ContainerControl.ValidateChildren Method (ValidationConstraints)
Causes all of the child controls within a control that support validation to validate their data.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
[<BrowsableAttribute(false)>] abstract ValidateChildren : validationConstraints:ValidationConstraints -> bool [<BrowsableAttribute(false)>] override ValidateChildren : validationConstraints:ValidationConstraints -> bool
You may use several ValidationConstraints parameters at once by combining them with a bitwise OR operator. Combining parameters with a bitwise OR operator will result in a logical AND operation. For example, calling ValidateChildren(ValidationConstraints.ImmediateChildren | ValidationConstraints.Enabled) will only raise the Validating event on controls that are both immediate children of the container AND are enabled.
Regardless of which parameters you specify for this method, a control must have its CausesValidation property set to true in order for its Validating event to occur. You should also set the AutoValidate property of the control or of the control's container to false if you want validation to happen only when you call ValidateChildren, and not when the user shifts focus from the control.
If a control is bound to a data source, and the Validating event occurs, it will cause the control to push its current data back to the data source.
You cannot achieve the opposite effect of a ValidationConstraints parameter by applying a bitwise negation operator. For example, if you supply the negative value of the Visible field to ValidateChildren, it will not validate all children that are not visible on the container. Supplying any negative parameter to ValidateChildren will have no effect on the container or its children.