如何从Azure移动服务检索数据并绑定到Android ListView

Question

I am currently trying to retrieve the data I have inserted into Azure Mobile Services into a ListView in my Android application. I tried to follow the tutorial Microsoft provided but my items are not showing up in the ListView. The example they provided had a checkbox in it, which I do not need. I just wanna display my Entry Name and the Date + Time I have inserted into the database table into the ListView. This is my list view layout:

entry_listview.xml

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

    <TextView
        android:id="@+id/tvEntryName"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:text="Entry name"/>

    <TextView
        android:id="@+id/tvEntryDateTime"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:text="date/time"/>
</LinearLayout>

and then this is my adapter Entry Item Adapter

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;

import java.security.KeyStore;

public class EntryItemAdapter extends ArrayAdapter<EntryItem> {

    Context mContext;

    int mLayoutResourceId;

    public EntryItemAdapter(Context context, int layoutResourceId) {
        super(context, layoutResourceId);

        mContext = context;
        mLayoutResourceId = layoutResourceId;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;

        final EntryItem currentItem = getItem(position);

        if (row == null) {
            LayoutInflater inflater = ((Activity) mContext).getLayoutInflater();
            row = inflater.inflate(mLayoutResourceId, parent, false);
        }

        row.setTag(currentItem);


        return row;
    }
}

last but not least, the activity where I wanna display the ListView AllEntriesActivity.java

import android.content.Intent;
import android.content.res.TypedArray;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;


import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutionException;

import java.net.MalformedURLException;

import com.microsoft.windowsazure.mobileservices.MobileServiceClient;
import com.microsoft.windowsazure.mobileservices.table.MobileServiceTable;
import com.microsoft.windowsazure.mobileservices.table.sync.MobileServiceSyncContext;
import com.microsoft.windowsazure.mobileservices.table.sync.localstore.ColumnDataType;
import com.microsoft.windowsazure.mobileservices.table.sync.localstore.MobileServiceLocalStoreException;
import com.microsoft.windowsazure.mobileservices.table.sync.localstore.SQLiteLocalStore;
import com.microsoft.windowsazure.mobileservices.table.sync.synchandler.SimpleSyncHandler;

import static com.microsoft.windowsazure.mobileservices.table.query.QueryOperations.val;

import android.os.AsyncTask;


public class AllEntriesActivity extends BaseActivity {
    private MobileServiceClient mClient;
    private MobileServiceTable<EntryItem> mEntryTable;
    private EntryItemAdapter mAdapter;

    private String[] navMenuTitles;
    private TypedArray navMenuIcons;

    Button btnAddEntry;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_all_entries);
        try {
            // Create the Mobile Service Client instance, using the provided

            // Mobile Service URL and key
            mClient = new MobileServiceClient(
                    "https://skerydiary.azure-mobile.net/",
                    "farvbebCTbuqVueYGNugUivXktrljJ72",
                    this);


            mEntryTable = mClient.getTable(EntryItem.class);

            //initLocalStore().get();

            // Create an adapter to bind the items with the view
            mAdapter = new EntryItemAdapter(this, R.layout.entry_listview);
            ListView listViewEntryItems = (ListView) findViewById(R.id.listViewEntries);
            listViewEntryItems.setAdapter(mAdapter);

            // Load the items from the Mobile Service
            refreshItemsFromTable();

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

        navMenuTitles = getResources().getStringArray(R.array.nav_drawer_items); // load
        // titles
        // from
        // strings.xml

        navMenuIcons = getResources()
                .obtainTypedArray(R.array.nav_drawer_icons);// load icons from
        // strings.xml

        set(navMenuTitles, navMenuIcons);


        btnAddEntry = (Button) findViewById(R.id.btnAddNewEntry);
        btnAddEntry.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent addEntryIntent = new Intent(AllEntriesActivity.this, AddNewEntry.class);
                addEntryIntent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
                overridePendingTransition(0, 0);
                startActivity(addEntryIntent);

            }
        });
    }

//    public void loadItem(final EntryItem item) {
//        if (mClient == null) {
//            return;
//        }
//
//        // Set the item as completed and update it in the table
//        //item.setComplete(true);
//
//        AsyncTask<Void, Void, Void> task = new AsyncTask<Void, Void, Void>(){
//            @Override
//            protected Void doInBackground(Void... params) {
//                try {
//
//                    //checkItemInTable(item);
//                    runOnUiThread(new Runnable() {
////                        @Override
////                        public void run() {
////                            if (item.isComplete()) {
////                                mAdapter.remove(item);
////                            }
////                        }
//                    });
//                } catch (final Exception e) {
//                    createAndShowDialogFromTask(e, "Error");
//                }
//
//                return null;
//            }
//        };
//
//        runAsyncTask(task);
//    }

    private void refreshItemsFromTable() {

        // Get the items that weren't marked as completed and add them in the
        // adapter

        AsyncTask<Void, Void, Void> task = new AsyncTask<Void, Void, Void>(){
            @Override
            protected Void doInBackground(Void... params) {

                try {
                    final List<EntryItem> results = refreshItemsFromMobileServiceTable();

                    //Offline Sync
                    //final List<ToDoItem> results = refreshItemsFromMobileServiceTableSyncTable();

                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            mAdapter.clear();

                            for (EntryItem item : results) {
                                mAdapter.add(item);
                            }
                        }
                    });
                } catch (final Exception e){
                    createAndShowDialogFromTask(e, "Error");
                }

                return null;
            }
        };

        runAsyncTask(task);
    }

    private List<EntryItem> refreshItemsFromMobileServiceTable() throws ExecutionException, InterruptedException {
        return mEntryTable.where().field("active").
                eq(val(true)).execute().get();
    }

    private AsyncTask<Void, Void, Void> initLocalStore() throws MobileServiceLocalStoreException, ExecutionException, InterruptedException {

        AsyncTask<Void, Void, Void> task = new AsyncTask<Void, Void, Void>() {
            @Override
            protected Void doInBackground(Void... params) {
                try {

                    MobileServiceSyncContext syncContext = mClient.getSyncContext();

                    if (syncContext.isInitialized())
                        return null;

                    SQLiteLocalStore localStore = new SQLiteLocalStore(mClient.getContext(), "OfflineStore", null, 1);

                    Map<String, ColumnDataType> tableDefinition = new HashMap<String, ColumnDataType>();
                    tableDefinition.put("id", ColumnDataType.String);
                    tableDefinition.put("date", ColumnDataType.String);
                    tableDefinition.put("time", ColumnDataType.String);
                    tableDefinition.put("newentry", ColumnDataType.String);
                    tableDefinition.put("description", ColumnDataType.String);
                    tableDefinition.put("location", ColumnDataType.String);
                    tableDefinition.put("image", ColumnDataType.String);

                    localStore.defineTable("EntryItem", tableDefinition);

                    SimpleSyncHandler handler = new SimpleSyncHandler();

                    syncContext.initialize(localStore, handler).get();

                } catch (final Exception e) {
                    createAndShowDialogFromTask(e, "Error");
                }

                return null;
            }
        };

        return runAsyncTask(task);
    }

    private void createAndShowDialogFromTask(final Exception exception, String title) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                createAndShowDialog(exception, "Error");
            }
        });
    }

    private void createAndShowDialog(Exception exception, String title) {
        Throwable ex = exception;
        if (exception.getCause() != null) {
            ex = exception.getCause();
        }
        createAndShowDialog(ex.getMessage(), title);
    }

    private void createAndShowDialog(final String message, final String title) {
        final android.app.AlertDialog.Builder builder = new android.app.AlertDialog.Builder(this);

        builder.setMessage(message);
        builder.setTitle(title);
        builder.create().show();
    }

    private AsyncTask<Void, Void, Void> runAsyncTask(AsyncTask<Void, Void, Void> task) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            return task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
        } else {
            return task.execute();
        }
    }

}

I have no idea what's wrong, no error is thrown and my activity doesn't show anything in the list view.

Answer 1

Verify that the mobile service is returning data. Set a breakpoint on the following line:

final List results = refreshItemsFromMobileServiceTable()

Then, view the results of the results List.

->If results is empty, you either have no data or there is a problem with your mobile service or there is a problem with the call to your mobile service.

->If results contains the expected data, you have a problem with the code displaying this data to your form.