无法解析符号'@xml/device_admin'

Question

我正在尝试在Android 5.1设备上实现屏幕固定。 我遇到了这个答案，在尝试向我的清单添加intent-filter时，我收到此错误：Cannot resolve symbol '@xml/device_admin' 。

我认为这是因为xml/device_admin不存在，所以如果是这种情况，我在哪里创建它？

我的清单

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="MY_PACKAGE">
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.app.action.PROFILE_PROVISIONING_COMPLETE" />
            </intent-filter>
        </activity>
        <receiver
            android:name=".MyDeviceAdminReceiver"
            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" />
            <intent-filter>
                <action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
            </intent-filter>
        </receiver>
        <!-- <receiver android:name=".BootReceiver"> -->
        <!-- <intent-filter > -->
        <!-- <action android:name="android.intent.action.BOOT_COMPLETED"/> -->
        <!-- </intent-filter> -->
        <!-- </receiver> -->
    </application>
</manifest>

我的主要活动

package MY_PACKAGE;
import android.content.ComponentName;
import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.app.admin.*;
public class MainActivity extends AppCompatActivity {
    private WebView mWebView;
    private static final String TAG = "MainActivity";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ComponentName deviceAdmin = new ComponentName(this, MyDeviceAdminReceiver.class);
        DevicePolicyManager mDpm = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);
        mWebView = (WebView) findViewById(R.id.activity_main_webview);
        // Enable Javascript
        WebSettings webSettings = mWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        mWebView.setWebViewClient(new WebViewClient());
        mWebView.loadUrl("my_website.com"); //Note that this is a placeholder website.
        if (mDpm.isDeviceOwnerApp(getPackageName())) {
            mDpm.setLockTaskPackages(deviceAdmin, new String[]{getPackageName()});
        }
        if (mDpm.isLockTaskPermitted(this.getPackageName()))
            startLockTask();
//        try {
//            Runtime.getRuntime().exec("dpm set-device-owner MY_PACKAGE/.MyDeviceAdminReceiver");
//        } catch (Exception e) {
//            Log.e(TAG, "device owner not set");
//            Log.e(TAG, e.toString());
//            e.printStackTrace();
//        }
        try {
            startLockTask();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    @Override
    public void onBackPressed() {
        if(mWebView.canGoBack()) {
            mWebView.goBack();
        } else {
            System.out.print("LOCKED IN PLACE!");
        }
    }

}

Answer 1

我认为这是因为 xml/device_admin 不存在，所以如果这是 案例，我在哪里创建它？

在层次结构中创建文件夹application/src/main/res/xml将文件device_admin.xml保留在此 XML 文件夹中

device_admin.xml文件的结构是

<device-admin xmlns:android="http://schemas.android.com/apk/res/android">
  <uses-policies>
    <limit-password />
    <watch-login />
    <reset-password />
    <force-lock />
    <wipe-data />
    <expire-password />
    <encrypted-storage />
    <disable-camera />
  </uses-policies>
</device-admin>

Device_admin准则