解析Json来处理和引导用户到视图控制器.Objective - C

Question

我有一个登录屏幕，我将用户名和密码发送到登录页面。

webservice给我2个响应，如果登录用户的详细信息是正确的，我从请求中得到一个返回的响应。

{"价值":1}

，如果用户的详细信息是错误的，我从请求返回。

{"价值":0}

我已经能够解析JSON结果给我一个日志输出

value: 1或value:0

我正在努力处理解析json，例如

 //parse out the json data
NSDictionary* json = [NSJSONSerialization JSONObjectWithData:urlData //1
                                                     options:kNilOptions
                                                       error:&error];
NSArray* defineJsonData = [json objectForKey:@"value"]; //2
NSLog(@"value: %@", defineJsonData); //3
if ([[json objectForKey:@"value"] isEqualToNumber:[NSNumber numberWithInt:1]])
{
    HUD.customView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"37x-Checkmark.png"]];
    HUD.mode = MBProgressHUDModeCustomView;
    [HUD hide:YES afterDelay:0];
    [self performSegueWithIdentifier: @"introScreenView" sender:self];
}
else {
    HUD.customView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"37x-Checkmark.png"]];
    HUD.mode = MBProgressHUDModeCustomView;
    [HUD hide:YES afterDelay:0];
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Wrong Credentials" message:@"Please try to login again" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
    [alert show];
}

下面是我剩下的代码。

- (void)myTask {
if ([userNameTextField.text isEqualToString:@""] || [passwordTextField.text isEqualToString:@""]) {
    HUD.customView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"37x-Checkmark.png"]];
    HUD.mode = MBProgressHUDModeCustomView;
    [HUD hide:YES afterDelay:0];
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Feilds Missing" message:@"Please Fill all the field" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
    [alert show];
    return;
}
NSString *data = [NSString stringWithFormat:@"UserName=%@&Password=%@",userNameTextField.text, passwordTextField.text];
NSData *postData = [data dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];
// preaparing URL request to send data.
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init] ;
NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:request delegate:self];
NSString *url = [NSString stringWithFormat:@"http://www.ddproam.co.za/Central/Account/LogOnIOS?"];
[request setURL:[NSURL URLWithString:url]];
[request setHTTPMethod:@"POST"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setHTTPBody:postData];
[request setTimeoutInterval:7.0];
NSURLResponse *response;
NSError *error;
NSData *urlData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
NSString *str=[[NSString alloc]initWithData:urlData encoding:NSUTF8StringEncoding];
NSLog(@"Login response:%@",str);
NSHTTPCookie *cookie;
NSLog(@"name: '%@'n",   [cookie name]);
for (NSHTTPCookie *cookie in [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookies])
{
    NSLog(@"name: '%@'n",   [cookie name]);
    NSLog(@"value: '%@'n",  [cookie value]);
    NSLog(@"domain: '%@'n", [cookie domain]);
    NSLog(@"path: '%@'n",   [cookie path]);
}

//parse out the json data
NSDictionary* json = [NSJSONSerialization JSONObjectWithData:urlData //1
                                                     options:kNilOptions
                                                       error:&error];
NSArray* defineJsonData = [json objectForKey:@"value"]; //2
NSLog(@"value: %@", defineJsonData); //3
if ([defineJsonData isEqual:0])
{
    HUD.customView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"37x-Checkmark.png"]];
    HUD.mode = MBProgressHUDModeCustomView;
    [HUD hide:YES afterDelay:0];
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Wrong Credentials" message:@"Please try to login again" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
    [alert show];
}
else {
    HUD.customView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"37x-Checkmark.png"]];
    HUD.mode = MBProgressHUDModeCustomView;
    [HUD hide:YES afterDelay:0];
    [self performSegueWithIdentifier: @"introScreenView" sender:self];
}

if (theConnection) {

}
}

Answer 1

如果来自服务器的响应确实只是{"value":1}，那么使用NSJSONSerialization正确解析JSON到字典

但是在value key下，有NSNumber的实例，没有NSArray的实例。

检索value并检查它的代码应该是这样的:

NSNumber *defineJsonData = [json objectForKey:@"value"];
NSLog(@"value: %@", defineJsonData);
if ([defineJsonData integerValue] == 0) {
    NSLog(@"Wrong credentials");
}
else {
    NSLog(@"Welcome :-)");
}