Android实现一个记住密码的登陆界面

Android实现一个记住密码的登陆界面

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1、设计思路：

主要采用SharedPreferences来保存用户数据，本Demo没有经过加密，所有一旦Android系统被ROOT的话，其他用户就可以查看用户的私有目录，密码文件就很不安全。所以真正应用在软件上面的，一定要经过加密才保存，可以选择MD5加密。

 

SharedPreferences介绍可以参看这篇博文：http://blog.csdn.net/conowen/article/details/7312612

TextWatcher的介绍可以参看这篇博文：http://blog.csdn.net/conowen/article/details/7420673

 

2、功能介绍

默认勾选“记住密码”复选框，点击“登陆”按钮，一旦成功登陆，就保存用户名和密码到SharedPreferences文件中。

 

用户名输入时，通过TextWatcher不断去读取用户数据，自动提示相应的“用户名”，选择了用户名之后，就会读取SharedPreferences的文件，然后自动完成密码的输入。

 

3、效果图：

 

 

4、代码：详细都在注释里面了

001/*author: conowen

002 * date: 2012.4.2

003 *

004 */

005package com.conowen.remeberPwd;

006 

007import android.app.Activity;

008import android.content.SharedPreferences;

009import android.os.Bundle;

010import android.text.Editable;

011import android.text.InputType;

012import android.text.TextWatcher;

013import android.view.View;

014import android.view.View.OnClickListener;

015import android.widget.ArrayAdapter;

016import android.widget.AutoCompleteTextView;

017import android.widget.Button;

018import android.widget.CheckBox;

019import android.widget.EditText;

020import android.widget.Toast;

021 

022public class RemeberPwdActivity extends Activity {

023 

024    AutoCompleteTextView cardNumAuto;

025    EditText passwordET;

026    Button logBT;

027 

028    CheckBox savePasswordCB;

029    SharedPreferences sp;

030    String cardNumStr;

031    String passwordStr;

032 

033    /** Called when the activity is first created. */

034    @Override

035    public void onCreate(Bundle savedInstanceState) {

036        super.onCreate(savedInstanceState);

037        setContentView(R.layout.main);

038        cardNumAuto = (AutoCompleteTextView) findViewById(R.id.cardNumAuto);

039        passwordET = (EditText) findViewById(R.id.passwordET);

040        logBT = (Button) findViewById(R.id.logBT);

041 

042        sp = this.getSharedPreferences("passwordFile", MODE_PRIVATE);

043        savePasswordCB = (CheckBox) findViewById(R.id.savePasswordCB);

044        savePasswordCB.setChecked(true);// 默认为记住密码

045        cardNumAuto.setThreshold(1);// 输入1个字母就开始自动提示

046        passwordET.setInputType(InputType.TYPE_CLASS_TEXT

047                | InputType.TYPE_TEXT_VARIATION_PASSWORD);

048        // 隐藏密码为InputType.TYPE_TEXT_VARIATION_PASSWORD，也就是0x81

049        // 显示密码为InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD，也就是0x91

050 

051        cardNumAuto.addTextChangedListener(new TextWatcher() {

052 

053            @Override

054            public void onTextChanged(CharSequence s, int start, int before,

055                    int count) {

056                // TODO Auto-generated method stub

057                String[] allUserName = new String[sp.getAll().size()];// sp.getAll().size()返回的是有多少个键值对

058                allUserName = sp.getAll().keySet().toArray(new String[0]);

059                // sp.getAll()返回一张hash map

060                // keySet()得到的是a set of the keys.

061                // hash map是由key-value组成的

062 

063                ArrayAdapter<String> adapter = new ArrayAdapter<String>(

064                        RemeberPwdActivity.this,

065                        android.R.layout.simple_dropdown_item_1line,

066                        allUserName);

067 

068                cardNumAuto.setAdapter(adapter);// 设置数据适配器

069 

070            }

071 

072            @Override

073            public void beforeTextChanged(CharSequence s, int start, int count,

074                    int after) {

075                // TODO Auto-generated method stub

076 

077            }

078 

079            @Override

080            public void afterTextChanged(Editable s) {

081                // TODO Auto-generated method stub

082                passwordET.setText(sp.getString(cardNumAuto.getText()

083                        .toString(), ""));// 自动输入密码

084 

085            }

086        });

087 

088        // 登陆

089        logBT.setOnClickListener(new OnClickListener() {

090 

091            @Override

092            public void onClick(View v) {

093                // TODO Auto-generated method stub

094 

095                cardNumStr = cardNumAuto.getText().toString();

096                passwordStr = passwordET.getText().toString();

097 

098                if (!((cardNumStr.equals("test")) && (passwordStr

099                        .equals("test")))) {

100                    Toast.makeText(RemeberPwdActivity.this, "密码错误，请重新输入",

101                            Toast.LENGTH_SHORT).show();

102                } else {

103                    if (savePasswordCB.isChecked()) {// 登陆成功才保存密码

104                        sp.edit().putString(cardNumStr, passwordStr).commit();

105                    }

106                    Toast.makeText(RemeberPwdActivity.this, "登陆成功，正在获取用户数据……",

107                            Toast.LENGTH_SHORT).show();

108                    // 跳转到另一个Activity

109                    // do something

110 

111                }

112 

113            }

114        });

115 

116    }

117 

118}

布局文件：main.xml

001<?xml version="1.0" encoding="utf-8"?>

002<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

003    android:layout_width="fill_parent"

004    android:layout_height="fill_parent"

005    android:orientation="vertical" >

006 

007    <TextView

008        android:layout_width="wrap_content"

009        android:layout_height="wrap_content"

010        android:layout_gravity="center_horizontal"

011        android:text="简单登陆DEMO"

012        android:textSize="25px" />

013 

014    <LinearLayout

015        xmlns:android="http://schemas.android.com/apk/res/android"

016        android:layout_width="fill_parent"

017        android:layout_height="fill_parent"

018        android:gravity="center"

019        android:orientation="vertical" >

020 

021        <LinearLayout

022            android:layout_width="250dip"

023            android:layout_height="wrap_content"

024            android:layout_marginLeft="10dp"

025            android:layout_marginRight="10dp"

026            android:layout_marginTop="15dp"

027            android:orientation="vertical" >

028 

029            <LinearLayout

030                android:layout_width="fill_parent"

031                android:layout_height="wrap_content"

032                android:orientation="horizontal" >

033 

034                <LinearLayout

035                    android:layout_width="fill_parent"

036                    android:layout_height="80px"

037                    android:orientation="vertical" >

038 

039                    <LinearLayout

040                        android:layout_width="fill_parent"

041                        android:layout_height="40px"

042                        android:orientation="horizontal" >

043 

044                        <TextView

045                            android:id="@+id/tv_account"

046                            android:layout_width="wrap_content"

047                            android:layout_height="wrap_content"

048                            android:layout_marginRight="10dp"

049                            android:text="用  户  名:"

050                            android:textSize="15px" />

051 

052                        <AutoCompleteTextView

053                            android:id="@+id/cardNumAuto"

054                            android:layout_width="fill_parent"

055                            android:layout_height="40px" >

056                        </AutoCompleteTextView>

057                    </LinearLayout>

058 

059                    <LinearLayout

060                        android:layout_width="fill_parent"

061                        android:layout_height="40px"

062                        android:orientation="horizontal" >

063 

064                        <TextView

065                            android:layout_width="wrap_content"

066                            android:layout_height="wrap_content"

067                            android:layout_marginRight="10dp"

068                            android:text="用户密码:"

069                            android:textSize="15px" />

070 

071                        <EditText

072                            android:id="@+id/passwordET"

073                            android:layout_width="fill_parent"

074                            android:layout_height="40px" >

075                        </EditText>

076                    </LinearLayout>

077                </LinearLayout>

078            </LinearLayout>

079 

080            <LinearLayout

081                android:layout_width="wrap_content"

082                android:layout_height="wrap_content"

083                android:orientation="horizontal" >

084 

085                <CheckBox

086                    android:id="@+id/savePasswordCB"

087                    android:layout_width="wrap_content"

088                    android:layout_height="wrap_content"

089                    android:layout_marginLeft="20dp"

090                    android:text="记住密码" >

091                </CheckBox>

092 

093                <Button

094                    android:id="@+id/logBT"

095                    android:layout_width="100px"

096                    android:layout_height="wrap_content"

097                    android:layout_marginLeft="40dp"

098                    android:layout_marginRight="10dp"

099                    android:text="登录" >

100                </Button>

101            </LinearLayout>

102        </LinearLayout>

103    </LinearLayout>

104 

105</LinearLayout>

SharedPreferences文件，在/data/data/包名/shared_prefs文件夹下面

1<?xml version='1.0' encoding='utf-8' standalone='yes' ?>

2<map>

3<string name="test">test</string>

4<string name="test2">test</string>

5<string name="test1">test</string>

6</map>