如何使用 NSDictionary 从 JSON 数据访问所有索引集

Question

我正在尝试获取我从服务器获取的用户名和密码。我已经存储在 jsondata 中，即 NSMutableArray。但是我通过 -objectAtIndex: 只获得了一个数据。我想在字典中调用我的所有数据。我知道我必须使用 NSIndexSet 但我不知道正确的使用方法。我正在使用 for 循环。我无法访问我的密钥值以匹配用户凭据。有人可以提出任何建议吗？这是我的代码：

    NSDictionary *dict = [jsondata objectAtIndex:0];

    if ([username.text isEqualToString:[dict valueForKey:@"username"]]&&[password.text isEqualToString:[dict valueForKey:@"password"]]) {
        username.text=nil;
        password.text=nil;

        [self performSegueWithIdentifier:@"login" sender:nil];

    }
    else {
        UIAlertView *error=[[UIAlertView alloc]initWithTitle:@"Oooops" message:@"Login Credentials did`t Match" delegate:self cancelButtonTitle:@"ok" otherButtonTitles:nil];
        [error show];

    }

Answer 1

您需要调用一个循环来访问jsondata 上的所有数据。调用如下：

for (int i=0; i<[jsondata count]; i++)
{
 NSDictionary *dict = [jsondata objectAtIndex:i];
    if ([username.text isEqualToString:[NSString stringWithFormat: @"%@",[dict valueForKey:@"username"]]]&&[password.text isEqualToString:[NSString stringWithFormat: @"%@",[dict valueForKey:@"password"]]]) {
        username.text=nil;
        password.text=nil;

        [self performSegueWithIdentifier:@"login" sender:nil];

}

    else {
    UIAlertView *error=[[UIAlertView alloc]initWithTitle:@"Alert Title" message:@"Your alert messege" delegate:self cancelButtonTitle:@"ok" otherButtonTitles:nil];
    [error show];

}
}

Answer 2

NSString *tusername = nil;
NSString *tpassword = nil;
BOOL isLogin = NO;

//jsondata contains many dictionary, so iterate the loop and find the dictionary that
//contains username and password
for(id temp in jsondata)
{
    //check whether the object is Dictionary or not
    if([temp isKindOfClass:[NSDictionary class]])
        {

            NSDictionary *dict = temp;
            if([[dict allKeys] containsObject:@"username"])
            {
                tusername = [dict valueForKey:@"username"];
            }
            else if([[dict allKeys] containsObject:@"password"])
            {
                tpassword = [dict valueForKey:@"password"];
            }
           //Check the condition here
           if(tusername != nil && tpassword != nil)
           {
          if ([username.text isEqualToString:tusername] && [password.text isEqualToString:tpassword])
           {
                 isLogin = YES;
                 username.text=nil;
                 password.text=nil;
        [self performSegueWithIdentifier:@"login" sender:nil];
        break;
           }
          }

     }
}

  if(!isLogin)
  {
        UIAlertView *error=[[UIAlertView alloc]initWithTitle:@"Oooops" message:@"Login Credentials did`t Match" delegate:self cancelButtonTitle:@"ok" otherButtonTitles:nil];
        [error show];

    }

如何使用 NSDictionary 从 JSON 数据访问所有索引集

how to access all index set from JSON data using NSDictionary

ios

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