ValidateChildren will descend a control's hierarchy and examine each control to see if it supports validation. If the control can be selected by the user and its CausesValidation property is true, ValidateChildren will cause the Validating event to occur. If any of the controls cancel the Validating event, this method will return false; otherwise, it will return true.
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.
The following code example turns off implicit validation for a form and all of its contained controls, and instead manually performs validation of all of the form's children when a mouse button is clicked.