Android通过SharedPreferences实现自动登录记住用户名和密码功能

package com.dt5000.ischool.activity; import android.annotation.SuppressLint; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.content.SharedPreferences.Editor; import android.os.Bundle; import android.util.Log; import android.view.KeyEvent; import android.view.View; import android.widget.CheckBox; import android.widget.EditText; import com.dt5000.ischool.util.DTUtil; import com.dt5000.ischool.util.MyApplication; /**  * @author： duanyr  * @创建时间： 2012-11-13 下午2:36:47  *  * @类说明：登录界面  */ @SuppressLint("WorldReadableFiles") public class LoginActivity extends DTUtil {   private static final String TAG = "用户登录";   private EditText username;   private EditText password;   private CheckBox autoLogin;   private SharedPreferences sharedPreferences;   private String message;   @Override   public void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     MyApplication.getInstance().addActivity(this);     sharedPreferences = this.getSharedPreferences("userInfo",Context.MODE_WORLD_READABLE);     if (sharedPreferences.getBoolean("AUTO_ISCHECK", false)) {       Intent intent = new Intent();       intent.setClass(LoginActivity.this, MainActivity.class);       startActivity(intent);     } else {       setContentView(R.layout.activity_login);       initView();     }   }   /**    * 初始化视图控件    */   public void initView() {     Log.i(TAG, "初始化视图控件");     username = (EditText) findViewById(R.id.username);     password = (EditText) findViewById(R.id.password);     autoLogin = (CheckBox) findViewById(R.id.autoLogin);     // 默认记住用户名     username.setText(sharedPreferences.getString("userName", ""));   }   /**    * 点击登录按钮时触发的方法    * @param view    */   public void userLogin(View view) {     String usernameString = username.getText().toString();     String passwordString = password.getText().toString();     if (validateUser(usernameString, passwordString)) {       Editor editor = sharedPreferences.edit();       editor.putString("userName", usernameString);       if (autoLogin.isChecked()) {// 自动登录         editor.putString("password", passwordString);         editor.putBoolean("AUTO_ISCHECK", true).commit();       }       editor.commit();       Intent intent = new Intent();       intent.setClass(LoginActivity.this, MainActivity.class);       startActivity(intent);     } else {       alert(this, message);     }   }   //游客登录   public void visitorLogin(View view) {     Intent intent = new Intent();     intent.setClass(LoginActivity.this, MainActivity.class);     startActivity(intent);   }   /**    * 验证用户名密码是否正确    *    * @param username    * @param password    * @return    */   public boolean validateUser(String username, String password) {     Boolean flag = false;     try {       //...此处为调用web服务，验证用户名密码的服务，特此省略       flag = true;     } catch (Exception e) {       // TODO Auto-generated catch block       Log.e(TAG, e.getMessage());       message = "连接服务器失败";     }     return flag;   }   /**    * 点击退出按钮时触发的方法    */   public void logout_listener(View view) {     dialog_Exit(this);   }   /**    * 监听返回按钮，此为登录界面再返回的话给出退出提示    */   public boolean onKeyDown(int keyCode, KeyEvent event) {     if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {       dialog_Exit(this);       return false;     }     return false;   } } 

<?xml version='1.0' encoding='utf-8' standalone='yes' ?> <map> <string name="userName">777</string> <string name="password">111111</string> <boolean name="AUTO_ISCHECK" value="true" /> </map>