////  HTTPRequset.h//  请求类分装////  Created by qianfeng on 15-7-26.//  Copyright (c) 2015年 qq. All rights reserved.////通过代理和block实现函数回调,可选其一#import 
     
      #import 
      
       @class HTTPRequset;@protocol HTTPRequsetDelegate 
       
        @optional/**    进度的回调 */- (void)requestDidProgress:(CGFloat)progress;//请求完成的回调- (void)requestDidfinish:(HTTPRequset *)httprequest;/**    请求完成的回调 */- (void)requestDidError:(NSError *)error;@end/**    请求类 */@interface HTTPRequset : NSObject/**    网络请求返回数据源 */@property(nonatomic,strong) NSData * responseData;/**    字符串形式 */@property(nonatomic,copy ) NSString * reponseString;/**    代理 */@property(nonatomic,assign)id
        
         delegate;/** 使用block实现回调下载进程 */@property(nonatomic,copy) void(^requestDidProgressBlock)(CGFloat progress);/** 使用block实现回调对象 */@property(nonatomic,copy) void(^requestDidFinishBlock)(HTTPRequset * request);/** 使用block实现回调错误信息 */@property(nonatomic,copy) void(^requestDidErrorBlock)(NSError * error);/** 构造方法 */- (id)initWithUrl:(NSURL *)url;/**    开始网络请求 */- (void)startRequest;@end
        
       
      
     

////  HTTPRequset.m//  请求类分装////  Created by qianfeng on 15-7-26.//  Copyright (c) 2015年 qq. All rights reserved.//#import "HTTPRequset.h"@interface HTTPRequset ()
     
      {    NSURL * _url;    //保存下载数据    NSMutableData * _downloadData;        //总大小    long long _fileSizeBytes;}@end@implementation HTTPRequset- (id)initWithUrl:(NSURL *)url{    self = [super init];    if (self) {                _url = url;        _downloadData = [NSMutableData data];    }    return self;}- (void)startRequest{    NSURLRequest * request = [NSURLRequest requestWithURL:_url];    [NSURLConnection connectionWithRequest:request delegate:self];}#pragma mark - 代理方法- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{    //清空数据    _downloadData.length = 0;    //获取文件总大小    _fileSizeBytes = [response expectedContentLength];}- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{    //追加    [_downloadData appendData:data];    //计算进度    float progress = (float) _downloadData.length / _fileSizeBytes;    if ([self.delegate respondsToSelector:@selector(requestDidProgress:)]) {        [self.delegate requestDidProgress:progress];    }    self.requestDidProgressBlock(progress);    }- (void)connectionDidFinishLoading:(NSURLConnection *)connection{    //请求取消    [connection cancel];        //    _responseData = _downloadData;    _reponseString = [[NSString alloc]initWithData:_downloadData encoding:NSUTF8StringEncoding];    self.requestDidFinishBlock(self);    if ([self.delegate respondsToSelector:@selector(requestDidfinish:)]) {        [self.delegate requestDidfinish:self];    }            }- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{    //请求取消    [connection cancel];    self.requestDidErrorBlock(error);    if ([self.delegate respondsToSelector:@selector(requestDidError:)]) {        [self.delegate requestDidError:error];    }    }@end