1.

package com.example.innerfilesave;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.b1);
        findViewById(R.id.b2);
        EditText editText1=findViewById(R.id.et_in);
        EditText editText2=findViewById(R.id.et_out);
    }
    public void click1(View view){
        EditText editText1=findViewById(R.id.et_in);
        EditText editText2=findViewById(R.id.et_out);
        String filename="data.txt";
        String context=editText1.getText().toString();
        FileOutputStream fos=null;
        try {
            fos=openFileOutput(filename,MODE_PRIVATE);
            fos.write(context.getBytes());
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            if (fos!=null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        Toast.makeText(this,"保存成功",Toast.LENGTH_SHORT).show();

    }
    public void click2(View view){
        EditText editText2=findViewById(R.id.et_out);
        String context="";
        FileInputStream fis=null;
        try {
            fis=openFileInput("data.txt");
            byte[]buffer=new byte[fis.available()];
            fis.read(buffer);
            context=new String(buffer);
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            if (fis!=null) {
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        editText2.setText(context);
    }
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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=".MainActivity"
    android:orientation="vertical">

   <EditText
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:hint="输入你想要写入的内容"
       android:layout_margin="10dp"
       android:id="@+id/et_in"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="写入"
        android:layout_margin="10dp"
        android:id="@+id/b1"
        android:onClick="click1"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="显示读取的内容"
        android:layout_margin="10dp"
        android:id="@+id/et_out"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="读取"
        android:layout_margin="10dp"
        android:id="@+id/b2"
        android:onClick="click2"/>



</LinearLayout>

 

 

2.

package com.example.myapplication;
import java.util.Map;

import android.os.Bundle;
import android.app.Activity;
import android.content.DialogInterface.OnClickListener;
import android.content.SharedPreferences.Editor;
import android.text.TextUtils;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.EditText;
import android.widget.Toast;

import androidx.annotation.CheckResult;

public class MainActivity extends Activity implements android.view.View.OnClickListener , CompoundButton.OnCheckedChangeListener {

    private EditText et_account;
    private EditText et_password;
    private Button btn_login;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        Map<String, String> userInfo=qq.getUserInfo(this);
        if(userInfo!=null){
            et_account.setText(userInfo.get("account"));
            et_password.setText(userInfo.get("password"));
        }
    }
    private void initView() {
        // TODO Auto-generated method stub
        et_account=(EditText)findViewById(R.id.user);
        et_password=(EditText)findViewById(R.id.password);
        btn_login=(Button)findViewById(R.id.b1);
        btn_login.setOnClickListener(this);
        CheckBox cb1=findViewById(R.id.cb1);
        cb1.setOnCheckedChangeListener(this);
        CheckBox cb2=findViewById(R.id.cb2);
        cb2.setOnCheckedChangeListener(this);
    }
    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch(v.getId()){
            case R.id.b1:
                String account=et_account.getText().toString().trim();
                String password=et_password.getText().toString();
                if(TextUtils.isEmpty(account)){
                    Toast.makeText(this, "请输入账号", Toast.LENGTH_SHORT).show();
                    return;
                }
                if(TextUtils.isEmpty(password)){
                    Toast.makeText(this, "请输入密码", Toast.LENGTH_SHORT).show();
                    return;
                }
                Toast.makeText(this, "登录成功", Toast.LENGTH_SHORT).show();

        }

    }

    @Override
    public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
        switch (compoundButton.getId()){
            case R.id.cb1 :
                String account=et_account.getText().toString().trim();
                String password=et_password.getText().toString();
                boolean isSaveSuccess=qq.saveUserInfo(this, account, password);
                if(isSaveSuccess&&b){
                    Toast.makeText(this, "保存成功", Toast.LENGTH_SHORT).show();
                }else{
                    Toast.makeText(this, "保存失败", Toast.LENGTH_SHORT).show();
                    et_account.setText(null);
                    et_password.setText(null);
                }

                break;
            case R.id.cb2: account=et_account.getText().toString().trim();
                password=et_password.getText().toString();
                if(TextUtils.isEmpty(account)){
                    Toast.makeText(this, "请输入账号", Toast.LENGTH_SHORT).show();
                    return;
                }
                if(TextUtils.isEmpty(password)){
                    Toast.makeText(this, "请输入密码", Toast.LENGTH_SHORT).show();
                    return;
                }
                if(b)
                    Toast.makeText(this, "登录成功", Toast.LENGTH_SHORT).show();
                else{
                    Toast.makeText(this, "请登录", Toast.LENGTH_SHORT).show();
                }

        }
    }
}
<?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=".MainActivity">

    <TextView
        android:id="@+id/zhanghu"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="账号"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.041"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.081" />

    <EditText
        android:id="@+id/user"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="52dp"
        android:layout_marginLeft="52dp"
        android:layout_toRightOf="@id/zhanghu"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.064" />

    <TextView
        android:id="@+id/mima"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/zhanghu"
        android:text="密码"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.041"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.186" />

    <EditText
        android:id="@+id/password"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/user"
        android:layout_marginStart="52dp"
        android:layout_marginLeft="52dp"
        android:layout_toRightOf="@id/mima"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.193" />

    <Button
        android:id="@+id/b1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/cb2"
        android:layout_alignRight="@+id/password"
        android:layout_alignBottom="@+id/cb2"
        android:text="登录"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.894"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.276" />

    <CheckBox
        android:id="@+id/cb1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/mima"
        android:layout_alignLeft="@+id/mima"

        android:text="记住密码"
        android:textSize="10sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.27" />

    <CheckBox
        android:id="@+id/cb2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/cb1"
        android:layout_alignBottom="@+id/cb1"
        android:layout_toRightOf="@+id/cb1"
        android:text="自动登录"
        android:textSize="10sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.427"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.27" />

 

posted on 2021-11-01 16:34  郝梦瑶  阅读(43)  评论(0编辑  收藏  举报