[移动开发]Android WebView截屏空白或者一片黑如何解决？使用MediaProjection截图。

直接上代码：

入口方法: startTakeScreenShot()

出口方法：返回的Bitmap对象在onActivityResult()? 有todo的注释

注意：该截屏方式 在 build.gradle属性 stargetSdk >=30 的情况下会报错。我这边是28。

    
    val EVENT_SCREENSHOT = 22 //截图事件
    private var mediaProjectionManager: MediaProjectionManager? = null
    private var mediaProjection: MediaProjection? = null
    private var image: Image? = null
    // 开始截屏方法
    fun startTakeScreenShot() {
        mediaProjectionManager =
            application.getSystemService(MEDIA_PROJECTION_SERVICE) as MediaProjectionManager
        startActivityForResult(
            mediaProjectionManager!!.createScreenCaptureIntent(),
            EVENT_SCREENSHOT
        )
    }

    @SuppressLint("WrongConstant")
    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        if (resultCode == RESULT_OK && requestCode == REQUEST_CODE_PIC) {
            if (data != null) {
                val pathList: List<String>? =
                    data.getStringArrayListExtra(Repair_ImgSelActivity.INTENT_RESULT)
                doPicDataS(pathList)
            }
        }
        if (requestCode == EVENT_SCREENSHOT) {
            super.onActivityResult(requestCode, resultCode, data)
            Log.e("whh0914", "captureScreen...")
            val displayMetrics = DisplayMetrics()
            val windowManager = this.getSystemService(WINDOW_SERVICE) as WindowManager
            windowManager.defaultDisplay.getMetrics(displayMetrics)
            val width = displayMetrics.widthPixels
            val height = displayMetrics.heightPixels
            val mImageReader: ImageReader =
                ImageReader.newInstance(width, height, PixelFormat.RGBA_8888, 2)
            mediaProjection = mediaProjectionManager?.getMediaProjection(resultCode, data!!)
            val virtualDisplay = mediaProjection?.createVirtualDisplay(
                "screen-mirror",
                width,
                height,
                displayMetrics.densityDpi,
                DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR,
                mImageReader.surface,
                null,
                null
            )
            Handler().postDelayed(Runnable {
                try {
                    image = mImageReader.acquireLatestImage()
                    if (image != null) {
                        val planes: Array<Image.Plane> = image!!.planes
                        val buffer: ByteBuffer = planes[0].buffer
                        val width: Int = image!!.width
                        val height: Int = image!!.height
                        val pixelStride: Int = planes[0].pixelStride
                        val rowStride: Int = planes[0].rowStride
                        val rowPadding = rowStride - pixelStride * width
                        var bitmap = Bitmap.createBitmap(
                            width + rowPadding / pixelStride,
                            height,
                            Bitmap.Config.ARGB_8888
                        )
                        bitmap!!.copyPixelsFromBuffer(buffer)
                        bitmap =
                            Bitmap.createScaledBitmap(bitmap, bitmap.width, bitmap.height, false)
                        val pipelineFragment = viewPagerAdapter.fragmentList[1] as PipelineFragment
                        pipelineFragment.mWebView.visibility = View.GONE
                        if (bitmap != null) {
                            // 这里获取到截到的Bitmap对象
                            // 下面是将bitmap保存到SD卡中的方法：如有需要请参考博客：https://blog.csdn.net/qq_39731011/article/details/123640342 如不需要请删除
                            ImageSaveUtil.saveAlbum(this,bitmap,
                                Bitmap.CompressFormat.JPEG, 80, true)

                        }
                        bitmap.recycle()
                    }
                } catch (e: java.lang.Exception) {
                    Log.e("截图", "出现异常：$e")
                } finally {
                    if (image != null) {
                        image!!.close()
                    }
                    if (mImageReader != null) {
                        mImageReader.close()
                    }
                    virtualDisplay?.release()
                    //该代码为了避免出现BufferQueueProducer: [ImageReader] dequeueBuffer: BufferQueue has been abandoned
                    mImageReader.setOnImageAvailableListener(null, null)
                    mediaProjection?.stop()
                }
            }, 300)//这里的延迟是为了 不截取到 系统提示是否允许录屏的弹框，可自行调整，经深海测试一般100-500为最佳
        }
    }