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Design Time

To start using RadValidationProvider just drag it from the toolbox and drop it onto the form.

Smart Tag

Select RadValidationProvider and click the small arrow at the top right position in order to open the Smart Tag. Open the FilterDescriptor Collection Editor by clicking the Edit Validation Rules option in the Smart tag.

WinForms RadValidationProvider FilterDescriptor Collection Editor

The different Validation Rules that RadValidationProvider offers can be added at design time without the necessity of writing any code once the FilterDescriptor Collection Editor is opened.


RadValidationRule allows you to define validation logic for a single control considering a validation operator and a fixed value.

We will add a rule that validates the value in a RadSpinEditor and ensures that it is less than 100:

  1. Add a RadValidationRule and select the RadSpinEditor control that you want to validate from the Controls collection:

    WinForms RadValidationProvider Add RadValidationRule

  2. Set the Operator to IsLessThan, PropertyName to Value, ToolTipText to "Value should be less than 100!":

    WinForms RadValidationProvider Setup Rule

  3. Set the Value to 100 and then select int from the types drop down:

    WinForms RadValidationProvider Value

    WinForms RadValidation-Provider validation-provider-design-time 003

    The data type of the Value can be specified after entering a value first and then selecting the type from the drop down. Thus, the correct expression will be serialized.

When you enter a value and try to exit RadSpinEditor, the validation rule will be evaluated and an error indication will be shown if the validation fails:

WinForms RadValidationProvider Validate RadSpinEditor


RadValidationRuleWithTargetControl allows you to define validation logic of a control against a second control, e.g. if you have two RadSpinEditor controls for selecting minimum/maximum price and you need to ensure that minimum price is less than maximum price.

  1. Add a RadValidationRuleWithTargetControl and select the "minimum price" RadSpinEditor from the Controls collection:

    WinForms RadValidationProvider Add RadValidationRuleWithTargetControl

    WinForms RadValidation-Provider Select RadSpinEditor

  2. Set the Operator to IsLessThan, PropertyName to Value, ToolTipText to "Minimum price should be less than Maximum price!":

    WinForms RadValidationProvider Setup Rule

  3. Select the "maximum price" RadSpinEditor as TargetControl and set the TargetControlPropertyName to Value:

    WinForms RadValidationProvider Select TargetControl

Please ensure that the initial values in both RadSpinEditor controls meet the validation. Otherwise, you may remain blocked when you focus the "minimum price" RadSpinEditor for the first time, e.g. if both controls have initial value = 0. No matter what value you enter in the "minimum price" RadSpinEditor, you want to be able to validate it and exit the control.

WinForms RadValidationProvider Validation Failed

In a similar way you can add a rule to validate that the "maximum price" RadSpinEditor's value is greater than the value of the first one. Thus, when you focus the second RadSpinEditor and try to exit it, it will ensure that a valid value (greater than minimum) is added.


RadCompositeValidationRule allows defining more complex validation logic by adding multiple simpler validation rules.

Considering the previous example with minimum and maximum price, we want to validate "price" RadSpinEditor (radSpinEditor3) which value should be within the [minimum,maximum] range.

  1. For this purpose, it is necessary to add a RadCompositeValidationRule which contains two RadValidationRuleWithTargetControls:

    WinForms RadValidationProvider Add RadCompositeValidationRule

    WinForms RadValidationProvider Add RadValidationRuleWithTargetControls

  2. The first RadValidationRuleWithTargetControl should validate that "price" RadSpinEditor is greater than "minimum price" RadSpinEditor:

    WinForms RadValidationProvider GreaterThan Price

    WinForms RadValidationProvider RadValidationRuleWithTargetControl with RadSpinEditor

  3. The second RadValidationRuleWithTargetControl should validate that "price" RadSpinEditor is less than "maximum price" RadSpinEditor:

    WinForms RadValidationProvider LessThan

    WinForms RadValidationProvider Second RadValidationRuleWithTargetControl with RadSpinEditor

    None of the associated controls (e.g. radSpinEditor3) of a composite rule should be added as a target in any of the nested rules! Please be careful when defining composite rules in order to get the proper validation logic. Usually, it is even possible to simplify the validation logic and define separate RadValidationRuleWithTargetControls outside a composite rule.

  4. Once you have added the nested rules, return back to the RadCompositeValidationRule and specify the LogicalOperator and ToolTipText:

    WinForms RadValidationProvider LogicalOperator

When you start the application and enter a price that doesn't meet the validations rules, the specified error message for the composite rule will be shown:

WinForms RadValidationProvider Composite Rule Validation

See Also

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