JAVA:

package com.example.myapplication;
 
import androidx.appcompat.app.AppCompatActivity;
 
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
 
public class SharedActivity extends AppCompatActivity {
    private EditText shared1;
    private Button shared2,shared3;
    private TextView shared4;
    private SharedPreferences mSharedPreferences;
    private SharedPreferences.Editor mEditor;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_shared);
        shared1=findViewById(R.id.shared1);
        shared2=findViewById(R.id.shared2);
        shared3=findViewById(R.id.shared3);
        shared4=findViewById(R.id.shared4);
 
        mSharedPreferences=getSharedPreferences("data",MODE_PRIVATE);
        mEditor=mSharedPreferences.edit();
 
        shared2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               mEditor.putString("name",shared1.getText().toString());
               mEditor.commit();
                Toast.makeText(SharedActivity.this,"儲存完畢",Toast.LENGTH_SHORT).show();
            }
        });
        shared3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               shared4.setText(mSharedPreferences.getString("name",""));
            }
        });
    }

XML：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dp"
   >
    <EditText
        android:layout_marginTop="50dp"
        android:id="@+id/shared1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="請輸入要儲存的名字："
        android:textSize="20sp"/>
    <Button
        android:layout_marginTop="20dp"
        android:id="@+id/shared2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="20dp"
        android:text="儲存"/>
    <Button
        android:id="@+id/shared3"
        android:layout_marginTop="20dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="20dp"
        android:text="檢視"/>
    <TextView
        android:layout_marginTop="40dp"
        android:id="@+id/shared4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="20dp"/>
 
</LinearLayout>