iOS中使用block进行网络请求回调 - xuym

//
//  HttpRequest.h
//  UseBlockCallBack
//
//  Created by Michael on 2/13/14.
//  Copyright (c) 2014 EIMS. All rights reserved.
//

#import <Foundation/Foundation.h>

typedef void (^FinishBlock)(NSString *dataString);

@interface HttpRequest : NSObject<NSURLConnectionDataDelegate>

@property (strong, nonatomic) NSMutableData *resultData;
@property (strong, nonatomic) FinishBlock finishBlock;

+ (void)postRequestWithURL:(NSString *)urlStr
paramters:(NSString *)paramters
finshedBlock:(FinishBlock)block;

@end

//
//  HttpRequest.m
//  UseBlockCallBack
//
//  Created by Michael on 2/13/14.
//  Copyright (c) 2014 EIMS. All rights reserved.
//

#import "HttpRequest.h"

@implementation HttpRequest

+ (void)postRequestWithURL:(NSString *)urlStr
paramters:(NSString *)paramters
finshedBlock:(FinishBlock)block
{
HttpRequest *httpRequest = [[HttpRequest alloc]init];
httpRequest.finishBlock = block;

NSURL *url = [NSURL URLWithString:urlStr];
NSMutableURLRequest *requset = [[NSMutableURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:30];
[requset setHTTPBody:[paramters dataUsingEncoding:NSUTF8StringEncoding]];

NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:requset delegate:httpRequest];
NSLog(connection ? @"连接创建成功" : @"连接创建失败");
}
/**
*  接收到服务器回应的时回调
*/
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;
if (!self.resultData) {
self.resultData = [[NSMutableData alloc]init];
} else {
[self.resultData setLength:0];
}

if ([response respondsToSelector:@selector(allHeaderFields)]) {
NSDictionary *dic = [httpResponse allHeaderFields];
NSLog(@"[network]allHeaderFields:%@",[dic description]);
}
}
/**
*  接收到服务器传输数据的时候调用，此方法根据数据大小执行若干次
*/
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[self.resultData appendData:data];
}
/**
*  数据传完之后调用此方法
*/
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSString *resultStr = [[NSString alloc]initWithData:self.resultData
encoding:NSUTF8StringEncoding];
if (self.finishBlock) {
self.finishBlock(resultStr);
}
}
/**
*  网络请求过程中，出现任何错误（断网，连接超时等）会进入此方法
*/
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
NSLog(@"network error : %@", [error localizedDescription]);

if (self.finishBlock) {
self.finishBlock(nil);
}
}

@end

[HttpRequest postRequestWithURL:@"http://www.baidu.com"
paramters:@""
finshedBlock:^(NSString *dataString) {
NSLog(@"finish callback block, result: %@", dataString);
}];