Question

我通过单击UIButton执行JSON POST请求，在提交后，可以执行segue执行。因此，提交值后，我再也无法执行POST请求。它显示状态代码200并且响应正常。但是，数据不会反映在后端。这是我的代码：

(IBAction)transitsurveydone:(id)sender {
    if([tempArray count]!=0){
       /* alert= [[UIAlertView alloc] initWithTitle:@"Survey Submission"
                                          message:@"Please Enter your location"
                                         delegate:self
                                cancelButtonTitle:@"Modify"
                                otherButtonTitles:@"Submit",nil];
        alert.alertViewStyle = UIAlertViewStylePlainTextInput;
        alert.tag=2;
        [alert show];*/

        NSLog(@"Caption array is %@ %@",captionArray,tempArray);

        NSURL *URL = [NSURL URLWithString:[NSString stringWithFormat:@"myURL"]];

        NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];
        [request setHTTPMethod:@"POST"];
        [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];

        NSMutableDictionary *postDict = [[NSMutableDictionary alloc]init];


        NSMutableDictionary *d=[[NSMutableDictionary alloc] initWithObjectsAndKeys:@10,@"\"Bus\"", nil];
            NSMutableArray *m=[[NSMutableArray alloc] init];

        NSString *str1,*str2,*str3,*str4;
               // Checking the format






        if(tempArray.count==1){
            for (int x=0; x<1; x++) {
                str1=[NSString stringWithFormat:@"\"%@\"",[captionArray objectAtIndex:x]];
                [d setObject:[tempArray objectAtIndex:x]  forKey:str1];


            }


        [request setHTTPBody:[[NSString stringWithFormat: @"{\n    \"instance\" : %@,\n    \"response_method\": \"web\",\n    \"routes\": [\n                {%@:%@}\n        ]\n}",randomString,str1,[d objectForKey:str1] ]dataUsingEncoding:NSUTF8StringEncoding]];
        }
          NSLog(@"%@:%@",str1,[d objectForKey:str1]);        
        NSURLSession *session = [NSURLSession sharedSession];
        NSURLSessionDataTask *task = [session dataTaskWithRequest:request
                                                completionHandler:
                                      ^(NSData *data, NSURLResponse *response, NSError *error) {

                                          if (error) {
                                              // Handle error...
                                              return;
                                          }

                                          if ([response isKindOfClass:[NSHTTPURLResponse class]]) {
                                              NSLog(@"Response HTTP Status code: %ld\n", (long)[(NSHTTPURLResponse *)response statusCode]);
                                              NSLog(@"Response HTTP Headers:\n%@\n", [(NSHTTPURLResponse *)response allHeaderFields]);
                                          }

                                          NSString* body = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
                                          NSLog(@"Response Body:\n%@\n", body);
                                      }];
        [task resume];


        NSHTTPURLResponse *response = nil;
        NSError *error = nil;


        NSData *respData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
        NSLog(@"~~~~~ Status code: %d", [response statusCode]);

        if([response statusCode]==200){
            UIAlertView  *alert = [[UIAlertView alloc] initWithTitle:nil message:@"Transit Survey submitted" delegate:self cancelButtonTitle:nil otherButtonTitles:nil];
            alert.transform = CGAffineTransformMakeTranslation( 10, 740);
            [alert show];
            [self performSelector:@selector(dismissAlert:) withObject:alert afterDelay:1.0f];
            submitteddonthide=NO;
        }
        else{
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:@"Transit Survey Submission Failed" delegate:self cancelButtonTitle:nil otherButtonTitles:nil];
        alert.transform = CGAffineTransformMakeTranslation( 10, 740);
        [alert show];
        [self performSelector:@selector(dismissAlert:) withObject:alert afterDelay:1.0f];
        }


        if([prefs integerForKey:@"humandone"]==1){
            [self performSegueWithIdentifier:@"transittohuman" sender:nil];
        }
        else{
            [self performSegueWithIdentifier:@"gobackfromtransit" sender:nil];
        }


    }

`

以上代码在IBAction中

Answer 1

您的代码看起来很好，没有任何问题。如果这个问题一直发生，请添加＆＃34; Advanced Rest Client＆＃34;附加到Chrome浏览器并测试您的服务器URL传递相应的输入值。如果此流程无法更新后端的值，则后端应该会出现问题。

Answer 2

有几点想法：

您正在使用状态代码来确定服务器是否正确插入数据。您实际上应该让您的Web服务构建一个肯定的响应（在JSON中，会很棒），说明数据是否已成功插入。您不应仅仅依赖Web服务器的请求响应代码。
我会观察Charles之类的请求，并确保它看起来不错。
您手动构建JSON请求，这非常脆弱。我建议使用Charles来观察请求，并将其复制并粘贴到http://jsonlint.com中，并确保它没问题。
更好的是，使用更健壮，更易于使用的NSJSONSerialization。
此外，您还要两次发送此请求。丢失第二个请求（不管怎样你不应该做同步请求）并将所有确认逻辑放在会话的完成处理程序块中。

Answer 3

是。经过一段时间的努力，清理饼干给了我很多帮助： -

这是一大堆代码，非常简单

 NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage];
 NSArray *cookies = [cookieStorage cookiesForURL:[NSURL URLWithString:urlString]];
    for (NSHTTPCookie *cookie in cookies) {
        NSLog(@"Deleting cookie for domain: %@", [cookie domain]);
        [cookieStorage deleteCookie:cookie];
    }

感谢reddys先生和Rob先生的建议

NSMutableRequest第二次不工作（启用ARC）

3 个答案: