MediaProjection服务在SystemServiceRegistry的静态块里面注册的

@frameworks/base/core/java/android/app/SystemServiceRegistry.javapublic final class SystemServiceRegistry {    private static final String TAG = "SystemServiceRegistry";    /** @hide */    public static boolean sEnableServiceNotFoundWtf = false;    private static int sServiceCacheSize;    private static volatile boolean sInitializing;    // Not instantiable.    private SystemServiceRegistry() { }    static {        registerService(Context.MEDIA_PROJECTION_SERVICE, MediaProjectionManager.class,

申请屏幕录制权限通过启动com.android.systemui/.media.MediaProjectionPermissionActivity来获取权限

requestScreenRecordPermission    Intent captureIntent = u3dClient.createScreenCaptureIntent();        this.mProjectionManager.createScreenCaptureIntent();          //Intent { cmp=com.android.systemui/.media.MediaProjectionPermissionActivity } packagename=com.android.systemui    startActivityForResult(captureIntent, LOCAL_REQUEST_CODE);

@@frameworks/base/packages/SystemUI/src/com/android/systemui/media/MediaProjectionPermissionActivity.java/* * Copyright (C) 2014 The Android Open Source Project * * 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.android.systemui.media;import static android.view.WindowManager.LayoutParams.SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;import android.app.Activity;import android.app.AlertDialog;import android.content.DialogInterface;import android.content.Intent;import android.content.pm.ApplicationInfo;import android.content.pm.PackageManager;import android.graphics.Typeface;import android.media.projection.IMediaProjection;import android.media.projection.IMediaProjectionManager;import android.media.projection.MediaProjectionManager;import android.os.Bundle;import android.os.IBinder;import android.os.RemoteException;import android.os.ServiceManager;import android.text.BidiFormatter;import android.text.SpannableString;import android.text.TextPaint;import android.text.TextUtils;import android.text.style.StyleSpan;import android.util.Log;import android.view.View;import android.view.Window;import android.view.WindowManager;import android.widget.TextView;import com.android.systemui.R;import com.android.systemui.util.Utils;public class MediaProjectionPermissionActivity extends Activity        implements DialogInterface.OnClickListener, DialogInterface.OnCancelListener {    private static final String TAG = "MediaProjectionPermissionActivity";    private static final float MAX_APP_NAME_SIZE_PX = 500f;    private static final String ELLIPSIS = "\u2026";    private String mPackageName;    private int mUid;    private IMediaProjectionManager mService;    private AlertDialog mDialog;    @Override    public void onCreate(Bundle icicle) {	        Log.e(TAG, "xww getprojectionperimssino 1");        super.onCreate(icicle);        mPackageName = getCallingPackage();        IBinder b = ServiceManager.getService(MEDIA_PROJECTION_SERVICE);        mService = IMediaProjectionManager.Stub.asInterface(b);        if (mPackageName == null) {            finish();	        Log.e(TAG, "xww getprojectionperimssino 2");            return;        }        PackageManager packageManager = getPackageManager();        ApplicationInfo aInfo;        try {            aInfo = packageManager.getApplicationInfo(mPackageName, 0);            mUid = aInfo.uid;        } catch (PackageManager.NameNotFoundException e) {            Log.e(TAG, "unable to look up package name", e);            finish();	        Log.e(TAG, "xww getprojectionperimssino 3");            return;        }        try {            if (mService.hasProjectionPermission(mUid, mPackageName)) {                setResult(RESULT_OK, getMediaProjectionIntent(mUid, mPackageName));                finish();	            Log.e(TAG, "xww getprojectionperimssino 4");                return;            } else {                setResult(RESULT_OK, getMediaProjectionIntent(mUid, mPackageName));	            Log.e(TAG, "xww getprojectionperimssino 5");                finish();                return;            }        } catch (RemoteException e) {            Log.e(TAG, "Error checking projection permissions", e);            finish();	        Log.e(TAG, "xww getprojectionperimssino 6");            return;        }    }    @Override    protected void onDestroy() {        super.onDestroy();        if (mDialog != null) {            mDialog.dismiss();        }    }    @Override    public void onClick(DialogInterface dialog, int which) {        try {            if (which == AlertDialog.BUTTON_POSITIVE) {                setResult(RESULT_OK, getMediaProjectionIntent(mUid, mPackageName));            }        } catch (RemoteException e) {            Log.e(TAG, "Error granting projection permission", e);            setResult(RESULT_CANCELED);        } finally {            if (mDialog != null) {                mDialog.dismiss();            }            finish();        }    }    private Intent getMediaProjectionIntent(int uid, String packageName)            throws RemoteException {        IMediaProjection projection = mService.createProjection(uid, packageName,                 MediaProjectionManager.TYPE_SCREEN_CAPTURE, false /* permanentGrant */);        Intent intent = new Intent();        intent.putExtra(MediaProjectionManager.EXTRA_MEDIA_PROJECTION, projection.asBinder());        return intent;    }    @Override    public void onCancel(DialogInterface dialog) {        finish();    }}

最后通过获取Activity的结果判断是否成功获取到屏幕录制权限

public void onActivityResult(int requestCode, int resultCode, Intent data) {        super.onActivityResult(requestCode, resultCode, data);        if (resultCode ！= Activity.RESULT_CANCELED) {            Log.e(TAG, "获取到屏幕录制权限----");            return;        }    }

@@frameworks/base/packages/SystemUI/src/com/android/systemui/media/MediaProjectionPermissionActivity.java

/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * 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.android.systemui.media;

import static android.view.WindowManager.LayoutParams.SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.graphics.Typeface;
import android.media.projection.IMediaProjection;
import android.media.projection.IMediaProjectionManager;
import android.media.projection.MediaProjectionManager;
import android.os.Bundle;
import android.os.IBinder;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.text.BidiFormatter;
import android.text.SpannableString;
import android.text.TextPaint;
import android.text.TextUtils;
import android.text.style.StyleSpan;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.TextView;

import com.android.systemui.R;
import com.android.systemui.util.Utils;

public class MediaProjectionPermissionActivity extends Activity
        implements DialogInterface.OnClickListener, DialogInterface.OnCancelListener {
    private static final String TAG = "MediaProjectionPermissionActivity";
    private static final float MAX_APP_NAME_SIZE_PX = 500f;
    private static final String ELLIPSIS = "\u2026";

    private String mPackageName;
    private int mUid;
    private IMediaProjectionManager mService;

    private AlertDialog mDialog;

    @Override
    public void onCreate(Bundle icicle) {

            Log.e(TAG, "xww getprojectionperimssino 1");
        super.onCreate(icicle);

        mPackageName = getCallingPackage();
        IBinder b = ServiceManager.getService(MEDIA_PROJECTION_SERVICE);
        mService = IMediaProjectionManager.Stub.asInterface(b);

        if (mPackageName == null) {
            finish();
            Log.e(TAG, "xww getprojectionperimssino 2");
            return;
       }

        PackageManager packageManager = getPackageManager();
        ApplicationInfo aInfo;
        try {
            aInfo = packageManager.getApplicationInfo(mPackageName, 0);
            mUid = aInfo.uid;
       } catch (PackageManager.NameNotFoundException e) {
            Log.e(TAG, "unable to look up package name", e);
            finish();
            Log.e(TAG, "xww getprojectionperimssino 3");
            return;
       }

        try {
            if (mService.hasProjectionPermission(mUid, mPackageName)) {
                setResult(RESULT_OK, getMediaProjectionIntent(mUid, mPackageName));
                finish();
                Log.e(TAG, "xww getprojectionperimssino 4");
                return;
           } else {
                setResult(RESULT_OK, getMediaProjectionIntent(mUid, mPackageName));
                Log.e(TAG, "xww getprojectionperimssino 5");
                finish();
                return;
           }
        } catch (RemoteException e) {
            Log.e(TAG, "Error checking projection permissions", e);
            finish();
            Log.e(TAG, "xww getprojectionperimssino 6");
            return;
       }

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mDialog != null) {
            mDialog.dismiss();
       }
    }

    @Override
    public void onClick(DialogInterface dialog, int which) {
        try {
            if (which == AlertDialog.BUTTON_POSITIVE) {
                setResult(RESULT_OK, getMediaProjectionIntent(mUid, mPackageName));
           }
        } catch (RemoteException e) {
            Log.e(TAG, "Error granting projection permission", e);
            setResult(RESULT_CANCELED);
       } finally {
            if (mDialog != null) {
                mDialog.dismiss();
           }
            finish();
        }
    }

    private Intent getMediaProjectionIntent(int uid, String packageName)
            throws RemoteException {
        IMediaProjection projection = mService.createProjection(uid, packageName,
                 MediaProjectionManager.TYPE_SCREEN_CAPTURE, false /* permanentGrant */);
        Intent intent = new Intent();
        intent.putExtra(MediaProjectionManager.EXTRA_MEDIA_PROJECTION, projection.asBinder());
        return intent;
   }

    @Override
    public void onCancel(DialogInterface dialog) {
        finish();
   }
}