Objective C - 设置 ImageView 宽度并保持纵横比

Question

我正在使用以下动画在视图上显示缩略图的全屏图像：

[UIView animateWithDuration:0.5 delay:0 options:0 animations:^{

            [testImageView setFrame:CGRectMake(0, 0, testImage.size.width, testImage.size.height)];

        }completion:^(BOOL finished){

}];

但是，如果是大图，则不会包含屏幕边界内的图像。

有什么方法可以将图片的宽度设置为屏幕的宽度，然后调整图片的高度，以保持适当的纵横比？

Answer 1

CGRect bounds = [UIScreen mainScreen].bounds;
[testImageView setFrame:bounds];
testImageView.contentMode = UIViewContentModeScaleAspectFit;

但是如果图像的比例不等于屏幕可能会有一些填充's.If您希望图像覆盖整个屏幕，然后将 contentMode 更改为 UIViewContentModeScaleAspectFill。

Answer 2

与上述方法类似，但有更多修改：

CGFloat verticalScale = image.height / bounds.height;
CGFloat horizontalScale = image.width / bounds.width;
CGFloat scale = max(verticalScale,horizontalScale);
CGFloat imageViewHeight = image.height / scale;
CGFloat imageViewWidth = image.width / scale;
CGRect imageViewFrame = CGRectMake(x: DESIRE_X, y: DESIRE_Y, width:imageViewWidth ,height:imageViewHeight)
imageView.frame = imageViewFrame;
imageView.contentMode = UIViewContentModeScaleAspectFill;

Answer 3

请尝试以下代码：

testImageView 
    =[[UIImageView alloc]initWithFrame:CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y ,self.view.frame.size.width, self.view.frame.size.height
    )]

Objective C - 设置 ImageView 宽度并保持纵横比

Objective C - Set ImageView Width and Maintain Aspect Ratio

objective-c

uiimageview

uiimage

ios