强大的HTTP包装开源项目ASIHTTPRequest介绍

ASIHTTPRequest 是一个直接在CFNetwork上做的开源项目，提供了一个比官方更方便更强大的HTTP网络传输的封装。它的特色功能如下：
1，下载的数据直接保存到内存或文件系统里
2，提供直接提交(HTTP POST)文件的API
3，可以直接访问与修改HTTP请求与响应HEADER
4，轻松获取上传与下载的进度信息
5，异步请求与队列，自动管理上传与下载队列管理机
6，认证与授权的支持
7，Cookie
8，请求与响应的GZIP
9，代理请求

 下面来两个ASIHTTPRequest的小例子：

NSURL *url = [NSURL URLWithString:@"http://www.baidu.com"];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request start];
NSError *error = [request error];
if (!error) {
    NSString *response = [request responseString];
}

  当你需要添加更多的请求信息时，如，添加个请求Header：
[request addRequestHeader:@"name" value:@"Jory lee"];

  添加Post请求时的健值:
[request setPostValue:@"Ben" forKey:@"first_name"];
[request setPostValue:@"Copsey" forKey:@"last_name"];
[request setFile:@"/Users/ben/Desktop/ben.jpg" forKey:@"photo"];

  设置HTTP的授权帐号：
[request setUsername:@"username"];
[request setPassword:@"password"];

  一个异步请求：
- (IBAction)grabURLInBackground:(id)sender
{
NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDelegate:self];
[request startAsynchronous];
}

- (void)requestFinished:(ASIHTTPRequest *)request
{
// Use when fetching text data
NSString *responseString = [request responseString];

// Use when fetching binary data
NSData *responseData = [request responseData];
}

- (void)requestFailed:(ASIHTTPRequest *)request
{
NSError *error = [request error];
}  

  在我们数据获取的过程中，如果数据源复杂，一个请求队列是必不可少的：
- (IBAction)grabURLInTheBackground:(id)sender
{
if (![self queue]) {
[self setQueue:[[[NSOperationQueue alloc] init] autorelease]];
}

NSURL *url = [NSURL URLWithString:@"http://allseeing-i.com"];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDelegate:self];
[request setDidFinishSelector:@selector(requestDone:)];
[request setDidFailSelector:@selector(requestWentWrong:)];
[[self queue] addOperation:request]; //queue is an NSOperationQueue
}

- (void)requestDone:(ASIHTTPRequest *)request
{
NSString *response = [request responseString];
}

- (void)requestWentWrong:(ASIHTTPRequest *)request
{
NSError *error = [request error];
}  

  另外大家可以通过下面这个代码例子，看 ASIHTTP 比传统的 post 方法的方便之处

post用法
    NSString *post = @"这里放要传递的参数";   
    NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];   
    
    NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];   
    
    NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];   
    [request setURL:[NSURL URLWithString:@"请求地址"]];   
    [request setHTTPMethod:@"POST"];   
    [request setValue:postLength forHTTPHeaderField:@"Content-Length"]; 
    //[request addValue:@"gzip" forHTTPHeaderField:@"Accepts-Encoding"];
    [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];   
    [request setHTTPBody:postData];   

    NSURLConnection *conn=[[NSURLConnection alloc] initWithRequest:request delegate:self];  
    
    if (conn)    
    {   
        receivedbData = [[NSMutableData data] retain];   
    }    
    else    
    {   
        // inform the user that the download could not be made   
    } 

ASIHTTP 方法

NSURL *url = [NSURL URLWithString:@"请求地址"];
//ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
ASIFormDataRequest *request=[ASIFormDataRequest requestWithURL:url];
[request setPostValue:@"值" forKey:@"参数1"];
[request setPostValue:@"值" forKey:@"参数2"];

[request start];
NSError *error = [request error];
if (!error) {
NSString *response = [request responseString];
NSLog(response);
}

相比之下，ASIHTTP 的确省了很多代码。更多信息请访问官方网站 http://allseeing-i.com/