| 实验的实施阶段 |
实验步骤及实验结果 |
activity_main.xml <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="60dp"
android:layout_height="60dp"
android:background="@drawable/jay"
android:layout_centerHorizontal="true"
android:layout_marginTop="100dp"
android:id="@+id/iv" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/LL1"
android:layout_below="@+id/iv"
android:layout_marginTop="30dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="账号："
android:layout_marginLeft="10dp"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/et1"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/LL2"
android:layout_below="@+id/LL1">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="密码："
android:layout_marginLeft="10dp"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:password="true"
android:id="@+id/et2"/>
</LinearLayout>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="登录"
android:layout_below="@+id/LL2"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp"
android:id="@+id/btn"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/btn"
android:id="@+id/tv_account"
android:layout_marginLeft="10dp"
android:layout_marginTop="20dp"
android:textColor="#00f"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/tv_account"
android:id="@+id/tv_password"
android:layout_marginLeft="10dp"
android:textColor="#f00"/>
</RelativeLayout> MainActivity.java package com.example.shiyan3;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import java.util.Map;
public class MainActivity extends AppCompatActivity {
private EditText et_account;
private EditText et_password;
private Button login;
private TextView tv_a;
private TextView tv_p;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_account=findViewById(R.id.et1);
et_password=findViewById(R.id.et2);
login=findViewById(R.id.btn);
tv_a=findViewById(R.id.tv_account);
tv_p=findViewById(R.id.tv_password);
login.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String account=et_account.getText().toString();
String password=et_password.getText().toString();
if(account.isEmpty()){
Toast.makeText(MainActivity.this,"请输入账号",Toast.LENGTH_SHORT).show();
return;
}
if(password.isEmpty()){
Toast.makeText(MainActivity.this,"请输入密码",Toast.LENGTH_SHORT).show();
return;
}
boolean isSaveSuccess=FileSaveLogin.saveUserInfo(MainActivity.this,account,password);
if (isSaveSuccess){
Toast.makeText(MainActivity.this,"保存成功",Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(MainActivity.this,"保存失败",Toast.LENGTH_SHORT).show();
}
Map<String,String>userInfo=FileSaveLogin.getUserInfo(MainActivity.this);
if(userInfo!=null){
tv_a.setText("输入的账号为："+userInfo.get("account"));
tv_p.setText("输入的密码为："+userInfo.get("password"));
}
else{
Toast.makeText(MainActivity.this,"保存信息为空",Toast.LENGTH_SHORT).show();
}
}
});
}
} FileSaveLogin.java package com.example.shiyan3;
import android.content.Context;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;
public class FileSaveLogin {
public static Boolean saveUserInfo(Context context,String account,String password){
FileOutputStream fos=null;
try{
fos=context.openFileOutput("data.txt",Context.MODE_PRIVATE);
fos.write((account+":"+password).getBytes());
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}finally {
try{
if(fos!=null) {
fos.close();
}
}
catch (IOException e) {
e.printStackTrace();
}
}
}
public static Map<String,String> getUserInfo(Context context){
FileInputStream fis=null;
String content="";
try{
fis=context.openFileInput("data.txt");
byte[] buffer=new byte[fis.available()];
fis.read(buffer);
content=new String(buffer);
Map<String,String> myMap=new HashMap<>();
String[]infos=content.split(":");
myMap.put("account",infos[0]);
myMap.put("password",infos[1]);
return myMap;
}catch (Exception e){
e.printStackTrace();
return null;
}finally {
try {
if(fis!=null){
fis.close();
}
}catch (IOException e)
{
e.printStackTrace();
}
}
}
} |