3种图片拉伸不变化的方法

方法都会返回一张新的图片需要来接受返回的新图片
    
    UIImage *image = [UIImage imageNamed:@"searchbar_textfield_background”];
                      
    方法一
                      
    searchBar.background = [image resizableImageWithCapInsets:UIEdgeInsetsMake(image.size.height * 0.5, image.size.width *0.5, image.size.height * 0.5, image.size.width * 0.5)];
                      
                      
    方法二
    searchBar.background = [image resizableImageWithCapInsets:UIEdgeInsetsMake(image.size.height * 0.5, image.size.width *0.5, image.size.height * 0.5, image.size.width * 0.5) resizingMode:UIImageResizingModeTile];
                      
    方法三
    searchBar.background = [image stretchableImageWithLeftCapWidth:image.size.width *0.5 topCapHeight:image.size.height *0.5];