CFNetwork错误：由于URL格式错误，连接失败

Question

在运行iphone app时，我多次遇到以下错误

The connection failed due to a malformed URL

在CFNetwork Error Codes Reference，我收到了CFNetwork触发此错误的信息

• 何时以及为何触发此错误？
• 如何摆脱这个错误？

Answer 1

NSURLConnection有一个方法canHandleRequest，它会返回一个布尔值，无论url是否有效，例如

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;
}