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

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<package name>/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。

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

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
[java] view plain copy print?<span style=“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();                }          });        }    }  </span>  
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
[java] view plain copy print?<span style=“font-family:’Courier New’;”><span style=“BACKGROUND-COLOR: rgb(240,240,240); WHITE-SPACE: pre”>package com.liu.activity;</span>  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);      }    }</span>  
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
[html] view plain copy print?<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>  
<?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>
logo.xml文件
[html] view plain copy print?<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>  
<?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>welcome.xml
[html] view plain copy print?<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>  
<?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>
工程下载连接：点击打开链接