通过检查写入文件的权限，确保已获得适当的权限后再保存图像；如果没有权限，则通知用户请求必要的权限。示例：

//确保有适当的权限 if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) { //获得写入权限，然后保存图像 saveImage(bitmap); } else { //如果没有权限，则请求必要的权限 ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CODE_WRITE_EXTERNAL_STORAGE_PERMISSION); }

//在回调中处理权限请求的结果 @Override public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { if (requestCode == REQUEST_CODE_WRITE_EXTERNAL_STORAGE_PERMISSION) { if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { //获得写入权限，然后保存图像 saveImage(bitmap); } else { //如果没有权限，则做出通知或者其他处理 } } }

//实际的保存图像方法 private void saveImage(final Bitmap bitmap) { final String imageName = "my_image.jpg"; final File storageDir = Environment.getExternalStoragePublicDirectory( Environment.DIRECTORY_PICTURES); final File imageFile = new File(storageDir, imageName);

OutputStream out = null;
try {
    out = new FileOutputStream(imageFile);
    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
} catch (FileNotFoundException e) {
    e.printStackTrace();
} finally {
    try {
        if (out != null) {
            out.close();
            Toast.makeText(this, "Image saved to gallery", Toast.LENGTH_SHORT).show();
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

}