class BitmapSave {

     fun save(context:Context, inputStream: InputStream, file:File, fileName: String = "shareQChanger.jpg"){
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
            saveBitmap2SelfDirectory(inputStream,file,fileName)
            val values = ContentValues()
            values.put(MediaStore.Images.Media.DATA, 
 
"${file.absolutePath}/$fileName")
            values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg")
            val uri: Uri? = context.contentResolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)
            val intent = Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE)
            intent.data 
 
= uri
            context.sendBroadcast(intent)
        } else {
            val values = ContentValues()
            values.put(MediaStore.Images.Media.DESCRIPTION, "This is an qr image")
            values.put(MediaStore.Images.Media.DISPLAY_NAME, fileName)
            values.put(MediaStore.Images.Media.MIME_TYPE, 
 
"image/jpeg")
            values.put(MediaStore.Images.Media.TITLE, "Image.jpg")
            values.put(MediaStore.Images.Media.RELATIVE_PATH, "Pictures/")
            val external = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
            val resolver: ContentResolver = context.contentResolver
            val insertUri = resolver.insert(external, values)
            var os: OutputStream? = null
            try {
                if (insertUri != null) {
                    os = resolver.openOutputStream(insertUri)
                }
                if (os != null) {
                    val buffer = ByteArray(1024 * 4)
                    var len: Int
                    while (inputStream.read(buffer).also { len = it } != -1) {
                        os.write(buffer, 0, len)
                    }
                    os.flush()
                }
            } catch (e: IOException) {
                e.printStackTrace()
            } finally {
                os?.close()
                inputStream.close()
            }
        }
    }

    //儲存圖片至app私有目錄
    private fun saveBitmap2SelfDirectory(inputStream: InputStream, fileDirectory: File, fileName: String) {
        var file: File? = null
        file = File(fileDirectory, fileName)
        try {
            val fos = FileOutputStream(file)
//            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos)
            val buffer = ByteArray(1024 * 4)
            var len: Int
            while (inputStream.read(buffer).also { len = it } != -1) {
                fos.write(buffer, 0, len)
            }
            inputStream.close()
            fos.flush()
            fos.close()
        } catch (e: FileNotFoundException) {
            e.printStackTrace()
        } catch (e: IOException) {
            e.printStackTrace()
        }
    }
}

使用

val file = getExternalFilesDir(Environment.DIRECTORY_PICTURES)
BitmapSave().save(baseContext,resources.openRawResource(R.mipmap.share),file)