Xcode-缩放图像

Question

我正在尝试缩放图像，但保持宽高比。 我已经尝试过此代码，但无法正常工作：

[_malmohusEtt setClipsToBounds:YES];
[_malmohusTva setClipsToBounds:YES];
[_malmohusEtt setContentMode:UIViewContentModeScaleAspectFit];
[_malmohusTva setContentMode:UIViewContentModeScaleAspectFit];

请帮我

Answer 1

这是一个示例代码，可通过编程将图像缩放到任意尺寸，以保持宽高比。

- (UIImage*) scaleImage:(UIImage *)image toSize:(CGSize)newSize {
    CGSize scaledSize = newSize;
    float scaleFactor = 1.0;
    if( image.size.width > image.size.height ) {
        scaleFactor = image.size.width / image.size.height;
        scaledSize.width = newSize.width;
        scaledSize.height = newSize.height / scaleFactor;
    }
    else if(image.size.height > image.size.width) {
        scaleFactor = image.size.height / image.size.width;
        scaledSize.height = newSize.height;
        scaledSize.width = newSize.width / scaleFactor;
    }

    UIGraphicsBeginImageContextWithOptions( scaledSize, NO, 0.0 );
    CGRect scaledImageRect = CGRectMake( 0.0, 0.0, scaledSize.width, scaledSize.height );
    [image drawInRect:scaledImageRect];
    UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return scaledImage; }