ios - 如何在 Parse 中使用重复的用户名检查注册

Question

我正在使用以下代码通过 Swift 注册 Parse 帐户。

var user = PFUser()
user.username = self.userNameText.text
user.password = self.paswordText.text
user["mobileNumber"] = self.mobileNo as! String     //
user["authCode"] = self.authCode as! String
user["deviceId"] = deviceId
self.user.signUpInBackgroundWithBlock({
            (success:Bool, error:NSError?) -> Void in
            if (error == nil) {
                let installation:PFInstallation = PFInstallation.currentInstallation()
                installation["user"] = PFUser.currentUser()
                installation.saveInBackgroundWithBlock({
                    (success:Bool, error:NSError?) -> Void in
                    if (error == nil) {
                        println("Installion Success")
                    } else {
                        println("Installation Error")
                    }
                })
                println("Singup Success")
            } else { 
                println(" error = \(error)")
            }
})

在此如果输入的用户名已经保存在 Parse 中，我想给出错误，但现在它使用 2 个相同的用户名成功注册。

我怎样才能避免这种情况？

Answer 1

If you want to Check that User is Already signup via Parse.com then You have to make a query in the User table If User already exists then don't allow him to again signup

PFQuery *query = [PFUser query];
[query whereKey:@"username" equalTo:textField.text];

[query getFirstObjectInBackgroundWithBlock:^(PFObject *object, NSError *error) {
if (object != nil) {
    NSLog(@"User exist");
}
else
{
    NSLog(@"User don`t exist");
}
}]; 

希望对你有帮助