Android 实现记住用户名和密码的功能

绪论

首先记住密码功能要用到SharedPreferences类，这个类可以实现简单的存储，主要用于保存窗口状态

结果图如下：

代码

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 checkbox = 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);
checkbox = (CheckBox) findViewById(R.id.checkBoxLogin);
   login = (Button) findViewById(R.id.new_user);
   if (sp.getBoolean("auto", false))
  {
     uname.setText(sp.getString("uname", null));
     upswd.setText(sp.getString("upswd", null)); 
     checkbox.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 autoLogin = checkbox.isChecked();
if (autoLogin)
{
Editor editor = sp.edit();
editor.putString("uname", name);
editor.putString("upswd", pswd);
editor.putBoolean("auto", true);
editor.commit();
}
else
{  
Editor editor = sp.edit();
editor.putString("uname", null);
editor.putString("upswd", null);
editor.putBoolean("auto", 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);

}
}

layout_main.xml

content.xml