正在从其他PFUser更改PFUser中的字段，解析iOS

Question

我正在尝试更改另一个PFUser字段的值，从另一个未验证的PFUser解析，但是我似乎不能这样做。我正在尝试从一个用户增加另一个用户的“小时数”。下面是我尝试这样做的方法：

PFUser *currentUser = [PFUser currentUser];
PFACL *ACL = [PFACL ACLWithUser:[PFUser currentUser]];
[ACL setPublicReadAccess:YES];

PFUser *selectedUser = [self.formValues objectForKey:@"user"];
NSLog(@"User ID: %@", selectedUser.objectId);

PFObject *volunteerSheet = [PFObject objectWithClassName:@"VolunteerSheet"];
volunteerSheet[@"userID"] = selectedUser.objectId;
volunteerSheet[@"fromID"] = currentUser.objectId;
volunteerSheet[@"volunteerTitle"] = [self.formValues objectForKey:@"title"];
volunteerSheet[@"location"] = [self.formValues objectForKey:@"location"];
volunteerSheet[@"volunteerHours"] = [self.formValues objectForKey:@"hours"];
volunteerSheet[@"volunteerDescription"] = [self.formValues objectForKey:@"description"];
volunteerSheet.ACL = ACL;
[volunteerSheet saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
    if (succeeded) {
        // The object has been saved.
        PFQuery *query = [PFQuery queryWithClassName:@"_User"];

        // Retrieve the object by id
        [query getObjectInBackgroundWithId:selectedUser.objectId
                                     block:^(PFObject *user, NSError *error) {
                                         [user incrementKey:@"volunteerHours" byAmount:(NSNumber*)[self.formValues objectForKey:@"hours"]];
                                         [user saveInBackgroundWithBlock:^(BOOL succeeded, NSError * _Nullable error) {
                                             if (succeeded) {
                                                 NSLog(@"Succeeded");
                                             }else{
                                                 NSLog(error.description);
                                             }
                                         }];
                                     }];

        NSLog(@"Saved");
        [self dismissViewControllerAnimated:YES completion:^{
            UIAlertView * alert =[[UIAlertView alloc ] initWithTitle:@"Success!"
                                                             message:@"Hours Sent succesfully."
                                                            delegate:self
                                                   cancelButtonTitle:nil
                                                   otherButtonTitles: nil];
            [alert addButtonWithTitle:@"Okay"];
            [alert show];
        }];
    } else {
        // There was a problem, check error.description
        NSLog(@"Error: %@",error.description);
    }
}];

Answer 1

用户会自动设置安全措施，禁止修改其他用户(clps或alcs)。也许可以考虑转而使用云代码，并使用主密钥调用？

Answer 2

用户将ACL设置为仅允许自己更改其值。要解决此问题，您必须在每次创建用户时更改ACL，以允许任何用户拥有对其的写权限(非常危险且根本不安全)，或者需要调用云函数Parse.Cloud.useMasterKey()，该函数将覆盖所有权限，并使您能够进行更改。显然，在进行这些更改之前，您仍然应该做一些安全检查，以确保这些更改是允许的/适当的更改。