Android 使用DevicePolicyManager實現螢幕上鎖功能

在Android 2.2的時候推出了一個新的類別Device Administration
其主要功能可以使用管理者權限讓螢幕上鎖等等得功能

今天要實做的上鎖功能，必須實做的元件有Activity、DeviceAdminReceiver以及一個DeviceAdminInfo會使用的Xml檔案。

重點在於實做了DeviceAdminReceiver這個廣播，註冊時要將DeviceAdminInfo所使用的Xml一起註冊在DeviceAdminReceiver廣播內，必須幫廣播加入下方的權限

android:permission=”android.permission.BIND_DEVICE_ADMIN”

Activity程式碼如下：

package com.example.demo;

import android.app.Activity;
import android.app.admin.DevicePolicyManager;
import android.content.ComponentName;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {
    protected final int UnRegistration = 0;
    protected final int LockScreen = 1;
    private DevicePolicyManager devicePolicyManager;
    private ComponentName componentName;
    private Button btn_Lock;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
    }

    @Override
    protected void onPause() {
        UnReg_Lock(UnRegistration);
        super.onPause();
    }

    @Override
    protected void onResume() {
        super.onResume();

    }

    private void init() {
        devicePolicyManager = (DevicePolicyManager) getSystemService(DEVICE_POLICY_SERVICE);
        componentName = new ComponentName(this, AdminReceiver.class);
        btn_Lock = (Button) findViewById(R.id.button1);
        btn_Lock.setOnClickListener(lock);
        Registration();

    }

    private void Registration() {
        Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
        intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, componentName);
        intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION,
                "程式的描述");
        startActivityForResult(intent, 0);
    }

    private void UnReg_Lock(int sltNum) {
        if (devicePolicyManager.isAdminActive(componentName)) {
            switch (sltNum) {
            case UnRegistration:
                devicePolicyManager.removeActiveAdmin(componentName);
                break;
            case LockScreen:
                devicePolicyManager.lockNow();
                break;
            }
        }
    }

    private Button.OnClickListener lock = new Button.OnClickListener() {
        public void onClick(View arg0) {
            UnReg_Lock(LockScreen);
        }
    };
}

DeviceAdminReceiver程式碼如下：

package com.example.demo;

import android.app.admin.DeviceAdminReceiver;
import android.app.admin.DevicePolicyManager;
import android.content.Context;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;

public class AdminReceiver extends DeviceAdminReceiver {
    private final String Tag = "Tag：";

    public DevicePolicyManager getManger(Context context) {
        Log.e(Tag, "調用getManger()");
        return super.getManager(context);
    }

    @Override
    public IBinder peekService(Context myContext, Intent service) {
        Log.e(Tag, "調用peekService()");
        return super.peekService(myContext, service);
    }

    @Override
    public CharSequence onDisableRequested(Context context, Intent intent) {
        Log.e(Tag, "調用onDisableRequested()");
        return super.onDisableRequested(context, intent);
    }

    @Override
    public void onDisabled(Context context, Intent intent) {
        Log.e(Tag, "管理權限取消");
        super.onDisabled(context, intent);
    }

    @Override
    public void onEnabled(Context context, Intent intent) {
        Log.e(Tag, "管理權限開啟");
        super.onEnabled(context, intent);
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        Log.e(Tag, "調用onReceive()");
        super.onReceive(context, intent);
    }

}

deviceinfo.xml：

<?xml version="1.0" encoding="utf-8"?>
<device-admin xmlns:android="http://schemas.android.com/apk/res/android" >

    <uses-policies>

        <!-- 今天只使用螢幕鎖定的功能，所以沒有加入其他資訊 -->
        <force-lock />
    </uses-policies>

</device-admin>

AndroidManifest.xml：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.demo"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <receiver
            android:name="AdminReceiver"
            android:description="@string/description"
            android:label="@string/label"
            android:permission="android.permission.BIND_DEVICE_ADMIN" >
            <meta-data
                android:name="android.app.device_admin"
                android:resource="@xml/deviceinfo" />
        </receiver>
    </application>

</manifest>