iPhone에서 서버 답장을 아는 방법?

Question

- (IBAction) uploadImage { 
    /* 
    turning the image into a NSData object 
    getting the image back out of the UIImageView 
    setting the quality to 100 
    */ 
     NSData *imageData = UIImageJPEGRepresentation(image.image, 100); 
     // setting up the URL to post to 
    NSString *urlString = @"http://uploadhere.com/photos/iphone.php"; 

    // setting up the request object now 
    NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease]; 
    [request setURL:[NSURL URLWithString:urlString]]; 
    [request setHTTPMethod:@"POST"]; 

    /* 
    add some header info now 
    we always need a boundary when we post a file 
    also we need to set the content type 

    You might want to generate a random boundary.. this is just the same 
    as my output from wireshark on a valid html post 
    */ 
    NSString *boundary = [NSString stringWithString:@"---------------------------14737809831466499882746641449"]; 
    NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary]; 
    [request addValue:contentType forHTTPHeaderField: @"Content-Type"]; 

    /* 
    now lets create the body of the post 
    */ 
    NSMutableData *body = [NSMutableData data]; 
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];  
    [body appendData:[[NSString stringWithString:@"Content-Disposition: form-data; name=\"q\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; 
    [body appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; 
    [body appendData:[NSData dataWithData:imageData]]; 
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]]; 
    NSLog(@"here1"); 
    // setting the body of the post to the reqeust 
    [request setHTTPBody:body]; 
    NSLog(@"here2"); 
    // now lets make the connection to the web 
    NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil]; 
    returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding]; 
    NSLog(@"here3"); 
    //NSLog(returnString); 
    //picText = rowZero.pickerLabel.text; 
    NSLog(@"here4"); 
    rowZero.path  = returnString; 
    //NSLog(rowZero.path); 


} 

웹 섹션과의 연결에서이 현상이 발생합니다.

이 코드를 사용하여 서버에 이미지를 업로드하고 있습니다. 그러나,이 NSLog(@"%@", returnData) 내게 값을주고 있지만 NSLog(@"%@", returnString) null 값을 반환합니다. 내 이미지가 서버에 업로드되고 있는지 여부를 어떻게 알 수 있습니까?

Answer 1

요청이 성공했는지 확인하려면 returningResponse 및 error을 사용해야합니다.

... 
NSURLResponse *response = nil; 
NSError *error = nil; 

NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error]; 

if (error != nil) { 
    // Handle error. Response code can be retrieved from NSURLResponse 
}