Android实现记住用户名和密码功能

Android 实现记住用户名和密码的功能是通过SharedPreference 存储来实现的。创建一个复选按钮，通过按钮的否选取来进行事件处理。若按钮选中存储账号和密码的信息。若按钮没有选中，则清空账号和密码的信息。

结果演示：

源代码下载地址：

https://github.com/GXS1225/Android————-.git

分析

（1）判断是否输入了账号和密码

 if(name.trim().equals("")){
    Toast.makeText(this, "请您输入用户名！", Toast.LENGTH_SHORT).show();
    return;
   }
   if(pswd.trim().equals("")){
    Toast.makeText(this, "请您输入密码！", Toast.LENGTH_SHORT).show();
    return;
   }

（2）在layout_main.xml定义一个 CheckBox，进行事件处理

//通过
boolean CheckBoxLogin = checkbox.isChecked();
   //按钮被选中，下次进入时会显示账号和密码
   if (CheckBoxLogin)
   {
     Editor editor = sp.edit();
     editor.putString("uname", name);
     editor.putString("upswd", pswd);
     editor.putBoolean("auto", true);
     editor.commit();
   }
   //按钮被选中，清空账号和密码，下次进入时会显示账号和密码
   else
   {
    Editor editor = sp.edit();
    editor.putString("uname", null);
    editor.putString("upswd", null);
    editor.putBoolean("auto", false);
    editor.commit();
    }

（3） SharedPreference 的存储实现

//先定义
SharedPreferences sp = null; 

sp = this.getSharedPreferences("userinfo", Context.MODE_PRIVATE);
//对uname 和 upswd 的操作
 if (sp.getBoolean("checkboxBoolean", false))
   {
    uname.setText(sp.getString("uname", null));
    upswd.setText(sp.getString("upswd", null));
    checkboxButton.setChecked(true);

   }

（4）跳转到Content.java界面

//Intent跳转
Intent intent = new Intent(Welcome.this,Content.class);
startActivity(intent);
finish();

步骤：

先写一个登陆的界面： layout_main.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:background="#ADD8E6">

 <RelativeLayout
  android:id="@+id/login_div"
  android:layout_width="fill_parent"
  android:layout_height="221dp"
  android:layout_margin="15dip"
  android:background="@drawable/btn_bg"
  android:padding="15dip" >

  <TextView
   android:id="@+id/login_user_input"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_alignParentTop="true"
   android:layout_margin="5dp"
   android:text="@string/user"
   android:textSize="16dp"
   android:typeface="sans" />

  <EditText
   android:id="@+id/user_input"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:layout_below="@id/login_user_input"
   android:background="@android:drawable/editbox_background"
   android:inputType="text"
   android:singleLine="true" />

  <TextView
   android:id="@+id/login_pass_input"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_below="@id/user_input"
   android:layout_margin="5dp"
   android:text="@string/pass"
   android:textSize="16dp"
   android:typeface="sans" />

  <EditText
   android:id="@+id/pass_input"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:layout_below="@id/login_pass_input"
   android:background="@android:drawable/editbox_background"
   android:inputType="textPassword"
   android:singleLine="true" />

  <CheckBox
   android:id="@+id/checkBoxLogin"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_alignLeft="@+id/pass_input"
   android:layout_alignParentBottom="true"
   android:text="@string/no_user" />

  <Button
   android:id="@+id/new_user"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_alignParentBottom="true"
   android:layout_alignRight="@+id/pass_input"
   android:layout_marginRight="28dp"
   android:onClick="To_Title"
   android:text="@string/new_user" />

 </RelativeLayout>

  <LinearLayout
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:orientation="vertical" >

   <TextView
    android:layout_width="402dp"
    android:layout_height="51dp"
    android:layout_marginLeft="50dp"
    android:background="@drawable/gxs_ziti" />

   <Button
    android:layout_width="120dp"
    android:layout_height="120dp"
    android:onClick="To_fruist"
    android:background="@drawable/gxs2"
    android:layout_marginLeft="80dp"
    />

  </LinearLayout>

</LinearLayout>

Welcome.java

package com.gxs.login;
import com.example.login.R;
import com.gxs.listview.*;
import android.os.Bundle;
import android.preference.Preference;
import android.app.Activity;
import android.app.SearchManager.OnCancelListener;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;
public class Welcome extends Activity implements OnClickListener{
 private EditText uname = null;
 private EditText upswd = null;
 private CheckBox checkboxButton = null;
 private Button login = null;
 SharedPreferences sp = null;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.layout_main);
  sp = this.getSharedPreferences("userinfo", Context.MODE_PRIVATE);
  init();

 }

 public void init()
 {
  uname = (EditText) findViewById(R.id.user_input);
  upswd = (EditText) findViewById(R.id.pass_input);
  checkboxButton = (CheckBox) findViewById(R.id.checkBoxLogin);
  login = (Button) findViewById(R.id.new_user);
  if (sp.getBoolean("checkboxBoolean", false))
   {
    uname.setText(sp.getString("uname", null));
    upswd.setText(sp.getString("upswd", null));
    checkboxButton.setChecked(true);

   }
  login.setOnClickListener(this);
 }

 @Override
 public void onClick(View v) {
  if (v == login){
   String name = uname.getText().toString();
   String pswd = upswd.getText().toString();
   if(name.trim().equals("")){
    Toast.makeText(this,
    "请您输入用户名！", Toast.LENGTH_SHORT).show();
    return;
   }
   if(pswd.trim().equals("")){
    Toast.makeText(this,
    "请您输入密码！", Toast.LENGTH_SHORT).show();
    return;
   }
   boolean CheckBoxLogin = checkboxButton.isChecked();
   if (CheckBoxLogin)
   {
     Editor editor = sp.edit();
     editor.putString("uname", name);
     editor.putString("upswd", pswd);
     editor.putBoolean("checkboxBoolean", true);
     editor.commit();
   }
   else
   {
    Editor editor = sp.edit();
    editor.putString("uname", null);
    editor.putString("upswd", null);
    editor.putBoolean("checkboxBoolean", false);
    editor.commit();
    }
   //Intent跳转
   Intent intent=new Intent(Welcome.this,Content.class);
   startActivity(intent);
   finish();
  }
 }

}

Content.java

package com.gxs.listview;
import java.util.List;
import com.example.login.R;
import com.gxs.*;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class Content extends Activity{
 private ListView listview_fruits;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  // TODO Auto-generated method stub
  super.onCreate(savedInstanceState);
  setContentView(R.layout.content);

 }
}

content.xml

<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:paddingBottom="@dimen/activity_vertical_margin"
 android:paddingLeft="@dimen/activity_horizontal_margin"
 android:paddingRight="@dimen/activity_horizontal_margin"
 android:paddingTop="@dimen/activity_vertical_margin"
 tools:context=".Welcome"
 >

 <TextView
  android:id="@+id/textView1"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="内容"
  android:textAppearance="?android:attr/textAppearanceLarge" />

</LinearLayout>

更多内容请参考专题：Android密码使用教程

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