Resetting a field''s value if validation fails

[Nick Dalgiannakis]

Hi,

I''m using a DataBound grid and it seems that, by default, if there is a validation error (like typing a non-numeric string in a numeric cell), a message box with the relevant exception shows up. What''s the easiest way of overriding this behavior to simply reset the cell''s value to the last valid value and move on? Which event handlers do I need to implement?

I''ve tried binder.resetField(currentCell.colIndex) in the grid''s ValiateFailed event but that didn''t work.

Thanks for your help.

Rgds,
Nick

[Administrator]

Hi Nick, To handle, the validation error. You can handle it in the CurrentCellValidating Event. Here is the Code snippet.

		private void gridDataBoundGrid1_CurrentCellValidating(object sender, System.ComponentModel.CancelEventArgs e)
		{
			GridCurrentCell cc  =  this.gridDataBoundGrid1.CurrentCell;
			int i = Convert.ToInt32(this.gridDataBoundGrid1[cc.RowIndex,cc.ColIndex].CellValue);				
			if(cc.ColIndex == 2)
			{
				string newValue = cc.Renderer.ControlText;
				try
				{
					double d = double.Parse(newValue);
				}
				catch
				{					
					e.Cancel = true;	
					cc.Renderer.ControlText = i.ToString();
				}
			}
		}

Refer to sample for details Let me know if you further assistance, Regards, Madhan.

Forum_18Jan_39792.zip

[Nick Dalgiannakis]

Thanks for your reply Madhan. This works well if you put your validation code on the grid level. I would like, however, to let each cell type (including custom types) deal with its own validation (so leave it to each model/renderer). However, I''m not sure which method I need to implement/override to get this done.

Is there any documentation that details what the chain of events is (and on what objects) when a user goes to a cell, types a value and then moves out of that cell, specifically for DataBound grids? And how do the default handlers behave (i.e. what methods do they call)?

Thanks again for your help.

Rgds,
Nick

[stanleyj]

Hi Nick, If you browse through the CellTypes samples that are shipped, that will display an event log which, will show the order of the currentcell events that are raised and the values that are in the cell as the events occur. You will be able to see mouse events as well. You can also learn through the knowledgeBase articles, here is one article explaining the different validation events. Best regards, Stanley