AFNetworking網址中有中文崩潰的問題

    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    manager.responseSerializer = [AFHTTPResponseSerializer serializer];
    manager.requestSerializer.timeoutInterval = 15;
    manager.responseSerializer.acceptableContentTypes = [NSSet setWithObjects:@"application/json",@"text/json",@"text/plain",@"text/html", nil];
    NSString *url =  [NSString stringWithFormat:@"http://中文.com"];
    url = [ur stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];