在代码中使用FirebaseUI的最新版本替换AuthUI，然后使用startActivityForResult()方法。

以下是实现解决方法的示例代码：

// 导入FirebaseUI import com.firebase.ui.auth.AuthUI; import com.firebase.ui.auth.FirebaseAuthUIActivityResultContract; import com.firebase.ui.auth.data.model.FirebaseAuthUIAuthenticationResult; import com.google.firebase.auth.FirebaseAuth; import com.google.firebase.auth.FirebaseUser;

public class MainActivity extends AppCompatActivity {

private static final int RC_SIGN_IN = 123;

// 创建FirebaseUI登录契约
private final FirebaseAuthUIActivityResultContract signInLauncher = new FirebaseAuthUIActivityResultContract(
        AuthUI.getInstance()
                .createSignInIntentBuilder()
                .setAvailableProviders(
                        Arrays.asList(
                                new AuthUI.IdpConfig.EmailBuilder().build(),
                                new AuthUI.IdpConfig.GoogleBuilder().build()
                        ))
                .build()) {
    @NonNull
    @Override
    protected Intent createIntent(@NonNull Context context) {
        return AuthUI.getInstance()
                .createSignInIntentBuilder()
                .setAvailableProviders(
                        Arrays.asList(
                                new AuthUI.IdpConfig.EmailBuilder().build(),
                                new AuthUI.IdpConfig.GoogleBuilder().build()
                        ))
                .build();
    }

    @Override
    protected void parseResult(
            int resultCode,
            @Nullable Intent intent,
            @NonNull FirebaseAuthUIAuthenticationResult outcome) {
        FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
        if (user != null) {
            // 处理登录成功的情况
            Toast.makeText(
                    this, "欢迎 " + user.getDisplayName() + "!", Toast.LENGTH_LONG)
                    .show();
        } else {
            // 处理登录失败的情况
            Toast.makeText(this, "登录失败...", Toast.LENGTH_LONG).show();
        }
    }
};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // 启动FirebaseUI登录流程
    ActivityResultLauncher launcher = registerForActivityResult(signInLauncher,
            outcome -> {
                // 在此处处理登录结果
            });
    launcher.launch(null);
}

}

在上面的示例代码中，我们使用了FirebaseUI的最新版本，创建了一个FirebaseUI登录契约，并使用registerForActivityResult()方法启动了登录流程。当登录完成后，我们可以在parseResult()方法中处理登录成功或失败的情况。