最近再做一个项目，要求unity与原生android混合开发，要求点击unity按钮，android实现录屏功能并将录制内容保存到相册中，实现相册及时刷新，查阅了一下文档，android在5.0之后的api才开放了录屏接口。。。下面是实现：

package com.Xreal.TJYH;

import android.Manifest;
import android.content.ContentValues;
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.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.provider.MediaStore;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.util.DisplayMetrics;
import android.view.KeyEvent;
import android.widget.RelativeLayout;
import android.widget.Toast;

import java.io.File;
import java.io.IOException;

public class u3d extends UnityPlayerActivity {
    private static final int RECORD_REQUEST_CODE  = 101;
    private static final int STORAGE_REQUEST_CODE = 102;
    private static final int AUDIO_REQUEST_CODE   = 103;
    private static final int SHOW = 1;
    private static final int CANCEL = 2;
    private boolean isRecording;
    public static Context currentActivity;
    private RelativeLayout mU3d;
    private MediaProjectionManager mediaProjectionManager;
    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what) {
                case SHOW:
                    if (isRecording){
                        Toast.makeText(u3d.this,"录制已开始",Toast.LENGTH_SHORT).show();
                    }else {
                        startScreenCapture();
                        isRecording = true;
                    }
                    break;
                case CANCEL:
                    if (isRecording){
                        mediaRecorder.stop();
                        mediaRecorder.reset();
                        mediaProjection.stop();
                        virtualDisplay.release();
                        isRecording = false;
                        insertVideoToMediaStore(getSaveDirectory()+videoName);
                        Toast.makeText(u3d.this,"录制结束",Toast.LENGTH_SHORT).show();
                    }else {
                        Toast.makeText(u3d.this,"没有开始录制",Toast.LENGTH_SHORT).show();
                    }
                    break;
            }
        }
    };
    private MediaProjection mediaProjection;
    private MediaRecorder mediaRecorder;
    private VirtualDisplay virtualDisplay;
    /**
     * 屏幕的宽度
     */
    private int screenWidth ;
    /**
     * 屏幕的高度
     */
    private int screenHeight ;
    /**
     * 屏幕的像素
     */
    private int screenDpi;
    private DisplayMetrics metrics;
    /**
     * 保存在相册视频的名字
     */
    private String videoName;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_u3d);
        mediaRecorder = new MediaRecorder();
        metrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(metrics);
        /**
         * 动态注册权限
         */
        if (ContextCompat.checkSelfPermission(u3d.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
                != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this,
                    new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, STORAGE_REQUEST_CODE);
        }
        if (ContextCompat.checkSelfPermission(u3d.this, Manifest.permission.RECORD_AUDIO)
                != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this,
                    new String[] {Manifest.permission.RECORD_AUDIO}, AUDIO_REQUEST_CODE);
        }
        currentActivity = this;
        mU3d = (RelativeLayout) findViewById(R.id.u3d);
        mU3d.addView(mUnityPlayer);
        mUnityPlayer.requestFocus();
    }
    /**
     * unity调用的方法，需要用一个handler进行处理实现功能，直接无法实现。
     */
    public void stopRecordin() {
        mHandler.sendEmptyMessage(CANCEL);
    }
    /**
     * unity调用的方法，需要用一个handler进行处理实现功能，直接无法实现。
     */
    public void startRecording() {
        mHandler.sendEmptyMessage(SHOW);

    }

    private void startScreenCapture() {
        mediaProjectionManager = (MediaProjectionManager) getSystemService(MEDIA_PROJECTION_SERVICE);
        Intent captureIntent = mediaProjectionManager.createScreenCaptureIntent();
        startActivityForResult(captureIntent, RECORD_REQUEST_CODE);
    }

    public void setConfig(int screenWidth, int screenHeight, int screenDpi) {
        this.screenWidth = screenWidth;
        this.screenHeight = screenHeight;
        this.screenDpi = screenDpi;
    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == RECORD_REQUEST_CODE && resultCode == RESULT_OK) {
            mediaProjection = mediaProjectionManager.getMediaProjection(resultCode, data);
            setConfig(metrics.widthPixels,metrics.heightPixels,metrics.densityDpi);
            startRecord();
            Toast.makeText(this, "开始录制", Toast.LENGTH_SHORT).show();
        }
    }

    public boolean startRecord() {
        initRecorder();
        createVirtualDisplay();
        mediaRecorder.start();
        return true;
    }

    private void createVirtualDisplay() {
        virtualDisplay = mediaProjection.createVirtualDisplay("MainScreen", screenWidth, screenHeight, screenDpi,
                DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR, mediaRecorder.getSurface(), null, null);
    }

    private void initRecorder() {
        mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        mediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        videoName = System.currentTimeMillis() + ".mp4";
        mediaRecorder.setOutputFile(getSaveDirectory() + videoName);
        mediaRecorder.setVideoSize(screenWidth, screenHeight);
        mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
        mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        mediaRecorder.setVideoEncodingBitRate(5 * 1024 * 1024);
        mediaRecorder.setVideoFrameRate(30);
        try {
            mediaRecorder.prepare();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public String getSaveDirectory() {
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            String screenRecordPath =  Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "DCIM"+File.separator+"Camera"+File.separator;
            return screenRecordPath;
        } else {
            return null;
        }
    }

    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK){
            mUnityPlayer.quit();
        }
        return super.onKeyUp(keyCode, event);
    }
    public  void insertVideoToMediaStore( String filePath) {
        ContentValues values = new ContentValues();
        values.put(MediaStore.MediaColumns.DATA,filePath);
        // video/*
        values.put(MediaStore.MediaColumns.MIME_TYPE, "video/mp4");
        getContentResolver().insert(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, values);
    }
    /**
     * 打开相册，
     *
     * @return
     */
    public void openAlbum( ){
        Intent intent = new Intent(Intent.ACTION_PICK);
        startActivity(intent);
    }
}