android开发用户和密码登陆

绪论

首先记住密码功能要用到SharedPreferences类，这个类不仅可以实现简单的存储，还主要用于保存窗口状态等等。

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跳转语句

   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>