为什么isLockTaskPermitted标志为false

Question

我正试图在Android L上以编程方式固定屏幕.我的应用程序包含xml文件

<?xml version="1.0" encoding="utf-8"?>
<device-admin xmlns:android="http://schemas.android.com/apk/res/android">
    <uses-policies>
        <force-lock/>
        <watch-login/>
        <disable-camera/>
        <disable-keyguard-features/>
        <encrypted-storage/>
        <expire-password/>
        <limit-password/>
        <reset-password/>
        <set-global-proxy/>
        <wipe-data/>
    </uses-policies>
</device-admin>

我在AndroidManifest文件中使用正确的行安装了应用程序,我在其中定义了AdminReceiver.几周前一切都运转良好,但现在当我回到这个项目时 - 应用程序让我每次应用程序启动时都要确认"Pin屏幕"弹出窗口.

当我调试,我注意到怪异的行为 devicePolicyManager.isAdminActive(componentName)是真实的 devicePolicyManager.isDeviceOwnerApp(getPackageName())是真实的

但

devicePolicyManager.isLockTaskPermitted(getPackageName()) 是假的

如果我使用adb dpm set-device-owner ...commend 将app设置为设备所有者或将device_owner.xml文件推送到/ data/system/并不重要

我的问题是为什么应用程序没有锁定屏幕的权限？

Answer 1

为此，您必须调用setLockTaskPackages()

您的代码应该如下所示。

您的活动应该有

ComponentName mAdminComponentName = DeviceAdminReceiver.getComponentName(this);
//where this will be your Activity

DevicePolicyManager mDevicePolicyManager = (DevicePolicyManager)
                getSystemService(Context.DEVICE_POLICY_SERVICE);

mDevicePolicyManager.setLockTaskPackages(mAdminComponentName,new String[]{getPackageName()});

DeviceAdminReceiver.java

// Copyright 2016 Google Inc.
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//      http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.codelabs.cosu;

/**
 * Created by nyfuchs on 4/26/16.
 */

import android.content.ComponentName;
import android.content.Context;

/**
 * Handles events related to the managed profile.
 */
public class DeviceAdminReceiver extends android.app.admin.DeviceAdminReceiver {
    private static final String TAG = "DeviceAdminReceiver";

    /**
     * @param context The context of the application.
     * @return The component name of this component in the given context.
     */
    public static ComponentName getComponentName(Context context) {
        return new ComponentName(context.getApplicationContext(), DeviceAdminReceiver.class);
    }
}

AndroidManifest.xml

    <receiver
        android:name="com.google.codelabs.cosu.DeviceAdminReceiver"
        android:description="@string/app_name"
        android:label="@string/app_name"
        android:permission="android.permission.BIND_DEVICE_ADMIN">
        <meta-data
            android:name="android.app.device_admin"
            android:resource="@xml/device_admin_receiver" />
        <intent-filter>
            <action android:name="android.intent.action.DEVICE_ADMIN_ENABLED"/>
            <action android:name="android.intent.action.PROFILE_PROVISIONING_COMPLETE"/>
            <action android:name="android.intent.action.BOOT_COMPLETED"/>
        </intent-filter>
    </receiver>