锁屏DevicePolicyManager申请系统管理权限

效果图：

　　

 

Caused by:  java.lang.SecurityException: No active admin owned by uid 10038 for policy #3
该错误需要把应用程序升级为拥有系统管理员权限，写一个广播接收者，给该广播接收者去申请系统管理员的权限，让操作系统给广播接收者授权。（其实就去激活系统的一个授权的组件）让用户自己激活。

锁屏步骤:

1.创建 MyAdmin 的广播接受者 继承 DeviceAdminReceiver

package com.example.lockscreen;import android.app.admin.DeviceAdminReceiver;public class MyAdmin extends DeviceAdminReceiver {}

2.清单文件中的配置：

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.lockscreen"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="8" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.example.lockscreen.MainActivity"            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=".MyAdmin" >            <meta-data android:name="android.app.device_admin"                android:resource="@xml/my_admin"/>            <intent-filter >                <action android:name="android.app.action.DEVICE_ADMIN_ENABLED"/>            </intent-filter>        </receiver>    </application></manifest>

3.在res文件建立xml/my_admin.xml文件：

<?xml version="1.0" encoding="utf-8" ?><device-admin xmlns:android="http://schemas.android.com/apk/res/android">    <!--     limit-password  设置密码的规则    watch-login 监控屏幕解锁尝试次数    reset-password 更改屏幕解锁密码    force-lock 设备自动锁屏    wipe-data 删除全部的数据         -->    <uses-policies>        <limit-password/>        <watch-login />        <reset-password />        <force-lock />        <wipe-data />    </uses-policies></device-admin>

4.MainActivity代码：

package com.example.lockscreen;import android.app.Activity;import android.app.admin.DevicePolicyManager;import android.content.ComponentName;import android.content.Context;import android.content.Intent;import android.os.Bundle;import android.view.View;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    public void onClick(View v){        // 设备安全管理服务    2.2之前的版本是没有对外暴露的 只能通过反射技术获取          DevicePolicyManager devicePolicyManager = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);                // 申请权限        ComponentName componentName = new ComponentName(this, MyAdmin.class);        // 判断该组件是否有系统管理员的权限        boolean isAdminActive = devicePolicyManager.isAdminActive(componentName);        if(isAdminActive){                        devicePolicyManager.lockNow(); // 锁屏                        devicePolicyManager.resetPassword("123", 0); // 设置锁屏密码//            devicePolicyManager.wipeData(0);  恢复出厂设置  (建议大家不要在真机上测试) 模拟器不支持该操作                    } else {            Intent intent = new Intent();            // 指定动作名称            intent.setAction(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);            // 指定给哪个组件授权            intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, componentName);            startActivity(intent);        }    }}

 注：如果是在2.2版本之前的话，那么必须用反射来解决，

DevicePolicyManager mService = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);Method method = Class.forName("android.os.ServiceManager").getMethod("getService", String.class);IBinder binder = (IBinder) method.invoke(null,new Object[] { Context.DEVICE_POLICY_SERVICE });mService = IDevicePolicyManager.Stub.asInterface(binder);3.注册广播接受者为admin设备ComponentName mAdminName = new ComponentName(this, MyAdmin.class);if (mService != null) {        if (!mService.isAdminActive(mAdminName)) {                    Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);                    intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN,mAdminName);                    startActivity(intent);                }}