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How to combine two or more columns with Android SimpleCursorAdapter

SimpleCursorAdapter adapter = new SimpleCursorAdapter( this, R.layout.mytaskslayout, cursor, new String[] {"Aircraft","Discrepancy","ARR_FLT"}, new int[] {R.id.ac, R.id.discrepancy, R.id.arrinfo} );

Is it possible to combine two or more columns and display them in a single R.id.XXX file? If so, how?

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You can create a SimpleCursorAdapter.ViewBinder for this. See this answer for an example.

Basically your ViewBinder will be called for each view. Therefore, when you get to the idea that you want to have both columns, just get both column values, combine them and set the value in the view yourself.

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Finally found a solution. I had the same question as someone new to Android and Xamarin for Android. To be clear - I use Xamarin Studio and Xamarin for Android, written in C #.

Although it seems that a SimpleCursorAdapter can hold multiple fields, when binding to something like SimpleListItem, only one field is used.

I first tried this:

  string[] fromColumns = new string[]{ "checkListName","checkListDesc" }; int[] toControlIDs = new int[] {Android.Resource.Id.Text1, Android.Resource.id.Text1}; try{ listView.Adapter = new SimpleCursorAdapter(this,Android.Resource.Layout.SimpleListItem1 , c, fromColumns, toControlIDs, 0); } catch(SQLiteException e){ Console.WriteLine ("whoops, " + e.Message.ToString ()); }

But all I ever got was the last field on the cursor line.

I found out that CUSTOM LISTVIEW is needed . Below are the code files for the four files:

  • MainActivity.cs
  • myList.xml
  • Main.axml
  • PreFloat.cs (this is part of the database)

I included all this in order to maximize the use of a fully working model, which is as close as possible to real life.

Here, MainActivity.cs, which sets the content view, uses the cursor to retrieve data from the SQLite database and defines

 using System; using Android.App; using Android.Content; using Android.Database; using Android.Database.Sqlite; using Android.Runtime; using Android.Views; using Android.Widget; using Android.OS; namespace Darjeeling { [Activity (Label = "Darjeeling", MainLauncher = true, Icon = "@drawable/icon")] public class MainActivity : Activity { ListView listView; Darjeeling.PreFloatDatabase pdb; ICursor c; protected override void OnCreate (Bundle bundle) { base.OnCreate (bundle); // Set our view from the "main" layout resource SetContentView (Resource.Layout.Main); listView = FindViewById<ListView> (Resource.Id.listView1); pdb = new PreFloatDatabase (this); // Assign the cursor to a query c = pdb.ReadableDatabase.RawQuery ("select * from checkLists", null); StartManagingCursor (c); // A ListView needs an adapter -- so we'll assign our instantiated listView adapter to our customized adapter called HomeScreenCursorAdapter. listView.Adapter = (IListAdapter)new HomeScreenCursorAdapter (this,c); } // End onCreate method // This handles the cursor when the user is done with the activity protected override void OnDestroy() { StopManagingCursor(c); c.Close (); base.OnDestroy(); } // Here the magic -- public class HomeScreenCursorAdapter : CursorAdapter { Activity context; public HomeScreenCursorAdapter(Activity context, ICursor c) : base (context, c) { this.context = context; } // This overridden BindView method is going to let me assign TextView controls that I've set up in an XML file, to specific fields in the cursor. public override void BindView(View view, Context context, ICursor cursor) { var txtCheckListName = view.FindViewById<TextView> (Resource.Id.txtCheckListName); //(Android.Resource.Id.Text1); var txtCheckListDesc = view.FindViewById<TextView> (Resource.Id.txtCheckListDesc); //(Android.Resource.Id.Text2); // For testing purposes, I first assigned static values to txtCheckListName and txtCheckListDesc, for instance, txtCheckListName.Text = "Hello"; and txtCheckListDesc.Text = "World"; txtCheckListName.Text = cursor.GetString (3); txtCheckListDesc.Text = cursor.GetString (4); } // This overridden View inflates each row (I think). This could inflate a built-in ListView control like SimpleListItem, OR, in this case, it references a custom written XML file called myList. public override View NewView(Context context, ICursor cursor, ViewGroup parent) { return this.context.LayoutInflater.Inflate (Resource.Layout.myList, parent, false); } } }

}

Here is the Main.axml file:

 <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@+id/linearLayout1" android:minWidth="25px" android:minHeight="25px"> <ListView android:minWidth="25px" android:minHeight="25px" android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/listView1" /> </LinearLayout>

And finally, the myList.xml file, which is essentially the definition of a ListView string:

 <?xml version="1.0" encoding="utf-8"?> <!---<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="200dp" android:layout_height="match_parent" android:background="#FF0000FF"> --> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@+id/linearLayout1" android:minWidth="25px" android:minHeight="25px"> <TextView android:id="@+id/txtCheckListName" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:text="" /> <TextView android:id="@+id/txtCheckListDesc" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="0" android:text="" /> </LinearLayout> <!---</FrameLayout>-->

And here is the database file:

 using System; using Android.Database.Sqlite; using Android.Content; namespace Darjeeling { class PreFloatDatabase : SQLiteOpenHelper { public static readonly string create_checkLists_table = "create table if not exists checkLists([_id] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL UNIQUE, checkListID INTEGER, checkListType INTEGER, checkListName TEXT, checkListDesc TEXT);"; public static readonly string DatabaseName = "prefloat.db"; public static readonly int DatabaseVersion = 1; public PreFloatDatabase (Context context) : base (context, DatabaseName, null, DatabaseVersion){ } public override void OnCreate(SQLiteDatabase db){ // fire the statement that creates the checkLists table try{ db.ExecSQL (create_checkLists_table); // Now pre-fill the checkLists table db.ExecSQL ("insert into checkLists (checkListID, checkListType, checkListName, checkListDesc) values (0, 0, 'Widgeon','Widgeon Daysailer');"); db.ExecSQL ("insert into checkLists (checkListID, checkListType, checkListName, checkListDesc) values (1, 1, 'Widgeon','Widgeon Daysailer');"); db.ExecSQL ("insert into checkLists (checkListID, checkListType, checkListName, checkListDesc) values (2, 0, 'Bowrider', 'Mo Motor, Mo Fun');"); db.ExecSQL ("insert into checkLists (checkListID, checkListType, checkListName, checkListDesc) values (3, 1, 'Bowrider', 'Mo Motor, Mo Fun');"); db.ExecSQL ("insert into checkLists (checkListID, checkListType, checkListName, checkListDesc) values (4, 0, 'HobieCat','Hang yer ass out fun');"); db.ExecSQL ("insert into checkLists (checkListID, checkListType, checkListName, checkListDesc) values (5, 1, 'HobieCat','Hang yer ass out fun');"); } catch(SQLiteException e){ Console.WriteLine ("Problem with the database " + e.Message.ToString ()); } } public override void OnUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){ throw new NotImplementedException (); } } // matches with class PreFloatDatabase } // matches with namespace Darjeeling

Questions: SHOULD a SimpleListItem control have more than one field or, at most, a checkbox control and a label? Should grid management be used instead?

Alternatives: Instead of doing all these frauds, would it be easier to simply combine the necessary values ​​using SQL? Moreover, coordinating the positioning of two text controls can be too complicated.

Full disclosure: This code is an amalgam of code that I read in other posts and forums, and is configured according to my own requirements.

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