objective-c - NSURLConnection 无法识别

Question

当我尝试识别NSURLConnection. 根本imgConnection不承认，xmlConnection而是。

- (void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {

    if (connection == xmlConnection) {
        [dataFinale appendData:data];
        NSLog(@"XML");
    }
    else if (connection == imgConnection){
        [imgData appendData:data];
        NSLog(@"IMG");
    }

}

NSURLRequest *requestImg = [NSURLRequest requestWithURL:urlImg cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:60];

imgConnection = [NSURLConnection connectionWithRequest:requestImg delegate:self];