Android 实现记住用户名和密码的功能

最近学了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

<?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>

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>