矩形圖像縮放到適合的方面廣場，MPMediaItemArtwork

Question

MPMediaItemArtwork *albumArt = [[MPMediaItemArtwork alloc] initWithImage:image]]; 

使用我有一個UIImage是rectangle，它的裁剪，當我把它MPNowPlayingInfoCenter使用MPMediaItemArtwork方。我如何根據寬度調整UIImage以適合square UIImage並將剩餘空白留空？

Answer 1

把UIImage爲UIImageView，設置contentMode爲UIImageView是UIViewContentModeScaleAspectFit，並使其回到UIImage。

+ (UIImage *)imageToSquare:(UIImage *)image byWidth:(float)width{ 
     UIImageView *view = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, width, width)]; 
     [view setImage:image]; 
     view.contentMode = UIViewContentModeScaleAspectFit; 

     UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque, 0.0); 
     [view.layer renderInContext:UIGraphicsGetCurrentContext()]; 

     UIImage * img = UIGraphicsGetImageFromCurrentImageContext(); 

     UIGraphicsEndImageContext(); 

     return img; 
    }