Android 屏幕截圖並用WindowManager顯示

• Android屏幕截圖，獲得截圖存儲在SD卡上。

• 所截取的圖，實時顯示在屏幕上。用戶點擊圖片——消失；用戶不點擊，指定時間後——圖片自動消失。

感性認識：

拋磚引玉，詳見註釋：

@Override
public void onClick(View v) {
    switch (v.getId()) {
    case R.id.about_me:
        //獲取屏幕
        View targetView = mActivity.getWindow().getDecorView();
        targetView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_FULLSCREEN);//截全屏
        targetView.setDrawingCacheEnabled(true);
        Bitmap fullBitmap = Bitmap.createBitmap(targetView.getDrawingCache());
        /**獲取狀態欄高度
        Rect frame = new Rect();
        mActivity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
        int statusBarHeight = frame.top;*/
        DisplayMetrics dm = mActivity.getResources().getDisplayMetrics();
        /** 去掉標題欄
        Bitmap bitmap = Bitmap.createBitmap(fullBitmap, 0, statusBarHeight, dm.widthPixels, dm.heightPixels - statusBarHeight);
        targetView.destroyDrawingCache();*/
        OutputStream output = null;
        try {
            if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
                String sdPath = Environment.getExternalStorageDirectory().getPath();//sd卡路徑
                String pngPath = sdPath + "/Remind/";//截圖存放路徑
                File pngDir = new File(pngPath);
                if (!pngDir.exists()) {
                    pngDir.mkdir();//make路徑
                }
                String pngName = pngPath + System.currentTimeMillis() + ".png";
                output = new FileOutputStream(pngName);
                if (output != null) {
                    fullBitmap.compress(Bitmap.CompressFormat.PNG, 100, output);//100%高清大圖
                    output.flush();
                    output.close();
                }
                /** WindowManager */
                LayoutInflater inflater = LayoutInflater.from(mActivity);
                screenShot = inflater.inflate(R.layout.screen_shot, null);
                wmManager =(WindowManager) mActivity.getSystemService(mActivity.WINDOW_SERVICE);
                WindowManager.LayoutParams wmParams = new WindowManager.LayoutParams();
                ImageView shotImg = (ImageView) screenShot.findViewById(R.id.screen_shot_img);
                shotImg.setImageBitmap(targetView.getDrawingCache());
            /**
             *如下都是WindowManager.LayoutParams的相關屬性
             */
               wmParams.type=WindowManager.LayoutParams.TYPE_PRIORITY_PHONE;   //這裏是關鍵
               wmParams.format=PixelFormat.RGBA_8888;
               wmParams.flags=WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                       | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL;
               wmParams.alpha = 0.8f; //透明度
               //WindowManager位置
               wmParams.width = dm.widthPixels * 1 / 2;
               wmParams.height = dm.heightPixels * 1 / 2;
               wmParams.x = dm.widthPixels * 1 / 2;
               wmParams.y = - (dm.heightPixels * 1 / 5);
             //添加View
               wmManager.addView(screenShot, wmParams);
               isRemoved = false;
               //計時器
                timer = new Timer();
                //點擊圖片，消失。
                shotImg.setOnClickListener(new OnClickListener() {
                    @Override
                    public void onClick(View arg0) {
                        if (wmManager != null && !isRemoved) {
                            wmManager.removeView(screenShot);
                            isRemoved = true;
                            if (timer != null) {
                                timer.cancel();
                            }
                        }
                    }
                });
                //定時任務，顯示3秒後自動消失。
                timer.schedule(new TimerTask() {
                    @Override
                    public void run() {
                        if (wmManager != null && !isRemoved) {
                            wmManager.removeView(screenShot);
                            isRemoved = true;
                        }
                    }
                }, 3000);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        break;
    default:
        break;
    }
}