NSURLConnection异步发送HTTP请求

最新推荐文章于 2020-05-08 13:22:25 发布

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本文介绍如何使用NSURLConnection在iOS应用中实现异步HTTP GET请求。具体包括构造请求URL、设置请求参数、发起请求及处理响应数据等关键步骤。

NSURLConnection异步发送HTTP请求

- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
{
NSString *new = [searchBar.text stringByReplacingOccurrencesOfString:@" " withString:@"+"];
NSString *urlString = [NSString stringWithFormat:@"http://192.168.1.104/test.php?cid=%@",new];
NSStringEncoding enc = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);
  NSString *strUrld8 = [urlString stringByAddingPercentEscapesUsingEncoding:enc];
//调用http get请求方法
[self sendRequestByGet:strUrld8];
}
//HTTP get请求方法
- (void)sendRequestByGet:(NSString*)urlString
{
NSURL *url=[NSURL URLWithString:urlString];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url
                cachePolicy:NSURLRequestReloadIgnoringLocalCacheData
               timeoutInterval:60];
//设置请求方式为get
[request setHTTPMethod:@"GET"];
//添加用户会话id
[request addValue:@"text/html" forHTTPHeaderField:@"Content-Type"];
//连接发送请求
receivedData=[[NSMutableData alloc] initWithData:nil];
NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];
[request release];
[conn release];
}
- (void)connection:(NSURLConnection *)aConn didReceiveResponse:(NSURLResponse *)response {
    // 注意这里将NSURLResponse对象转换成NSHTTPURLResponse对象才能去
    NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse*)response;
    if ([response respondsToSelector:@selector(allHeaderFields)]) {
        NSDictionary *dictionary = [httpResponse allHeaderFields];
        NSLog(@"[email=dictionary=%@]dictionary=%@",[dictionary[/email] description]);

    }
}
//接收NSData数据
- (void)connection:(NSURLConnection *)aConn didReceiveData:(NSData *)data {
[receivedData appendData:data];
}
- (void)connection:(NSURLConnection *)aConn didFailWithError:(NSError *)error{
NSLog(@"[email=error=%@]error=%@",[error[/email] localizedDescription]);
}
//接收完毕,显示结果
- (void)connectionDidFinishLoading:(NSURLConnection *)aConn {
   NSString *results = [[NSString alloc]
                         initWithBytes:[receivedData bytes]
                         length:[receivedData length]
                         encoding:NSUTF8StringEncoding];

[self writeToFile:receivedData];
NSLog(@"results=%@",results);
}

//接收的数据写入文件
-(void)writeToFile:(NSData *)data{
    NSString *filePath=[NSString stringWithFormat:@"%@",_fileName];
    if([[NSFileManager defaultManager] fileExistsAtPath:filePath] == NO){
        [[NSFileManager defaultManager] createFileAtPath:filePath contents:nil attributes:nil];
    }
    FILE *file = fopen([_fileName UTF8String], [@"ab+" UTF8String]);
    int readSize = [data length];
    fwrite((const void *)[data bytes], readSize, 1, file);
    fclose(file);
}