I'm using a NumericTextBox for editing a cell. I have MinValue and MaxValue set to 0 and 100. When I enter a value outside the range, an error indicator appears around the cell, and what looks like a tooltip over the row header. But when I hover over that tooltip, there is no message. I can't figure out how to set the content for that tooltip.

 I've read the validation topics in the docs, but to be honest, find them to be confusing.

Hi james, 

To return a custom validation message, you’ll need to return
        new ValidationResult( false, "My custom message." );
in the validation function in the code-behind.

For more information, you may check the example here:
http://doc.xceedsoft.com/products/XceedWpfDataGrid/Xceed.Wpf.DataGrid.v4.3~Xceed.Wpf.DataGrid.ValidationRules.CellValidationRule.html

 If this doesn't help you, can you please provide us of a snippet or a little demo project so we can have a better grasp of what you are trying to do? 
Thanks

Sebastien,

I'm not using a validation rule, I set the MinValue and MaxValue properties on my NumericTextBox. If I enter a value outside that range, then the cell shows the red border, and the red icon appears over the row header. I realize now that there is a a tooltip message, but it only appears when I hover over the cell. That marker on the row header doesn't show the tooltip. Maybe that is good, if a row has multiple errors, which tooltip would it show? I don't know, I haven't worked with the grid for very long.

In any event, the tooltip over the cell is not very helpful. It says "The value "" could not be converted". Of course what I would like it to say is something like "The value entered is less that the MinValue property" or something. I just went ahead and did a cell validation rule, so I can supply my own custom message (which would be better, anyway, than the one in the previous sentence). I removed the MinValue and MaxValue settings on the NumericTextBox and delegate all validation to this rule.

Thanks.

Jim

Hi james,

Can you send me a little demo project so I can have a better look of what you are trying to do please?

 Thanks 

I've solved the current issue. It's obvious that the error icon on the row header is not intended to show a tooltip, and by using a custom rule I'm supplying the message I want for the tooltip over the cell.

http://xceed.com/CS/forums/thread/32562.aspx