Question

我正在开发一个评估派对的应用程序，我为了娱乐和开发目的而投入其他一些东西。我决定基于listViews的许多示例来设计它。 Feed显示在相应的建筑物名称上，当激活onclicklistener时，此菜单会弹出 enter image description here

目前，我只是希望派对的分数根据星数增加。出于某种原因，只有Sig nu是在8个frat页面中的任何一个中更新的。

enter image description here

这是我正在尝试修复的java和xml文件的代码。

Beta_Activity.java

package com.example.weekly;

import java.util.ArrayList;
import java.util.List;
import android.app.ActionBar;
import android.app.ActionBar.OnNavigationListener;
import android.app.Dialog;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.AdapterContextMenuInfo;
import com.parse.Parse;
import com.parse.ParseACL;
import com.parse.ParseException;
import com.parse.ParseObject;
import com.parse.ParseQuery;
import com.parse.ParseUser;

public class Beta_Activity extends ListActivity implements OnNavigationListener {

private List<ParseObject> todos;
private Dialog progressDialog;

private class RemoteDataTask extends AsyncTask<Void, Void, Void> {

    // Override this method to do custom remote calls

    protected Void doInBackground(Void... params) {
        // Gets the current list of todos in sorted order
        ParseQuery<ParseObject> query = new ParseQuery<ParseObject>("Todo");
        query.orderByDescending("_created_at");

        try {
            todos = query.find();
        } catch (ParseException e) {

        }
        return null;
    }

    @Override
    protected void onPreExecute() {
        Beta_Activity.this.progressDialog = ProgressDialog.show(Beta_Activity.this, "", "Loading...", true);
        progressDialog.setCancelable(true);
        super.onPreExecute();
    }

    @Override
    protected void onProgressUpdate(Void... values) {
        super.onProgressUpdate(values);
    }

    @Override
    protected void onPostExecute(Void result) {
        // Put the list of todos into the list view
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(Beta_Activity.this, R.layout.event_row);

        if (todos != null) {
            for (ParseObject todo : todos) {

            //this is the two stage process of singling out parties
            //first you retrieve a string within the name catagory
            //then you evaluate if it equals the house or somehting specific

            String s = todo.get("FratName").toString();
            if(s.equalsIgnoreCase("Beta")){
               adapter.add((String) todo.get("name"));
             } 
           }
        }
        setListAdapter(adapter);
        Beta_Activity.this.progressDialog.dismiss();
        TextView empty = (TextView) findViewById(android.R.id.empty);
        empty.setVisibility(View.VISIBLE);
    }
}

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.ato_listview);

    Parse.initialize(this, "00ICYaClgas8tcY133cCfAui8NUdlhfrE9RdXhHT", "hqzMmKQziHTqtuKw8C1j5oeArkyTdtZPX8aOeVXP");

    ParseUser.enableAutomaticUser();
    ParseACL defaultACL = new ParseACL();
    // Optionally enable public read access.
    defaultACL.setPublicReadAccess(true);
    /*
     * This code above is crucial in making everything work.
     */
    ParseACL.setDefaultACL(defaultACL, true);

    final ActionBar actionBar = getActionBar();
    actionBar.setDisplayShowTitleEnabled(true);
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);
    ArrayList<String> itemList = new ArrayList<String>();

    itemList.add("Beta");
    itemList.add("Home");
    itemList.add("Map");
    itemList.add("ATO");
    itemList.add("Delt");
    itemList.add("Fiji");
    itemList.add("Phi Delt");
    itemList.add("Phi Psi");
    itemList.add("Sig Chi");
    itemList.add("Sig Nu");
    itemList.add("University");
    itemList.add("Login/Create");

    ArrayAdapter<String> aAdpt = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, android.R.id.text1, itemList);
    actionBar.setListNavigationCallbacks(aAdpt, this);

    TextView empty = (TextView) findViewById(android.R.id.empty);
    empty.setVisibility(View.INVISIBLE);

    new RemoteDataTask().execute();
    registerForContextMenu(getListView());
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
//      super.onActivityResult(requestCode, resultCode, intent);
//      if (intent == null) {
//          return;
//      }
//      final Bundle extras = intent.getExtras();
//
//      switch (requestCode) {
//      case 0:
//          new RemoteDataTask() {
//              protected Void doInBackground(Void... params) {
//                  String name = extras.getString("name");
//                  ParseObject todo = new ParseObject("Todo");
//                  todo.put("name", name);
//                  try {
//                      todo.save();
//                  } catch (ParseException e) {
//                  }
//
//                  super.doInBackground();
//                  return null;
//              }
//          }.execute();
//          break;
//      case 1:
//          // Edit the remote object
//          final ParseObject todo;
//          todo = todos.get(extras.getInt("position"));
//          todo.put("name", extras.getString("name"));
//
//          new RemoteDataTask() {
//              protected Void doInBackground(Void... params) {
//                  try {
//                      todo.save();
//                  } catch (ParseException e) {
//                  }
//                  super.doInBackground();
//                  return null;
//              }
//          }.execute();
//          break;
//      }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    boolean result = super.onCreateOptionsMenu(menu);
    menu.add(0, 1, 0, "Refresh");
    return result;
}

@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
    super.onCreateContextMenu(menu, v, menuInfo);
    menu.setHeaderTitle("Rate The party! * = dead, ***** = Amazing");  
    menu.add(0, 1, 0, "*");  
    menu.add(0, 2, 0, "**");
    menu.add(0, 3, 0, "***");
    menu.add(0, 4, 0, "****");
    menu.add(0, 5, 0, "*****");
}

@Override
public boolean onContextItemSelected(MenuItem item) {
    //handling the stars 
    int intScore = 0;
    String prevScore = "";

    if(item.getTitle().equals("*")){

            AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
            Log.d("AdapterContextMenuInfo", "it's: " + info.position);

            ParseObject todo = todos.get(info.position);

            //get the frat score
            prevScore = todo.get("FratScore").toString();
            Log.d("FratScore", "Score: " + prevScore);

            //parse the integer value from string to int
            intScore = Integer.parseInt(prevScore);

            //increment by 1
            intScore = intScore + 1;

            //change back to a string
            String newScore = String.valueOf(intScore);

            //save the parse object value here
            todo.put("FratScore", newScore);
            todo.saveInBackground(); //something goes wrong here

            intScore = 0;   
        //two stars
        }
    if(item.getTitle().equals("**")){

            AdapterContextMenuInfo info2 = (AdapterContextMenuInfo) item.getMenuInfo();
            ParseObject todo2 = todos.get(info2.position);

            //get the frat score
            String prevScore2 = todo2.get("FratScore").toString();

            //parse the integer value from string to int
            int intScore2 = Integer.parseInt(prevScore2);

            //increment by 2
            intScore2 = intScore2 + 2;

            //change back to a string
            String newScore2 = String.valueOf(intScore2);

            //save the parse object value here
            todo2.put("FratScore", newScore2);
            todo2.saveInBackground(); //something goes wrong here
        }
        //three stars
    if(item.getTitle().equals("***")){
            AdapterContextMenuInfo info3 = (AdapterContextMenuInfo) item.getMenuInfo();
            ParseObject todo3 = todos.get(info3.position);

            //get the frat score
            String prevScore3 = todo3.get("FratScore").toString();

            //parse the integer value from string to int
            int intScore3 = Integer.parseInt(prevScore3);

            //increment by 3
            intScore3 = intScore3 + 3;

            //change back to a string
            String newScore3 = String.valueOf(intScore3);

            //save the parse object value here
            todo3.put("FratScore", newScore3);
            todo3.saveInBackground(); //something goes wrong here
        }
        //four stars
    if(item.getTitle().equals("****")){
            AdapterContextMenuInfo info4 = (AdapterContextMenuInfo) item.getMenuInfo();
            ParseObject todo4 = todos.get(info4.position);

            //get the frat score
            String prevScore4 = todo4.get("FratScore").toString();

            //parse the integer value from string to int
            int intScore4 = Integer.parseInt(prevScore4);

            //increment by 4
            intScore4 = intScore4 + 4;

            //change back to a string
            String newScore4 = String.valueOf(intScore4);

            //save the parse object value here
            todo4.put("FratScore", newScore4);
            todo4.saveInBackground(); //something goes wrong here
        }
        //five stars
    if(item.getTitle().equals("*****")){
            AdapterContextMenuInfo info5 = (AdapterContextMenuInfo) item.getMenuInfo();
            ParseObject todo5 = todos.get(info5.position);

            //get the frat score
            String prevScore5 = todo5.get("FratScore").toString();

            //parse the integer value from string to int
            int intScore5 = Integer.parseInt(prevScore5);

            //increment by 5
            intScore5 = intScore5 + 5;

            //change back to a string
            String newScore5 = String.valueOf(intScore5);

            //save the parse object value here
            todo5.put("FratScore", newScore5);
            todo5.saveInBackground(); //something goes wrong here
        }
    return true;    
}   

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    if(item.getItemId() == 1){
        new RemoteDataTask().execute();
        registerForContextMenu(getListView());  
    }
    return super.onOptionsItemSelected(item);
}

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    //dont really need this honestly
}

@Override
public boolean onNavigationItemSelected(int position, long itemId) {
    //Beta
    if(position == 0){
        //do nothing
    }
    //Home
    else if(position == 1){
        Intent i = new Intent(Beta_Activity.this, MainActivity.class);
        startActivity(i);
    }
    //Map
    else if(position == 2){
    }
    //ATO
    else if(position == 3){
       Intent i = new Intent(Beta_Activity.this, ATO_Activity.class);
       startActivity(i);
    }
    //Delt
    else if(position == 4){
        Intent i = new Intent(Beta_Activity.this, Delt_Activity.class);
        startActivity(i);
    }
    //Fiji
    else if(position == 5){
        Intent i = new Intent(Beta_Activity.this, Fiji_Activity.class);
        startActivity(i);
    }
    //Phi Delt
    else if(position == 6){
        Intent i = new Intent(Beta_Activity.this, PhiDelt_Activity.class);
        startActivity(i);
    }
    //Phi Psi
    else if(position == 7){
        Intent i = new Intent(Beta_Activity.this, PhiPsi_Activity.class);
        startActivity(i);
    }
    //Sig Chi
    else if(position == 8){
        Intent i = new Intent(Beta_Activity.this, SigChi_Activity.class);
        startActivity(i);
    }
    //Sig Nu
    else if(position == 9){
        Intent i = new Intent(Beta_Activity.this, SigNu_Activity.class);
        startActivity(i);
    }
    //university
    else if(position == 10){
        Intent i = new Intent(Beta_Activity.this, University.class);
        startActivity(i);
    }
    //login, create
    else if(position == 11){
        Intent i = new Intent(Beta_Activity.this, Login.class);
        startActivity(i);
    }
    return true;
}
}

listview xml：ato_listview.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" >

    <ListView
        android:id="@+id/android:list"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/android:empty"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/empty" />

</LinearLayout>

我关注的java文件的区域是“@Override public boolean onNavigationItemSelected（int position，long itemId）{“其中，基于所挑选的星星，这就是它投了多少票。它没有得到正确的项目，我想弄清楚原因。

任何和所有帮助表示赞赏！

Answer 1

包含您尝试访问的所有数据的表的名称是什么？在Parse中，您需要访问表中的特定对象。假设您的表名是“Frats”，您可以这样做：

ParseObject frat; // Place this as a global variable outside your onCreate method

// This should go in your switch statement when you receive the input as to the rating. This piece of code may not work perfectly, but should give you an idea of the structure. You want to get the actual item from the database, update the value in the column, and then save it.
ParseQuery query = new ParseQuery("Frats");
query.whereEqualTo("FratName","Beta"); // I'm just putting Beta, but it should be the frat you want (or that the user clicked)
query.findInBackground(new FindCallback() {
    public void done(List<ParseObject> fratList, ParseException e) {
        if (e != null || moodList.size() > 0) {
            frat = fratList.get(0); // I'm assuming the first instance should always be the one you work with. In fact, there should only be one instance of each
            frat.put("FratScore", Integer.parseInt(frat.getString("FratScore")) + intScore4);
            frat.saveInBackground();
        } else if (moodList.size() == 0){
             Log.w("No Frat Found!!");
        }

注意：我假设这得分为4.另外，为什么“FratScore”是一个字符串而不是一个数字？如果你总是期望它是一个数值，这是没有意义的。将其保留为字符串可以使其具有无意义的值并导致错误。

每次获取每个项目的另一种方法（正如您在query.whereEqualTo子句中所见）是从表中获取每个项目并将它们存储在数组中。但是，您的表有每个兄弟会的多个实例。要么手动删除这些，要么你有一个实例，要么如果你想要多个（每个学校一个），请添加一个具有差异值的新列（一个Sig Nu可能具有school列值作为Texas Tech而另一个是阿拉巴马州）然后通过学校检索所有的兄弟会。您只是不希望每个对象有多个实例，因为虽然名称可能相同，但它们不是同一个对象。我不能强调这一点。

它会减少对服务器的调用。如果您不理解这一点，请告诉我，我可能没有解释清楚。

Answer 2

您还可以使用getFirstInBackground来消除几行代码。以前一个答案为基础：

    query.getFirstInBackground(new GetCallback() {
        public void done(ParseObject frat, ParseException e) {
            if (e != null && frat != null) {
                frat = put("FratScore", Integer.parseInt(frat.getString("FratScore")) + intScore4);
                frat.saveInBackground();
            } else {
                Log.w("No Frat Found!!");
        }

Parse.com Android：准确地从onContextItemSelected更新ParseObjects

2 个答案: