使用SDWebImage淡入淡出的方式加载图片

效果：

请通过以下方式下载源码：

找到它修改文件的地方：

以下是使用源码：

//
//  ViewController.m
//  SDWebImageFade
//
//  Created by YouXianMing on 14-10-5.
//  Copyright (c) 2014年 YouXianMing. All rights reserved.
//

#import "ViewController.h"
#import "UIImageView+WebCache.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    NSString *picUrl = @"http://th04.deviantart.net/fs70/PRE/i/2014/277/4/b/cheetahr_by_harpiya-d81l8iv.jpg";

    UIImageView *imageView = [[UIImageView alloc] initWithFrame:self.view.bounds];
    [self.view addSubview:imageView];

    [imageView setImageWithURL:[NSURL URLWithString:picUrl]
              placeholderImage:nil
                       options:SDWebImageCacheMemoryOnly
                      progress:^(NSInteger receivedSize, NSInteger expectedSize) {
                          NSLog(@"%.2f", (float)receivedSize / (float)expectedSize);
                      }
                     completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType) {

                     }];
}

@end

以下是需要注意的地方