iphone網絡post鏈接的兩種處理方式(同步和異步)

第一種： 直接返回方式。

-(void)UpadaPost:(NSString *)strcontext URL:(NSString *)urlstr{

NSLog(urlstr);
NSLog(strcontext);
assert(strcontext != NULL);
assert(urlstr != NULL);

NSData *postData = [strcontext dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];  

NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];  

NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];  
[request setURL:[NSURL URLWithString:urlstr]];  
[request setHTTPMethod:@"POST"];  
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];  
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];  
[request setHTTPBody:postData];  

NSURLResponse *respone;
NSError *error;
NSData *myReturn =[NSURLConnection sendSynchronousRequest:request returningResponse:&respone
error:error];
NSLog(@"%@", [[NSString alloc] initWithData:myReturn encoding:NSUTF8StringEncoding]);
}

第二種，採用事件代理方式

-(void)UpadaPost:(NSString *)strcontext URL:(NSString *)urlstr{

NSLog(urlstr);
NSLog(strcontext);
assert(strcontext != NULL);
assert(urlstr != NULL);

NSData *postData = [strcontext dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];  

NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];  

NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];  
[request setURL:[NSURL URLWithString:urlstr]];  
[request setHTTPMethod:@"POST"];  
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];  
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];  
[request setHTTPBody:postData];  

NSURLConnection *conn=[[NSURLConnection alloc] initWithRequest:request delegate:self];  
if (conn)    
{  
NSLog(@"Connection success");
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
[conn retain];

}    
else    
{  
// inform the user that the download could not be made  
}  

}



// 收到響應時, 會觸發
- (void)connection:(NSURLConnection *)connection  didReceiveResponse:(NSURLResponse *)response  {
// 注意這裏將NSURLResponse對象轉換成NSHTTPURLResponse對象才能去
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse*)response;
if ([response respondsToSelector:@selector(allHeaderFields)]) {
NSDictionary *dictionary = [httpResponse allHeaderFields];
NSLog([dictionary description]);
NSLog(@"%d",[response statusCode]);

}
}


// Forward errors to the delegate.
//連接錯誤   
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
//[self performSelectorOnMainThread:@selector(httpConnectEnd) withObject:nil waitUntilDone:NO];
NSLog(@"%@",[error localizedDescription]);

}

// Called when a chunk of data has been downloaded.
//接收數據 每收到一次數據, 會調用一次
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
// Process the downloaded chunk of data.

NSLog(@"%d", [data length]);
//NSLog(@"%@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);

//[self performSelectorOnMainThread:@selector(updateProgress) withObject:nil waitUntilDone:NO];


}
//接收結束
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {

NSLog(@"%@",connection);
//NSLog(@"%lld", received_);

//[self performSelectorOnMainThread:@selector(httpConnectEnd) withObject:nil waitUntilDone:NO];
// Set the condition which ends the run loop.
}