Retrieving Multiple rows from SQLite in Xamarin iOS - sqlite

Question

I'm doing an app with Xamarin iOS.
I put a UITableView on XCode, so that when I click on a button, it retrieves from the database and slot it in. I'm able to put it onto a row, but couldn't figure it out how to have multiple rows of data in it. This is my partial code from which I'm able to display a row of data.
cmd.CommandType = CommandType.Text;
dr = cmd.ExecuteReader();
while (dr.Read())
{
var table = new UITableView(this.retrieveData.Frame);
string[] tableItems = new String[] {dr["admin_num"] + ", " + dr["name"]};
table.Source = new TableSource(tableItems);
Add (table);
}

Answer 1

You are creating a completely new TableView for each row in your data. Instead, you should loop through your data and create a data structure (List, array, etc) containing ALL of the data you want to display, and then pass that data to your TableView/Source.
cmd.CommandType = CommandType.Text;
dr = cmd.ExecuteReader();
// you will need a class mydata with Num and Name properties
List<mydata> data = new List<mydata>();
while (dr.Read())
{
data.Add(new mydata { Num = dr["admin_num"], Name = dr["name"] });
}
dr.Close();
var table = new UITableView(this.retrieveData.Frame);
table.Source = new TableSource(data);
Add (table);

Answer 2

What you need to do is this:
public List<DemoClass> getDemoClassList()
{
List<DemoClass> lstDemoClass;
DemoClass objDemoClass;
try
{
String strCommandText;
strCommandText = "SELECT * FROM DemoClass ";
command = new SqliteCommand(strCommandText, connection);
lstDemoClass = new List<DemoClass>();
using (var reader = command.ExecuteReader())
{
while (reader.Read())
{
objDemoClass = new Homes(false);
objDemoClass.ID = Convert.ToInt32(reader[0]);
objDemoClass.Name = Convert.ToString(reader[1]);
lstDemoClass.Add(objDemoClass);
}
}
return lstDemoClass;
}
catch (Exception ex)
{
throw ex;
}
finally
{
command.Dispose();
command = null;
lstDemoClass = null;
objDemoClass = null;
}
}
public void BindList()
{
List<DemoClass> lstDemoClass = new List<DemoClass>();
DemoClass hm = new DemoClass();
lstDemoClass = (List<DemoClass>)hm.getDemoClassList();
TableViewDataSource tdatasource = new TableViewDataSource(this, lstDemoClass);
table.Hidden = false;
table.DataSource = tdatasource;
table.Delegate = new TableViewDelegate(this, table, lstDemoClass);
table.ReloadData();
}
The getDemoClassList() will give the retrieved list from SQLite table, and later you can bind the list to the table datasource.
UPDATE:
As per your request I have updated my comment with the code for datasource and its delegate classes.
Now in this same class you need to add the following subclasses:
#region TableDelegate
public class TableViewDelegate : UITableViewDelegate
{
private DemoPageViewController _Controller;
private List<DemoClass> lst;
public TableViewDelegate(DemoPageViewController controller ,UITableView tableView, List<DemoClass> tblList)
{
try
{
this._Controller = controller;
this.lst = tblList;
}
catch(Exception ex)
{
}
}
public override void RowSelected (UITableView tableView, NSIndexPath indexPath)
{
try
{
//This loads the activity spinner till the selection code is completed
_Controller._loadPop = new LoadingOverlay (new System.Drawing.RectangleF(0,0,_Controller.View.Frame.Width,_Controller.View.Frame.Height),"Loading...");
_Controller.View.Add ( _Controller._loadPop );
// spin up a new thread to do some long running work using StartNew
Task.Factory.StartNew (
// tasks allow you to use the lambda syntax to pass work
() => {
InvokeOnMainThread(delegate{
DemoClass f = lst[indexPath.Row];
//Add your code here, usually some navigation or showing a popup
});
}).ContinueWith(t => InvokeOnMainThread(() => {
//Hide the activity spinner
_Controller._loadPop.Hide();
}));
}
catch(Exception ex)
{
}
finally
{
}
}
}
#endregion
#region TableDataSource
private class TableViewDataSource : UITableViewDataSource
{
static NSString kCellIdentifier = new NSString("MyIdentifier");
private List<DemoClass> lst;
private DemoPageViewController controller;
public TableViewDataSource (DemoPageViewController controller ,List<DemoClass> tblLst)
{
this.controller = controller;
this.lst = tblLst;
}
public override int NumberOfSections (UITableView tableView)
{
return 1;
}
public override int RowsInSection (UITableView tableView, int section)
{
return lst.Count;
}
// Override to support conditional editing of the table view.
public override bool CanEditRow (UITableView tableView, MonoTouch.Foundation.NSIndexPath indexPath)
{
// Return false if you do not want the specified item to be editable.
return false;
}
public override UITableViewCell GetCell (UITableView tableView, NSIndexPath indexPath)
{
try
{
UITableViewCell cell = tableView.DequeueReusableCell (kCellIdentifier);
if (cell == null)
{
cell = new UITableViewCell (UITableViewCellStyle.Subtitle, kCellIdentifier);
cell.Tag = Environment.TickCount;
}
DemoClass objDemo = lst[indexPath.Row];
cell.Accessory = UITableViewCellAccessory.DisclosureIndicator;
cell.ImageView.Image = UIImage.FromFile("Images/CameraImg.png");
cell.DetailTextLabel.Text = "Show some detail: " + objDemo.DemoDescription.ToString();
cell.TextLabel.Text = "Some Title: " + objDemo.DemoTitle.ToString();
return cell;
}
catch(Exception ex)
{
return null;
}
finally
{
}
}
}
#endregion
Hope it helps.