Current view of GDBG Grid

Question

I am using GDBG in a hierarchical view. 

I have an option on my form called “refresh data”, when a use click on this option I need to refresh the data in grid from database.

Everything is working fine except that my grid collapse and user has to click again to reach appropriate view.

I need to keep the current view of grid, I mean whatever level is expanded or whatever is collapse, I should keep the same. It should behave like that nothing happened except that numbers are changed.

Please help me with this.

VS

stanleyj · Answer

Hi VS,

You will have to save the expanded states before updating or giving "refresh data" and then restore them afterwards. Here is a thread that deals with this and there is a sample too. 

Best regards,
Stanley

Administrator · Answer

it would be great if there is a c# sample?

Thanks,
VS

Administrator · Answer

It is working now.

I have flickering my grid now. how can i avoid this? I am using the following code.



// save row state
ArrayList alRowState = SaveOpenRows();
				
// start grid formatting 
this.gdbgDepartmentBudget.BeginUpdate();
this.gdbgDepartmentBudget.Binder.ResetHierarchyLevels();
this.gridBudgetModel = this.gdbgDepartmentBudget.Model;
this.gridBudgetBinder = this.gdbgDepartmentBudget.Binder;
this.gdbgDepartmentBudget.DataSource = null;
this.gdbgDepartmentBudget.DataMember = null;

this.gdbgDepartmentBudget.DataMember = "budgetExpenseCategory";
this.gdbgDepartmentBudget.DataSource = dsDepartmentBudgetDetail;

gridBudgetBinder.AddRelation("Level1");

this.gdbgDepartmentBudget.EndUpdate();
this.gdbgDepartmentBudget.Refresh();


SetOpenRows(alRowState);


thanks,

Administrator · Answer

The ResetHierarchyLevels triggers a ListChanged.Reset. In this case that BeginUpdate/EndUpdate does not avoid the flicker. One other thing you can add a FreezePainting property to the grid to stop the painting in a different way that usually works. Here is a forum link with sample code on this technique. http://www.syncfusion.com/Support/Forums/message.aspx?MessageID=16065

Administrator · Answer

I am totally un-familiar with VB. do you have c# version of this sample?

Thanks,

Administrator · Answer

I tried to convert the VB code into c# but is is not doing anything.

#region "Code to Freeze System Painting for this grid"

		private const int WM_SETREDRAW  = 11;
		private int paintFrozen;

		[DllImport("User32.dll", CharSet=CharSet.Auto)]
		public static extern bool SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);

		

		private bool FreezePainting 
		{
			get {return (paintFrozen > 0); }
			set 
			{
				if (value && this.IsHandleCreated && this.Visible)
				{
					if (0 == paintFrozen)
					{
						paintFrozen = paintFrozen + 1;
						SendMessage(Handle, WM_SETREDRAW, 0, 0);
					}
					else
						paintFrozen = paintFrozen + 1;
					
				}
				
				if (!value)
				{
					if (paintFrozen == 0) 
						return;
                    
					paintFrozen = paintFrozen - 1;
					if (0 == paintFrozen)
					{
						SendMessage(Handle, WM_SETREDRAW, 1, 0);
						this.Invalidate(true);
					}

				}

			}
		}
		#endregion

Administrator · Answer

Here is the sample back with a C# project added showing how to save and restore the expand state using a new Freezepainting property added to teh grid.

http://www.syncfusion.com/Support/user/uploads/SortExpanded_10ff528c.zip