android 录屏

录屏，google了一下，记录下来，以免翻墙

android 4.4 录屏可通过adb:adb shell screenrecord /sdcard/video.mp4 （未测试）

android 5.0：开始提供了屏幕录制api了（https://developer.android.com/about/versions/android-5.0#UI）

大概：

MediaProjectionManager是一个系统服务，通过他最终创建VirtualDisplay,创建时将MediaRecorder的Surface提供给VirtualDisplay

代码来源：https://www.truiton.com/2015/05/capture-record-android-screen-using-mediaprojection-apis/

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.RECORD_AUDIO"/>

　　

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                xmlns:tools="http://schemas.android.com/tools"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="#FFFFFF"
                android:paddingBottom="@dimen/activity_vertical_margin"
                android:paddingLeft="@dimen/activity_horizontal_margin"
                android:paddingRight="@dimen/activity_horizontal_margin"
                android:paddingTop="@dimen/activity_vertical_margin"
                tools:context=".MainActivity">


    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="10dp"
        android:text="Recording Status: "
        android:textAppearance="?android:attr/textAppearanceLarge"/>

    <ToggleButton
        android:id="@+id/toggle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="5dp"
        android:text="Start"/>

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="150dp"
        android:layout_height="150dp"
        android:layout_below="@+id/toggle"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="85dp"
        android:src="@mipmap/truiton_short"/>
</RelativeLayout>

　　

package com.truiton.screencapture;

import android.Manifest;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.hardware.display.DisplayManager;
import android.hardware.display.VirtualDisplay;
import android.media.MediaRecorder;
import android.media.projection.MediaProjection;
import android.media.projection.MediaProjectionManager;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.Settings;
import android.support.annotation.NonNull;
import android.support.design.widget.Snackbar;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.SparseIntArray;
import android.view.Surface;
import android.view.View;
import android.widget.Toast;
import android.widget.ToggleButton;

import java.io.IOException;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";
    private static final int REQUEST_CODE = 1000;
    private int mScreenDensity;
    private MediaProjectionManager mProjectionManager;
    private static final int DISPLAY_WIDTH = 720;
    private static final int DISPLAY_HEIGHT = 1280;
    private MediaProjection mMediaProjection;
    private VirtualDisplay mVirtualDisplay;
    private MediaProjectionCallback mMediaProjectionCallback;
    private ToggleButton mToggleButton;
    private MediaRecorder mMediaRecorder;
    private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
    private static final int REQUEST_PERMISSIONS = 10;

    static {
        ORIENTATIONS.append(Surface.ROTATION_0, 90);
        ORIENTATIONS.append(Surface.ROTATION_90, 0);
        ORIENTATIONS.append(Surface.ROTATION_180, 270);
        ORIENTATIONS.append(Surface.ROTATION_270, 180);
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        DisplayMetrics metrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(metrics);
        mScreenDensity = metrics.densityDpi;

        mMediaRecorder = new MediaRecorder();

        mProjectionManager = (MediaProjectionManager) getSystemService
                (Context.MEDIA_PROJECTION_SERVICE);

        mToggleButton = (ToggleButton) findViewById(R.id.toggle);
        mToggleButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (ContextCompat.checkSelfPermission(MainActivity.this,
                        Manifest.permission.WRITE_EXTERNAL_STORAGE) + ContextCompat
                        .checkSelfPermission(MainActivity.this,
                                Manifest.permission.RECORD_AUDIO)
                        != PackageManager.PERMISSION_GRANTED) {
                    if (ActivityCompat.shouldShowRequestPermissionRationale
                            (MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) ||
                            ActivityCompat.shouldShowRequestPermissionRationale
                                    (MainActivity.this, Manifest.permission.RECORD_AUDIO)) {
                        mToggleButton.setChecked(false);
                        Snackbar.make(findViewById(android.R.id.content), R.string.label_permissions,
                                Snackbar.LENGTH_INDEFINITE).setAction("ENABLE",
                                new View.OnClickListener() {
                                    @Override
                                    public void onClick(View v) {
                                        ActivityCompat.requestPermissions(MainActivity.this,
                                                new String[]{Manifest.permission
                                                        .WRITE_EXTERNAL_STORAGE, Manifest.permission.RECORD_AUDIO},
                                                REQUEST_PERMISSIONS);
                                    }
                                }).show();
                    } else {
                        ActivityCompat.requestPermissions(MainActivity.this,
                                new String[]{Manifest.permission
                                        .WRITE_EXTERNAL_STORAGE, Manifest.permission.RECORD_AUDIO},
                                REQUEST_PERMISSIONS);
                    }
                } else {
                    onToggleScreenShare(v);
                }
            }
        });
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode != REQUEST_CODE) {
            Log.e(TAG, "Unknown request code: " + requestCode);
            return;
        }
        if (resultCode != RESULT_OK) {
            Toast.makeText(this,
                    "Screen Cast Permission Denied", Toast.LENGTH_SHORT).show();
            mToggleButton.setChecked(false);
            return;
        }
        mMediaProjectionCallback = new MediaProjectionCallback();
        mMediaProjection = mProjectionManager.getMediaProjection(resultCode, data);
        mMediaProjection.registerCallback(mMediaProjectionCallback, null);
        mVirtualDisplay = createVirtualDisplay();
        mMediaRecorder.start();
    }

    public void onToggleScreenShare(View view) {
        if (((ToggleButton) view).isChecked()) {
            initRecorder();
            shareScreen();
        } else {
            mMediaRecorder.stop();
            mMediaRecorder.reset();
            Log.v(TAG, "Stopping Recording");
            stopScreenSharing();
        }
    }

    private void shareScreen() {
        if (mMediaProjection == null) {
            startActivityForResult(mProjectionManager.createScreenCaptureIntent(), REQUEST_CODE);
            return;
        }
        mVirtualDisplay = createVirtualDisplay();
        mMediaRecorder.start();
    }

    private VirtualDisplay createVirtualDisplay() {
        return mMediaProjection.createVirtualDisplay("MainActivity",
                DISPLAY_WIDTH, DISPLAY_HEIGHT, mScreenDensity,
                DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR,
                mMediaRecorder.getSurface(), null /*Callbacks*/, null
                /*Handler*/);
    }

    private void initRecorder() {
        try {
            mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
            mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
            mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
            mMediaRecorder.setOutputFile(Environment
                    .getExternalStoragePublicDirectory(Environment
                            .DIRECTORY_DOWNLOADS) + "/video.mp4");
            mMediaRecorder.setVideoSize(DISPLAY_WIDTH, DISPLAY_HEIGHT);
            mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
            mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
            mMediaRecorder.setVideoEncodingBitRate(512 * 1000);
            mMediaRecorder.setVideoFrameRate(30);
            int rotation = getWindowManager().getDefaultDisplay().getRotation();
            int orientation = ORIENTATIONS.get(rotation + 90);
            mMediaRecorder.setOrientationHint(orientation);
            mMediaRecorder.prepare();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private class MediaProjectionCallback extends MediaProjection.Callback {
        @Override
        public void onStop() {
            if (mToggleButton.isChecked()) {
                mToggleButton.setChecked(false);
                mMediaRecorder.stop();
                mMediaRecorder.reset();
                Log.v(TAG, "Recording Stopped");
            }
            mMediaProjection = null;
            stopScreenSharing();
        }
    }

    private void stopScreenSharing() {
        if (mVirtualDisplay == null) {
            return;
        }
        mVirtualDisplay.release();
        //mMediaRecorder.release(); //If used: mMediaRecorder object cannot
        // be reused again
        destroyMediaProjection();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        destroyMediaProjection();
    }

    private void destroyMediaProjection() {
        if (mMediaProjection != null) {
            mMediaProjection.unregisterCallback(mMediaProjectionCallback);
            mMediaProjection.stop();
            mMediaProjection = null;
        }
        Log.i(TAG, "MediaProjection Stopped");
    }

    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           @NonNull String permissions[],
                                           @NonNull int[] grantResults) {
        switch (requestCode) {
            case REQUEST_PERMISSIONS: {
                if ((grantResults.length > 0) && (grantResults[0] +
                        grantResults[1]) == PackageManager.PERMISSION_GRANTED) {
                    onToggleScreenShare(mToggleButton);
                } else {
                    mToggleButton.setChecked(false);
                    Snackbar.make(findViewById(android.R.id.content), R.string.label_permissions,
                            Snackbar.LENGTH_INDEFINITE).setAction("ENABLE",
                            new View.OnClickListener() {
                                @Override
                                public void onClick(View v) {
                                    Intent intent = new Intent();
                                    intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                                    intent.addCategory(Intent.CATEGORY_DEFAULT);
                                    intent.setData(Uri.parse("package:" + getPackageName()));
                                    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                                    intent.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
                                    intent.addFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
                                    startActivity(intent);
                                }
                            }).show();
                }
                return;
            }
        }
    }
}