Android SharedPreferences，保存简单 int 变量的问题

Question

我正在尝试使用共享首选项保存点击次数，这样当我返回应用程序时，它可以检索最后一个数字，但它在代码中不起作用。谢谢你帮助我。 public class 主要 Activity 扩展 Activity {

private ListView GetAllAreasListView;
private JSONArray jsonArray;
private int AllRequestsCount;
private int i;
private final String AllRequests = "AllRequests";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
 // Restore preferences
    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
     i = prefs.getInt(AllRequests, 0);


    this.GetAllAreasListView = (ListView) this.findViewById(R.id.get_all_areas);

    new GetAllImageTask().execute(new ApiConnector());

    this.GetAllAreasListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
           try
           {
                // GEt the customer which was clicked
               JSONObject customerClicked = jsonArray.getJSONObject(position);

                // Send Customer ID
                Intent showDetails = new Intent(getApplicationContext(),AreaDetailsActivity.class);
                showDetails.putExtra("ImageID", customerClicked.getInt("id"));

                startActivity(showDetails);


                 i = countClick();
                 saveInt();
                System.out.println(i);

         }
         catch (JSONException e)
           {
               e.printStackTrace();
            }
        }
    });

}



public  void setListAdapter(JSONArray jsonArray)
{
    this.jsonArray = jsonArray;
    this.GetAllAreasListView.setAdapter(new GetAllAreasListViewAdapter(jsonArray,this));
}




private class GetAllImageTask extends AsyncTask<ApiConnector,Long,JSONArray>
{
    @Override
    protected JSONArray doInBackground(ApiConnector... params) {

        // it is executed on Background thread

         return params[0].GetAllAreas();
    }

    @Override
    protected void onPostExecute(JSONArray jsonArray) {

        setListAdapter(jsonArray);


    }
}


protected void onResume() {
    super.onResume();

    new GetAllImageTask().execute(new ApiConnector());
}
public int countClick(){
    AllRequestsCount++;
    return(AllRequestsCount);
} 
public void saveInt(){
    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);

    SharedPreferences.Editor editor = prefs.edit();
    editor.putInt(AllRequests,i);
    editor.commit();
}

}

Answer 1

您在 countClick 函数中使用的 AllRequestsCount 变量为空。

只需使用 i++; 而不是 i = countClick();

Android SharedPreferences，保存简单 int 变量的问题

Android SharedPreferences , issue with saving simple int variable

int

android

sharedpreferences