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