Android解析 - 無法解析符號'FindCallBack'

Question

我想查詢解析數據庫並得到錯誤：無法解析符號'FindCallBack'。 我試過使用'query.find'，但我被告知'findInBackground'更有效。 主要目標是查詢信息並迭代列表以供將來使用。 當我使用'query.find'時，查詢本身起作用，但迭代失敗，就像我試圖訪問無效字段一樣。

'FindCallBack' 版本

import com.parse.Parse; 
import com.parse.ParseObject; 
import com.parse.ParseQuery; 
import com.parse.SaveCallback; 
import com.parse.ParseException; 
import com.parse.FindCallback; 


import java.util.Calendar; 
import java.util.Date; 
import java.text.SimpleDateFormat; 
import java.util.List; 

public class ListNodeActivity extends AppCompatActivity 
{ 
    private Task t = new Task(); 
    private Spinner spin; 
    private Spinner empolyeeSpinner; 
    private int task_id=1; 
    private String time_Date_str = null; 
    private Locations returned_selc_loc; 
    private EditText loc; 

    private ParseObject parse_task=null; 
    private DBManager dbm; 

    private static final int ACTIVITY_SELECT_LOCATION = 0; 
    private ParseObject team_members = null; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_list_node); 
     Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 

     //check is username & password exist 
     ParseQuery<ParseObject> query = new ParseQuery<ParseObject>("OTSUser"); 
     query.whereContains("TeamName", Globals.team_name); 
     query.whereEqualTo("IsManager",0); 

     query.findInBackground(new FindCallBack<ParseObject>() { 
      public void done(List<ParseObject> usrs;ParseException e) { 
       if (e == null) { 
        for (int i = 0; i < usrs.size(); i++) { 
         Log.w("debug", usrs.get(i).getString("Userame")); 
        } 
       } else {//handle the error 
       } 
      } 
     }); 
    } 
} 

'query.find' 版本

//check is username & password exist 
ParseQuery<ParseObject> query = new ParseQuery<ParseObject>("OTSUser"); 
query.whereContains("TeamName", Globals.team_name); 
query.whereEqualTo("IsManager",0); 
List<ParseObject> usrs=null; 

try { 
    usrs = query.find(); 
    Log.w("debug","size of usrs "+usrs.size()); 
    for (int i = 0; i < usrs.size(); i++) 
    { 
    // empolyeeSpinnerAdapter.add(usrs.get(i).getString("Userame")); 
     Log.w("debug",usrs.get(i).getString("Userame")); 
    } 
} catch (ParseException e) {} 

Answer 1

你有兩個錯別字導致此失敗。首先，班級名稱是FindCallback，小寫字母'b'。

您還在使用';'而不是'，'來分開done(...)方法中的參數。將方法更改爲以下內容，並且應該在途中。

query.findInBackground(new FindCallback<ParseObject>() { 
    public void done(List<ParseObject> usrs, ParseException e) { 
     if (e == null) { 
      for (int i = 0; i < usrs.size(); i++) { 
       Log.w("debug", usrs.get(i).getString("Userame")); 
      } 
     } else {//handle the error 
     } 
    } 
});