CFNetwork的错误：连接失败，因为一个错误的URL

Question

在运行iPhone应用程序，有好几次我得到了以下错误

The connection failed due to a malformed URL 

在CFNetwork Error Codes Reference，我得到的信息，这个错误被CFNetwork的

触发
• 何时以及为什么会触发此错误？
• 如何摆脱这个错误？

Answer 1

NSURLConnection有一个canHandleRequest方法，无论url是否有效，它都会返回一个boolean值。

NSString *strUrl = [NSString stringWithFormat:@"http://test.com/stopBoard/%i",busStopCode]; 
NSURL *url = [NSURL URLWithString:strUrl]; 
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url 
               cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData 
              timeoutInterval:20.0]; 
// a cache policy of NO must be used otherwise the previous query is used if the phone is not online 

BOOL canGo = [NSURLConnection canHandleRequest:request]; 
if(canGo){ 
    connection = [[NSURLConnection alloc] initWithRequest:request 
               delegate:self 
             startImmediately:YES]; 


} else { 
    self.errorMessage = @"\n\nurl check failed\n\n"; 
    return NO; 
}