Android 为什么图像不保存在sd卡中

如何在android中拍摄屏幕截图

他们正在工作，但也没有在SD卡上保存屏幕短图像

public class MainActivity extends AppCompatActivity {

private Button take;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    take= (Button) findViewById(R.id.take);

    take.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            takeScreenshot();
        }
    });

}

private void takeScreenshot() {
    Date now = new Date();
    android.text.format.DateFormat.format("yyyy-MM-dd_hh:mm:ss", now);

    try {
        // image naming and path  to include sd card  appending name you choose for file
        String mPath = Environment.getExternalStorageDirectory().toString() + "/PICTURES/Screenshots/" + now + ".jpg";

        // create bitmap screen capture
        View v1 = getWindow().getDecorView().getRootView();
        v1.setDrawingCacheEnabled(true);
        Bitmap bitmap = Bitmap.createBitmap(v1.getDrawingCache());
        v1.setDrawingCacheEnabled(false);
        File imageFile = new File(mPath);
        FileOutputStream outputStream = new FileOutputStream(imageFile);
        int quality = 100;
        bitmap.compress(Bitmap.CompressFormat.JPEG, quality, outputStream);
        outputStream.flush();
        outputStream.close();


        MediaScannerConnection.scanFile(this,
                new String[]{imageFile.toString()}, null,
                new MediaScannerConnection.OnScanCompletedListener() {
                    public void onScanCompleted(String path, Uri uri) {
                        Log.i("ExternalStorage", "Scanned " + path + ":");
                        Log.i("ExternalStorage", "-> uri=" + uri);
                    }
                });

        openScreenshot(imageFile);
    } catch (Throwable e) {
        // Several error may come out with file handling or OOM
        e.printStackTrace();
    }
}

private void openScreenshot(File imageFile) {
    Intent intent = new Intent();
    intent.setAction(Intent.ACTION_VIEW);
    Uri uri = Uri.fromFile(imageFile);
    intent.setDataAndType(uri, "image/*");
    startActivity(intent);
   }

}

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另外，请告诉我如何在android中在视频视图中进行屏幕截图

权限？是否存在错误日志？权限？是否存在错误日志？