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View this topic on docs.devexpress.com (Learn more)

Cell Validation

The GridControl allows you to validate new cell values. The image below shows a GridControl with an invalid cell value:


A complete sample project is available in the DevExpress Code Examples database at http://www.devexpress.com/example=E1592.

Follow the steps below to validate a cell's value:

Expanded Step 1. Handle a Validating Event

The GridControl provides the following events to validate cell values manually:


The GridControl does not raise these events by default when changing cell values in code. Set the DataViewBase.AllowLeaveInvalidEditor property to true to enable raising events.

The code sample below shows how to validate the UnitPrice column's cell values:

Expanded Step 2. Validate a New Value

Use the following GridCellValidationEventArgs's properties to get cell values:

You can verify values according to validation rules after obtaining them. If a cell's value fails validation, set the ValidationEventArgs.IsValid property to false. In this case, an end-user cannot move focus to another cell until the cell's value is valid.

In the following code sample, the product's price cannot be reduced by over 30% if the product is discontinued:

Expanded Step 3. Indicate Errors

The GridControl displays an error icon within the cell if an edited cell's value is invalid:

Use the following GridCellValidationEventArgs's properties to customize the error indication:

The code sample below demonstrates how to show an error tooltip depending on the entered value:

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