iPhone URL 读取操作

操作类

NSURL 

NSURLRequest  与  NSURLResponse 

NSURLConnection : 同步存取和异步存取

异步存取实例：

// 发送URL

NSString *url = [[NSString alloc] initWithFormat:@"http://www.***.com"]; 

// 发送参数

NSString *postMsg = [NSString stringWithFormat:@"uid=admin&pwd=123456"];

NSData *postData = [postMsg dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];

NSString *postLength = [NSString stringWithFormat:@"%d",[postData length]];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:url]];
[request setHTTPMethod:@"POST"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody:postData];

NSMutableData *_data = [[NSMutableData alloc] initWithLength:0];

NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
// 收到响应时, 会触发
- (void)connection:(NSURLConnection *)aConnection didReceiveResponse:(NSURLResponse *)aResponse;

// 你可以在里面判断返回结果, 或者处理返回的http头中的信息
// 数据接收
- (void)connection:(NSURLConnection *)aConn didReceiveData:(NSData *)data{    [_data appendData:data];}
// 网络错误时触发
- (void)connection:(NSURLConnection *)aConn didFailWithError:(NSError *)error;

// 全部数据接收完毕时触发
- (void)connectionDidFinishLoading:(NSURLConnection *)aConn;