Android 实现记住用户名和密码的效能

简介

Android 实现记住用户名和密码的功能是通过SharedPreference 存储来实现的。创建一个复选按钮，通过按钮的否选取来进行事件处理。若按钮选中存储账号和密码的信息。若按钮没有选中，则清空账号和密码的信息。

结果演示：

源代码下载地址：

https://github.com/GXS1225/Android————-.git

分析

（1）判断是否输入了账号和密码

    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;            }

（2）在layout_main.xml定义一个 CheckBox，进行事件处理

//通过boolean CheckBoxLogin = checkbox.isChecked();            //按钮被选中，下次进入时会显示账号和密码                                      if (CheckBoxLogin)            {                    Editor editor = sp.edit();                    editor.putString("uname", name);                    editor.putString("upswd", pswd);                    editor.putBoolean("auto", true);                    editor.commit();            }            //按钮被选中，清空账号和密码，下次进入时会显示账号和密码                          else                        {                  Editor editor = sp.edit();                editor.putString("uname", null);                editor.putString("upswd", null);                editor.putBoolean("auto", false);                editor.commit();                }

（3） SharedPreference 的存储实现

//先定义SharedPreferences sp = null; sp = this.getSharedPreferences("userinfo", Context.MODE_PRIVATE);//对uname 和 upswd 的操作 if (sp.getBoolean("checkboxBoolean", false))            {                uname.setText(sp.getString("uname", null));                upswd.setText(sp.getString("upswd", null));                 checkboxButton.setChecked(true);            }

（4）跳转到Content.java界面

//Intent跳转Intent intent = new Intent(Welcome.this,Content.class);startActivity(intent);finish();

步骤

先写一个登陆的界面： 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>

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

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>