo应用程序中，您无法缩小实际图像。我的实施中有什么问题？

看起来像这样：

UIImage *imageToDisplay = [UIImage imageWithData:tmpImageData];
imageViewMain.image = imageToDisplay;
imageViewMain.frame = CGRectMake(0, 0, scrollViewMain.frame.size.width, scrollViewMain.frame.size.height);
imageViewMain.contentMode = UIViewContentModeScaleAspectFit;

scrollViewMain.delegate = self;
scrollViewMain.minimumZoomScale = 1.0;
scrollViewMain.maximumZoomScale = 9.0;
scrollViewMain.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
scrollViewMain.contentSize = imageViewMain.frame.size;

[self.view addSubview:scrollViewMain];
[scrollViewMain addSubview:imageViewMain];

我也实现了这个方法：

- (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return imageViewMain;
}

提前致谢！

编辑： 当我第一次加载视图时，我收缩了我的UIImageView以适应滚动视图，图像看起来像这样：

Answer 1

试试这段代码....在需要的地方更改一些代码...对UIPinchGestureRecognizer使用UIImageView，然后在UIScrollView中添加此图片，如下所示.. < / p>

UIImageView *img = [[UIImageView alloc]init];
img.image = [UIImage imageWithData:tmpImageData];
img.userInteractionEnabled = YES;
img.frame = CGRectMake(210,100, 200, 200);/// define frame which you want...
[img sizeToFit];

UIPinchGestureRecognizer *pinchRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(scale:)];
[pinchRecognizer setDelegate:self];
[img addGestureRecognizer:pinchRecognizer];
[pinchRecognizer release];
[scrollViewMain addSubview:img];
[scrollViewMain bringSubviewToFront:img];
[img release]; 

然后将此下方代码粘贴到.m文件中......

#pragma mark GestureRecognizer Methods
-(void)scale:(id)sender 
{
    UIView *imgTempGest = [sender view];
    if([(UIPinchGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) 
    {
        lastScale = 1.0;
        return;
    }
    CGFloat scale = 1.0 - (lastScale - [(UIPinchGestureRecognizer*)sender scale]);

    CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
    CGAffineTransform newTransform = CGAffineTransformScale(currentTransform, scale, scale);

    [[(UIPinchGestureRecognizer*)sender view] setTransform:newTransform];

    [imgTempGest setTransform:newTransform];

    lastScale = [(UIPinchGestureRecognizer*)sender scale];
}

这里对于LastScale，只需在.h文件中定义该变量，如下文...

CGFloat lastScale;

我希望这对你有帮助......

Answer 2

原始图片是否包含顶部和底部的边框？如果实际图像包含黑色顶部和底部黑色区域，则可以在那里使用相同的代码，输出没有错误。并添加此代码，

  

scrollView.scrollEnabled = YES

也改变了，

  

scrollView.contentSize = imageView.bounds.size;

此外，您提供的缩放比例为9.您还需要多少？将其更改为3或4并尝试。您的问题将得到解决