登入頁面及程式碼：

activity_signin.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width
 
="match_parent"
    android:layout_height="match_parent"
    tools:context=".SigninActivity">

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:orientation="vertical"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf
 
="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.0"
        android:padding="10dp">

        <TextView
            android:id="@+id/TextView"
            android:layout_width="match_parent
 
"
            android:layout_height="wrap_content"
            android:text="登入介面"
            android:textSize="22sp"
            android:textStyle="bold"
            android:gravity="center"/>

        <EditText
            android:id="@+id/et_signin_id"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:ems="10"
            android:hint="姓名"
            android:maxLines="1"
            android:inputType="textPersonName"
            android:text="" />

        <EditText
            android:id="@+id/et_signin_password"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:ems="10"
            android:hint="密碼"
            android:maxLines="1"
            android:inputType="textPassword" />

        <Button
            android:id="@+id/btn_signin_submit"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@android:color/holo_blue_bright"
            android:textStyle="bold"
            android:onClick="btn_start_siginin_onclick"
            android:layout_marginTop="30dp"
            android:text="登入" />

    </LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

SigninActivity.java

package com.example.tem;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

public class SigninActivity extends AppCompatActivity {

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

    public void btn_start_siginin_onclick(View view) {
        EditText etId=findViewById(R.id.et_signin_id);
        EditText etPassword=findViewById(R.id.et_signin_password);
        Intent intent=new Intent();
        intent.putExtra("id",etId.getText().toString());
        intent.putExtra("password",etPassword.getText().toString());
        setResult(0,intent);
        finish();
    }
}