将UIButton中的图像缩放到AspectFit？

Question

我想将图像添加到UIButton,还想缩放我的图像以适应UIButton(使图像更小).请告诉我该怎么做.

这是我尝试过的,但它不起作用:

• 将图像添加到按钮并使用setContentMode:

[self.itemImageButton setImage:stretchImage forState:UIControlStateNormal];
[self.itemImageButton setContentMode:UIViewContentModeScaleAspectFit];

• 制作"拉伸图像":

UIImage *stretchImage = [updatedItem.thumbnail stretchableImageWithLeftCapWidth:0 topCapHeight:0];

Answer 1

我有同样的问题.只需设置UIButton内的ImageView的ContentMode即可.

[[self.itemImageButton imageView] setContentMode: UIViewContentModeScaleAspectFit];
[self.itemImageButton setImage:[UIImage imageNamed:stretchImage] forState:UIControlStateNormal];

希望这可以帮助.

Answer 2

这里没有任何答案对我有用,我用以下代码解决了这个问题:

button.contentMode = UIViewContentModeScaleToFill;
button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentFill;
button.contentVerticalAlignment = UIControlContentVerticalAlignmentFill;

您也可以在Interface Builder中执行此操作.

Answer 3

在宽高比适配模式下以编程方式设置UIButton imageView的最简单方法:

迅速

button.contentHorizontalAlignment = .fill
button.contentVerticalAlignment = .fill
button.imageView?.contentMode = .scaleAspectFit

Objective-C的

button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentFill;
button.contentVerticalAlignment = UIControlContentVerticalAlignmentFill;
button.imageView.contentMode = UIViewContentModeScaleAspectFit;

注意:您可以将.scaleAspectFit(UIViewContentModeScaleAspectFit)更改为.scaleAspectFill(UIViewContentModeScaleAspectFill)以设置方面填充模式

Answer 4

如果您真的想要缩放图像,请执行此操作,但在使用之前应调整大小.在运行时调整它的大小只会丢失CPU周期.

这是我用来缩放图像的类别:

的UIImage + Extra.h

@interface UIImage (Extras)
- (UIImage *)imageByScalingProportionallyToSize:(CGSize)targetSize;
@end;

的UIImage + Extra.m

@implementation UIImage (Extras)

- (UIImage *)imageByScalingProportionallyToSize:(CGSize)targetSize {

UIImage *sourceImage = self;
UIImage *newImage = nil;

CGSize imageSize = sourceImage.size;
CGFloat width = imageSize.width;
CGFloat height = imageSize.height;

CGFloat targetWidth = targetSize.width;
CGFloat targetHeight = targetSize.height;

CGFloat scaleFactor = 0.0;
CGFloat scaledWidth = targetWidth;
CGFloat scaledHeight = targetHeight;

CGPoint thumbnailPoint = CGPointMake(0.0,0.0);

if (!CGSizeEqualToSize(imageSize, targetSize)) {

        CGFloat widthFactor = targetWidth / width;
        CGFloat heightFactor = targetHeight / height;

        if (widthFactor < heightFactor) 
                scaleFactor = widthFactor;
        else
                scaleFactor = heightFactor;

        scaledWidth  = width * scaleFactor;
        scaledHeight = height * scaleFactor;

        // center the image

        if (widthFactor < heightFactor) {
                thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5; 
        } else if (widthFactor > heightFactor) {
                thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
        }
}


// this is actually the interesting part:

UIGraphicsBeginImageContextWithOptions(targetSize, NO, 0);

CGRect thumbnailRect = CGRectZero;
thumbnailRect.origin = thumbnailPoint;
thumbnailRect.size.width  = scaledWidth;
thumbnailRect.size.height = scaledHeight;

[sourceImage drawInRect:thumbnailRect];

newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

if(newImage == nil) NSLog(@"could not scale image");


return newImage ;
}

@end

您可以使用它想要的尺寸.喜欢 :

[self.itemImageButton setImage:[stretchImage imageByScalingProportionallyToSize:CGSizeMake(20,20)]];

Answer 5

我有问题图像没有按比例调整大小,所以我修复它的方式是使用边缘插入.

fooButton.contentEdgeInsets = UIEdgeInsetsMake(10, 15, 10, 15);

Answer 6

现在可以通过IB的UIButton属性来完成.关键是将图像设置为背景,否则它将无法工作.

Answer 7

扩展Dave的答案,您可以使用运行时属性在IB中设置contentMode按钮imageView全部,而无需任何代码:

• 1意思是UIViewContentModeScaleAspectFit,
• 2意思是 UIViewContentModeScaleAspectFill.

Answer 8

如果您只想减少按钮图像:

yourButton.contentMode = UIViewContentModeScaleAspectFit;
yourButton.imageEdgeInsets = UIEdgeInsetsMake(10, 10, 10, 10);

Answer 9

我有一个方法可以为我做这件事。该方法采用UIButton并使图像方面适合。

-(void)makeImageAspectFitForButton:(UIButton*)button{
    button.imageView.contentMode=UIViewContentModeScaleAspectFit;
    button.contentHorizontalAlignment=UIControlContentHorizontalAlignmentFill;
    button.contentVerticalAlignment=UIControlContentVerticalAlignmentFill;
}

Answer 10

在 xCode 13.4.1 中，配置Style为Default和State ConfigDefault

Answer 11

1-清除按钮默认文本（重要）

2-设置对齐方式如图片

3-设置内容模式（如图片）

Answer 12

雨燕5.0

 myButton2.contentMode = .scaleAspectFit
 myButton2.contentHorizontalAlignment = .fill
 myButton2.contentVerticalAlignment = .fill