當EditText為空Android Studio時禁用按鈕？

Question

我是新人，沒有經驗。 我看到了一些禁用登錄按鈕的代碼。 我試圖將它添加到代碼中。 但我沒有成功。 當字段為空時，按下登錄按鈕時應用程序停止。

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        binding = ActivityLoginBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());

        auth = FirebaseAuth.getInstance();

        dialog = new ProgressDialog(this);
        dialog.setMessage("Logging in...");

        if(auth.getCurrentUser() != null) {
            startActivity(new Intent(LoginActivity.this, MainActivity.class));
            finish();
        }

        binding.submitBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String email, pass;

                email = binding.emailBox.getText().toString();
                pass = binding.passwordBox.getText().toString();

                dialog.show();

                auth.signInWithEmailAndPassword(email, pass).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        dialog.dismiss();

                        if(task.isSuccessful()) {
                            startActivity(new Intent(LoginActivity.this, MainActivity.class));
                            finish();
                        } else {
                            Toast.makeText(LoginActivity.this, task.getException().getLocalizedMessage(), Toast.LENGTH_SHORT).show();
                        }
                    }
                });
            }
        });

        binding.createNewBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(LoginActivity.this, SignupActivity.class));
            }
        });
    }
}

Answer 1

您應該檢查email pattern 和password ，而不僅僅是檢查空字段，還應該檢查 length > 6 否則Firebase Auth會拋出異常。 為您的submitBtn偵聽器使用以下代碼：

        binding.submitBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                String email = binding.emailBox.getText().toString();
                String pass = binding.passwordBox.getText().toString();

                if (email.isEmpty()) {
                    binding.emailBox.setError("Email is required");
                    binding.emailBox.requestFocus();
                    return;
                }

                if (!Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
                    binding.emailBox.setError("Email is not valid");
                    binding.emailBox.requestFocus();
                    return;
                }

                if (pass.isEmpty()) {
                    binding.passwordBox.setError("Password is required");
                    binding.passwordBox.requestFocus();
                    return;
                }

                if (pass.length() < 6) {
                    binding.passwordBox.setError("Password is weak");
                    binding.passwordBox.requestFocus();
                    return;
                }
                
                dialog.show();

                auth.signInWithEmailAndPassword(email, pass).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        dialog.dismiss();

                        if(task.isSuccessful()) {
                            startActivity(new Intent(LoginActivity.this, MainActivity.class));
                            finish();
                        } else {
                            Toast.makeText(LoginActivity.this, task.getException().getLocalizedMessage(), Toast.LENGTH_SHORT).show();
                        }
                    }
                });
            }
        });