找不到com.android.volley.request的类文件

Question

您好我正在尝试通过

为salesforce开发Android原生应用程序

 Forcedroid Mobile SDK

我的文件或目录如上图所示    

但我的Mainctivity课程中出现两个错误

        private void sendRequest(String soql) throws UnsupportedEncodingException {
    RestRequest restRequest = RestRequest.getRequestForQuery(getString(R.string.api_version), soql);

    client.sendAsync(restRequest, new AsyncRequestCallback() {
        @Override
        public void onSuccess(RestRequest request, RestResponse result) {
            try {
                listAdapter.clear();
                JSONArray records = result.asJSONObject().getJSONArray("records");
                for (int i = 0; i < records.length(); i++) {
                    listAdapter.add(records.getJSONObject(i).getString("Name"));
                }                   
            } catch (Exception e) {
                onError(e);
            }
        }

        @Override
        public void onError(Exception exception) {
            Toast.makeText(MainActivity.this,
                           MainActivity.this.getString(SalesforceSDKManager.getInstance().getSalesforceR().stringGenericError(), exception.toString()),
                           Toast.LENGTH_LONG).show();
        }
    });
}

第一个错误是

  api_version cannot be resolved or is not a field

，第二个错误是

  The type com.android.volley.Request cannot be resolved. It is indirectly referenced from required .class files

我对Android知之甚少，但SalesForce SDK对我来说是新的。甚至单次我都无法运行我创建的应用程序“sfaDroidpp”。请带我离开这个问题。在此先感谢所有人。