自己封装的读取图片的工具 类目

#import <UIKit/UIKit.h>
typedef void(^ImageBlock) (UIImage *img);

@interface UIImage (ImageDownLoad)

+(UIImage *)imageDownLoadWithURL:(NSString *)urlString myBlock:(ImageBlock)mb;

@end

#import "UIImage+ImageDownLoad.h"

@implementation UIImage (ImageDownLoad)

+(UIImage *)imageDownLoadWithURL:(NSString *)urlString myBlock:(ImageBlock)mb{
NSURL *url=[NSURL URLWithString:urlString];
NSURLRequest *request=[NSURLRequest requestWithURL:url];
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue]completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {

UIImage *img=[UIImage imageWithData:data];
//用来图片下载完成,显示图片
mb(img);

} ];

return [UIImage imageNamed:@"87.png"];

}

@end

__weak CWViewController *weakSelf=self;
self.imv.image=[UIImage imageDownLoadWithURL:@"http://g.hiphotos.baidu.com/image/pic/item/c8ea15ce36d3d539f80e33f23987e950352ab0cb.jpg" myBlock:^(UIImage *m) {

weakSelf.imv.image=m;
}];

}