Need help showing a wait cursor, image and/or message while gridview data is loading and formatting

[Patrick Baggett]

I've tried setting the wait cursor, gridview.tableElement.text and font properties before initiating data load process and then resetting to empty\default once data is loaded.  No luck using this approach and I can't seem to find much documentation on this.  Thought of approaching this by retrieving data using a separate thread - is this even possible? 

Any help would be greatly appreciated.

thanks

[erwin]

Hi Patrick,

I use the following code in many projects:

#region richard IT consulting

/*

*  $Header: /RichardConsulting.root/RichardConsulting/RichardConsulting.Utilities/UI/WaitCursor.cs 1     20.04.11 21:31 Richard $

*

*  (c)2006-2010 richard IT consulting

*          written by Erwin Richard

*          mailto:[e-mail]

*

*/

#endregion

using System;

using System.Windows.Forms;

using System.Threading;

 

namespace RichardConsulting.Utilities.UI

{

    /// <summary>

    /// Manages a Wait Cursor


    /// </summary>

    /// <remarks>

    /// <code>

    /// using(WaitCursor wait = new WaitCursor())

    /// {

    ///     // insert lengthy operation code here

    /// }

    /// </code>

    /// or even shorter

    /// <code>

    /// using(WaitCursor.Create())

    /// {

    ///     // lengthy code

    /// }

    /// </code>

    /// </remarks>

    public class WaitCursor : IDisposable

    {

 

        private static int refCount = 0;

 

        public WaitCursor()

        {

            Interlocked.Increment(ref refCount);

            Cursor.Current = Cursors.WaitCursor;

        }

 

        /// <summary>

        /// returns an IDisposable WaitCursor instance

        /// </summary>

        /// <returns></returns>

        public static IDisposable Create()

        {

            return new WaitCursor();

        }

 

        ~WaitCursor()

        {

            this.Dispose(false);

        }

 

        protected virtual void Dispose(bool disposing)

        {

            if (Interlocked.Decrement(ref refCount) == 0)

            {

                Cursor.Current = Cursors.Default;

            }

        }

 

        #region IDisposable Members

 

        public void Dispose()

        {

            this.Dispose(true);

            GC.SuppressFinalize(this);

        }

        #endregion

    }

}

An advantage is that you don't need a reference to a control or form.
Nested lengthy passages are handled quite well too - if you use other cursors than standard and wait/hourglass, you have to extend the functionality a bit to save/restore the previous cursor.

Regards
Erwin

[Stefan]

Hello guys,

@Erwin - thank you for sharing your code with the community. I have updated your Telerik points for your time and effort.

@Patrick - you can use the Erwin code for a cursor. Alternatively, here is a small sample demonstrating loading data into a DataTable in a background thread and then assigning it to RadGridView:

public partial class Form1 : Form
  {

      BackgroundWorker worker;
      DataTable table;
      public Form1()
      {
          InitializeComponent();
      }

      private void radButton1_Click(object sender, EventArgs e)
      {
          radGridView1.TableElement.Font = new System.Drawing.Font("Arial", 20);
          radGridView1.Cursor = Cursors.WaitCursor;
          radGridView1.TableElement.Text = "Loading data";

          table = new DataTable();

          worker = new BackgroundWorker();
          worker.DoWork += new DoWorkEventHandler(worker_DoWork);
          worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
          worker.RunWorkerAsync();
      }

      void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
      {
          radGridView1.DataSource = table;

          radGridView1.TableElement.ResetValue(LightVisualElement.FontProperty, Telerik.WinControls.ValueResetFlags.Local);
          radGridView1.Cursor = Cursors.Arrow;
          radGridView1.TableElement.ResetValue(LightVisualElement.TextProperty, Telerik.WinControls.ValueResetFlags.Local);
      }

      void worker_DoWork(object sender, DoWorkEventArgs e)
      {
          table.Columns.Add("col");
          for (int i = 0; i < 400000; i++)
          {
              table.Rows.Add(i);
          }
      }
  }

One more approach to notify the user of a time taking process is RadWaitingBar. Sample is available here: http://www.telerik.com/help/winforms/track-and-status-controls-waitingbar-using-radwaitingbar-with-a-background-worker.html.

I hope that you find this information useful.

Regards,
Stefan
the Telerik team