当图像在 UIScrollView 内旋转时保持缩放比例

Question

我在 ScrollView 中有一个图像。它允许捏合和缩放。还可以将 ScrollView 内的图像旋转到自定义角度。当我这样做时，我会丢失图像的当前缩放级别，并且它会恢复到 100% 缩放并旋转。有没有办法在旋转图像时保持缩放级别？

我现在正在这样做：

    UIScrollView* mainScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 80, 
                            self.view.frame.size.width, self.view.frame.size.height   )];

   self.pictureView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"Image1.png"]];

    [mainScrollView setContentSize:CGSizeMake//(620,612)];
     (self.pictureView.frame.size.width, self.pictureView.frame.size.height)];
    [mainScrollView addSubview:self.pictureView];
    mainScrollView.minimumZoomScale = 0.5;
    mainScrollView.maximumZoomScale = 6.0;
    mainScrollView.delegate = self;   
    [mainScrollView setScrollEnabled:YES];
    [self.view addSubview:mainScrollView];
    [mainScrollView release];


-(void) rotatePicture:(float) value{
 self.pictureView.transform = CGAffineTransformMakeRotation(value );
}

Answer 1

您尝试过吗：

-(void) rotatePicture:(float) value{
     self.pictureView.transform = CGAffineTransform CGAffineTransformRotate (self.pictureView.transform, value);
}

它的作用是保留图片视图上的缩放变换，并在其顶部添加旋转。