存储

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.hanqi.zuoyee.cunchu_denglu">
<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="请输入账号"
    android:id="@+id/et1"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入密码"/>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center">
    <Button
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:text="登录"
        android:onClick="b1"/>
        <Button
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="注册"/>
</LinearLayout>
</LinearLayout>

layout文件

package com.hanqi.zuoyee;

import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;

public class cunchu_denglu extends AppCompatActivity {
    EditText et;
    String zh;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_cunchu_denglu);
        et=(EditText)findViewById(R.id.et1);
        SharedPreferences s=getSharedPreferences("a",MODE_PRIVATE);
        zh=s.getString("zhanghao",null);
        if(zh!=null){
            et.setText(zh);
        }
    }
    public void b1(View v){
        SharedPreferences s=getSharedPreferences("a", MODE_PRIVATE);
        SharedPreferences.Editor editor = s.edit();
       zh=et.getText().toString();
        if(zh.trim().length()==0){
            return;
        }
        editor.putString("zhanghao",zh);
        editor.commit();

    }
}