Android 记住密码和自动登录界面的实现（SharedPreferences 的用法）

原文：http://blog.csdn.net/liuyiming_/article/details/7704923

SharedPreferences介绍：

SharedPreferences是Android平台上一个轻量级的存储类，主要是保存一些常用的配置参数，它是采用xml文件存放数据的，文件存放在”/data/data/shared_prefs”目录下。

SharedPreferences的用法：

由于SharedPreferences是一个接口，而且在这个接口里没有提供写入数据和读取数据的能力。但它是通过其Editor接口中的一些方法来操作SharedPreference的,用法见下面代码：

Context.getSharedPreferences(String name,int mode)来得到一个SharedPreferences实例

name：是指文件名称，不需要加后缀.xml，系统会自动为我们添加上。

mode：是指定读写方式，其值有三种，分别为：

Context.MODE_PRIVATE：指定该SharedPreferences数据只能被本应用程序读、写

Context.MODE_WORLD_READABLE：指定该SharedPreferences数据能被其他应用程序读，但不能写

Context.MODE_WORLD_WRITEABLE：指定该SharedPreferences数据能被其他应用程序读写。

结果截图：

工程目录：

Java代码

LoginActivity.java

“font-family:’Courier New’;”>package com.liu.activity;

import android.app.Activity;
import android.app.backup.SharedPreferencesBackupHelper;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.os.Bundle;
import android.text.Spannable;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.Toast;

public class LoginActivity extends Activity {

    private EditText userName, password;
    private CheckBox rem_pw, auto_login;
    private Button btn_login;
    private ImageButton btnQuit;
    private String userNameValue,passwordValue;
    private SharedPreferences sp;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //去除标题
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.login);

        //获得实例对象
        sp = this.getSharedPreferences(“userInfo”, Context.MODE_WORLD_READABLE);
        userName = (EditText) findViewById(R.id.et_zh);
        password = (EditText) findViewById(R.id.et_mima);
        rem_pw = (CheckBox) findViewById(R.id.cb_mima);
        auto_login = (CheckBox) findViewById(R.id.cb_auto);
        btn_login = (Button) findViewById(R.id.btn_login);
        btnQuit = (ImageButton)findViewById(R.id.img_btn);


        //判断记住密码多选框的状态
      if(sp.getBoolean(“ISCHECK”, false))
        {
          //设置默认是记录密码状态
          rem_pw.setChecked(true);
          userName.setText(sp.getString(”USER_NAME”, “”));
          password.setText(sp.getString(”PASSWORD”, “”));
          //判断自动登陆多选框状态
          if(sp.getBoolean(“AUTO_ISCHECK”, false))
          {
                 //设置默认是自动登录状态
                 auto_login.setChecked(true);
                //跳转界面
                Intent intent = new Intent(LoginActivity.this,LogoActivity.class);
                LoginActivity.this.startActivity(intent);

          }
        }

        // 登录监听事件  现在默认为用户名为：liu 密码：123
        btn_login.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                userNameValue = userName.getText().toString();
                passwordValue = password.getText().toString();

                if(userNameValue.equals(“liu”)&&passwordValue.equals(“123”))
                {
                    Toast.makeText(LoginActivity.this,“登录成功”, Toast.LENGTH_SHORT).show();
                    //登录成功和记住密码框为选中状态才保存用户信息
                    if(rem_pw.isChecked())
                    {
                     //记住用户名、密码、
                      Editor editor = sp.edit();
                      editor.putString(”USER_NAME”, userNameValue);
                      editor.putString(”PASSWORD”,passwordValue);
                      editor.commit();
                    }
                    //跳转界面
                    Intent intent = new Intent(LoginActivity.this,LogoActivity.class);
                    LoginActivity.this.startActivity(intent);
                    //finish();

                }else{

                    Toast.makeText(LoginActivity.this,“用户名或密码错误，请重新登录”, Toast.LENGTH_LONG).show();
                }

            }
        });

        //监听记住密码多选框按钮事件
        rem_pw.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
                if (rem_pw.isChecked()) {

                    System.out.println(”记住密码已选中”);
                    sp.edit().putBoolean(”ISCHECK”, true).commit();

                }else {

                    System.out.println(”记住密码没有选中”);
                    sp.edit().putBoolean(”ISCHECK”, false).commit();

                }

            }
        });

        //监听自动登录多选框事件
        auto_login.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
                if (auto_login.isChecked()) {
                    System.out.println(”自动登录已选中”);
                    sp.edit().putBoolean(”AUTO_ISCHECK”, true).commit();

                } else {
                    System.out.println(”自动登录没有选中”);
                    sp.edit().putBoolean(”AUTO_ISCHECK”, false).commit();
                }
            }
        });

        btnQuit.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                finish();
            }
        });

    }
}

package com.liu.activity;

import android.app.Activity;
import android.app.backup.SharedPreferencesBackupHelper;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.os.Bundle;
import android.text.Spannable;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.Toast;

public class LoginActivity extends Activity {

    private EditText userName, password;
    private CheckBox rem_pw, auto_login;
    private Button btn_login;
    private ImageButton btnQuit;
    private String userNameValue,passwordValue;
    private SharedPreferences sp;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //去除标题
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.login);

        //获得实例对象
        sp = this.getSharedPreferences("userInfo", Context.MODE_WORLD_READABLE);
        userName = (EditText) findViewById(R.id.et_zh);
        password = (EditText) findViewById(R.id.et_mima);
        rem_pw = (CheckBox) findViewById(R.id.cb_mima);
        auto_login = (CheckBox) findViewById(R.id.cb_auto);
        btn_login = (Button) findViewById(R.id.btn_login);
        btnQuit = (ImageButton)findViewById(R.id.img_btn);


        //判断记住密码多选框的状态
      if(sp.getBoolean("ISCHECK", false))
        {
          //设置默认是记录密码状态
          rem_pw.setChecked(true);
          userName.setText(sp.getString("USER_NAME", ""));
          password.setText(sp.getString("PASSWORD", ""));
          //判断自动登陆多选框状态
          if(sp.getBoolean("AUTO_ISCHECK", false))
          {
                 //设置默认是自动登录状态
                 auto_login.setChecked(true);
                //跳转界面
                Intent intent = new Intent(LoginActivity.this,LogoActivity.class);
                LoginActivity.this.startActivity(intent);

          }
        }

        // 登录监听事件  现在默认为用户名为：liu 密码：123
        btn_login.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                userNameValue = userName.getText().toString();
                passwordValue = password.getText().toString();

                if(userNameValue.equals("liu")&&passwordValue.equals("123"))
                {
                    Toast.makeText(LoginActivity.this,"登录成功", Toast.LENGTH_SHORT).show();
                    //登录成功和记住密码框为选中状态才保存用户信息
                    if(rem_pw.isChecked())
                    {
                     //记住用户名、密码、
                      Editor editor = sp.edit();
                      editor.putString("USER_NAME", userNameValue);
                      editor.putString("PASSWORD",passwordValue);
                      editor.commit();
                    }
                    //跳转界面
                    Intent intent = new Intent(LoginActivity.this,LogoActivity.class);
                    LoginActivity.this.startActivity(intent);
                    //finish();

                }else{

                    Toast.makeText(LoginActivity.this,"用户名或密码错误，请重新登录", Toast.LENGTH_LONG).show();
                }

            }
        });

        //监听记住密码多选框按钮事件
        rem_pw.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
                if (rem_pw.isChecked()) {

                    System.out.println("记住密码已选中");
                    sp.edit().putBoolean("ISCHECK", true).commit();

                }else {

                    System.out.println("记住密码没有选中");
                    sp.edit().putBoolean("ISCHECK", false).commit();

                }

            }
        });

        //监听自动登录多选框事件
        auto_login.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
                if (auto_login.isChecked()) {
                    System.out.println("自动登录已选中");
                    sp.edit().putBoolean("AUTO_ISCHECK", true).commit();

                } else {
                    System.out.println("自动登录没有选中");
                    sp.edit().putBoolean("AUTO_ISCHECK", false).commit();
                }
            }
        });

        btnQuit.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                finish();
            }
        });

    }
}

LogoActivity.java

“font-family:’Courier New’;”>package com.liu.activity;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.opengl.ETC1;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.Animation.AnimationListener;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.ProgressBar;

public class LogoActivity extends Activity {
    private ProgressBar progressBar;
    private Button backButton;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 去除标题
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.logo);

        progressBar = (ProgressBar) findViewById(R.id.pgBar);
        backButton = (Button) findViewById(R.id.btn_back);

        Intent intent = new Intent(this, WelcomeAvtivity.class);
        LogoActivity.this.startActivity(intent);

        backButton.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                finish();

            }
        });

    }

}

package com.liu.activity;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.opengl.ETC1;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.Animation.AnimationListener;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.ProgressBar;

public class LogoActivity extends Activity {
    private ProgressBar progressBar;
    private Button backButton;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 去除标题
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.logo);

        progressBar = (ProgressBar) findViewById(R.id.pgBar);
        backButton = (Button) findViewById(R.id.btn_back);

        Intent intent = new Intent(this, WelcomeAvtivity.class);
        LogoActivity.this.startActivity(intent);

        backButton.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                finish();

            }
        });

    }

}

WelcomeActivity.java

“font-family:’Courier New’;”>“BACKGROUND-COLOR: rgb(240,240,240); WHITE-SPACE: pre”>package com.liu.activity;
import android.app.Activity;
import android.os.Bundle;

public class WelcomeAvtivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.welcome);
    }

}

package com.liu.activity;
import android.app.Activity;
import android.os.Bundle;

public class WelcomeAvtivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.welcome);
    }

}

布局文件：

login.xml文件

<span style=“font-family:’Courier New’;”>xml version=“1.0” encoding=“utf-8”?>
<LinearLayout xmlns:android=“http://schemas.android.com/apk/res/android”
    android:layout_width=“fill_parent”
    android:layout_height=“fill_parent”
    android:background=“@drawable/logo_bg”
    android:orientation=“vertical” >

    <RelativeLayout
        android:layout_width=“fill_parent”
        android:layout_height=“wrap_content” >
        <ImageButton
            android:id=“@+id/img_btn”
            android:layout_width=“wrap_content”
            android:layout_height=“wrap_content”
            android:layout_alignParentRight=“true”
            android:background=“@drawable/quit”/>

        <TextView
            android:id=“@+id/tv_zh”
            android:layout_width=“wrap_content”
            android:layout_height=“35dip”
            android:layout_marginLeft=“12dip”
            android:layout_marginTop=“10dip”
            android:gravity=“bottom”
            android:text=“帐号:”
            android:textColor=“#000000”
            android:textSize=“18sp” />

        <EditText
            android:id=“@+id/et_zh”
            android:layout_width=“fill_parent”
            android:layout_height=“40dip”
            android:layout_below=“@id/tv_zh”
            android:layout_marginLeft=“12dip”
            android:layout_marginRight=“10dip” />

        <TextView
            android:id=“@+id/tv_mima”
            android:layout_width=“wrap_content”
            android:layout_height=“35dip”
            android:layout_below=“@id/et_zh”
            android:layout_marginLeft=“12dip”
            android:layout_marginTop=“10dip”
            android:gravity=“bottom”
            android:text=“密码:”
            android:textColor=“#000000”
            android:textSize=“18sp” />

        <EditText
            android:id=“@+id/et_mima”
            android:layout_width=“fill_parent”
            android:layout_height=“40dip”
            android:layout_below=“@id/tv_mima”
            android:layout_marginLeft=“12dip”
            android:layout_marginRight=“10dip”
            android:maxLines=“200”
            android:password=“true”
            android:scrollHorizontally=“true” />

        <CheckBox
            android:id=“@+id/cb_mima”
            android:layout_width=“wrap_content”
            android:layout_height=“wrap_content”
            android:layout_below=“@id/et_mima”
            android:layout_marginLeft=“12dip”
            android:text=“记住密码”
            android:textColor=“#000000” />

        <CheckBox
            android:id=“@+id/cb_auto”
            android:layout_width=“wrap_content”
            android:layout_height=“wrap_content”
            android:layout_below=“@id/cb_mima”
            android:layout_marginLeft=“12dip”
            android:text=“自动登录”
            android:textColor=“#000000” />
        <Button
            android:id=“@+id/btn_login”
            android:layout_width=“80dip”
            android:layout_height=“40dip”
            android:layout_below=“@id/et_mima”
            android:layout_alignParentRight=“true”
            android:layout_alignTop=“@id/cb_auto”
            android:layout_marginRight=“10dip”
            android:gravity=“center”
            android:text=“登录”
            android:textColor=“#000000”
            android:textSize=“18sp”/>


    RelativeLayout>



LinearLayout>span>

logo.xml文件

<span style=“font-family:’Courier New’;”>xml version=“1.0” encoding=“utf-8”?>
<LinearLayout xmlns:android=“http://schemas.android.com/apk/res/android”
    android:layout_width=“fill_parent”
    android:layout_height=“fill_parent”
    android:background=“@drawable/logo_bg”
    android:orientation=“vertical” >

    <RelativeLayout
        android:layout_width=“fill_parent”
        android:layout_height=“wrap_content”
        android:layout_weight=“3”>

        <ProgressBar
            android:id=“@+id/pgBar”
            android:layout_width=“wrap_content”
            android:layout_height=“wrap_content”
            android:layout_centerInParent=“true” />

        <TextView
            android:id=“@+id/tv1”
            android:layout_width=“wrap_content”
            android:layout_height=“wrap_content”
            android:layout_below=“@id/pgBar”
            android:layout_centerHorizontal=“true”
            android:text=“正在登录…”
            android:textColor=“#000000”
            android:textSize=“18sp” />
    RelativeLayout>

    <LinearLayout
        android:layout_width=“fill_parent”
        android:layout_height=“wrap_content”
        android:layout_weight=“1”
        android:gravity=“center”
        android:orientation=“vertical” >

        <Button
            android:id=“@+id/btn_back”
            android:layout_width=“70dip”
            android:layout_height=“35dip”
            android:text=“取消”
            android:textColor=“#000000”
            android:textSize=“12sp” />
    LinearLayout>


LinearLayout>span>

welcome.xml

<span style=“font-family:’Courier New’;”>xml version=“1.0” encoding=“utf-8”?>
<LinearLayout xmlns:android=“http://schemas.android.com/apk/res/android”
    android:layout_width=“fill_parent”
    android:layout_height=“fill_parent”
    android:layout_gravity=“center”
    android:background=“@drawable/login_bg”
    android:orientation=“vertical” >

    <TextView
        android:layout_width=“fill_parent”
        android:layout_height=“wrap_content”
        android:gravity=“center”
        android:text=“登陆成功，进入用户界面”
        android:textColor=“#000000”
        android:textSize=“20sp” />

LinearLayout>span>

工程下载连接： 点击打开链接