java - 如何使用 Android Studio 在 firebase 中检查 "user email already exists"

Question

我正在尝试更改我的代码。但是，它失败了。我的输出仍然相同。也就是说，如果用户放置了一个已经存在或不存在的电子邮件。验证“此电子邮件已注册。”还是出来了。为什么？有人能知道我的编码有什么问题吗？

这是我的方法:-

public boolean isCheckEmail(final String email)
{
    mAuth.fetchProvidersForEmail(email).addOnCompleteListener(new OnCompleteListener<ProviderQueryResult>()
    {
        @Override
        public void onComplete(@NonNull Task<ProviderQueryResult> task)
        {
            boolean check = !task.getResult().getProviders().isEmpty();

            if(check)
            {
                Toast.makeText(Signup.this, "This email has been registered.", Toast.LENGTH_SHORT).show();
            }

            else
            {
                Toast.makeText(Signup.this, "This email has been registered.", Toast.LENGTH_SHORT).show();
            }
        }
    });
    return true;
}

在这一半的编码过程中，我试图回调方法 isCheckEmail:-

 private void RegisterAccount(String firstname, String lastname, String email, String password, String confirmpass)
{
    if (TextUtils.isEmpty(email))
    {
        Toast.makeText(Signup.this, "Enter your email address.", Toast.LENGTH_SHORT).show();
    }

    else if (!isValidEmail(email)) {
        Toast.makeText(Signup.this,"Please enter your valid email address.",Toast.LENGTH_SHORT).show();
    }

    else if (!isCheckEmail(email))
    {
        Toast.makeText(Signup.this, "This email has been registered.", Toast.LENGTH_SHORT).show();
    }

Answer 1

此方法用于检查电子邮件是否存在

 void checkEmailExistsOrNot(){
    firebaseauth.fetchSignInMethodsForEmail(email.getText().toString()).addOnCompleteListener(new OnCompleteListener<SignInMethodQueryResult>() {
        @Override
        public void onComplete(@NonNull Task<SignInMethodQueryResult> task) {
            Log.d(TAG,""+task.getResult().getSignInMethods().size());
            if (task.getResult().getSignInMethods().size() == 0){
                // email not existed
            }else {
                // email existed
            }

        }
    }).addOnFailureListener(new OnFailureListener() {
        @Override
        public void onFailure(@NonNull Exception e) {
            e.printStackTrace();
        }
    });
}