将文件写入android中的存储卡不起作用

我无法使用以下代码在外部存储卡上写入图像

private  File getOutputMediaFileToExternalMemory(int type){

     String state = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED.equals(state)) {
         Toast.makeText(context,  "SD CARD IS MOUNTED", Toast.LENGTH_SHORT).show();

    } else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
        Toast.makeText(context,  "SD CARD IS READ ONLY", Toast.LENGTH_SHORT).show();

    }else{
        Toast.makeText(context,  "OTHR SD card error", Toast.LENGTH_SHORT).show();
    }
      String fullPath = Environment.getExternalStorageDirectory()
              .getAbsolutePath();



     File mediaStorageDir = new File(fullPath + "/saved_Amith_images");    

    if (! mediaStorageDir.exists()){
        if (! mediaStorageDir.mkdirs()){
            Log.d("MyCameraApp", "failed to create directory");
            return null;
        }
    }

    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    File mediaFile;
    if (type == MEDIA_TYPE_IMAGE){
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
        "IMG_"+ timeStamp+"Amith" + ".jpg");
    } else if(type == MEDIA_TYPE_VIDEO) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
        "VID_"+ timeStamp + ".mp4");
    } else {
        return null;
    }

    return mediaFile;
}



    private PictureCallback mPicture = new PictureCallback() {

    @Override
    public void onPictureTaken(byte[] data, Camera camera) {

        File pictureFile = getOutputMediaFileToExternalMemory(MEDIA_TYPE_IMAGE);
        if (pictureFile == null){
              Toast.makeText(context, "Error creating media file, check storage permissions:", Toast.LENGTH_SHORT).show();
            Log.d(TAG, "Error creating media file, check storage permissions: ");
            return;
        }else{
             Toast.makeText(context, "Save: Pic file is found going to write", Toast.LENGTH_SHORT).show();
        }

        try {
            FileOutputStream fos = new FileOutputStream(pictureFile);
            fos.write(data);
            fos.close();
            Toast.makeText(context, "Save: Pic is saved successfully", Toast.LENGTH_SHORT).show();
        } catch (FileNotFoundException e) {
              Toast.makeText(context,  "File not found: " + e.getMessage(), Toast.LENGTH_LONG).show();
            Log.d(TAG, "File not found: " + e.getMessage());
        } catch (IOException e) {
             Toast.makeText(context,  "Error accessing file: " + e.getMessage(), Toast.LENGTH_LONG).show();
            Log.d(TAG, "Error accessing file: " + e.getMessage());
        }catch (Exception e) {
             Toast.makeText(context,  "Other Exception: " + e.getMessage(), Toast.LENGTH_LONG).show();
        }
    }
};

它会写入sd卡（手机内部存储器）。我想将图像写入安装在手机中的外部存储卡

当安装了SD卡时，我得到了

Toast

我已经设定了权限

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

---

在清单

中，请注意此代码没有写入。是的，我已更新了Que plz。请查看目录是否存在？如果目录不存在，我们将创建一个新目录。我可以轻松读取该目录。我的问题是。目录创建失败了吗？这里有什么问题？