Gets the number that specifies the height of a component as a percentage of its parent's size.
Allowed values are 0-100. The default value is NaN. Setting the height or explicitHeight properties resets this property to NaN.
This property returns a numeric value only if the property was previously set; it does not reflect the exact size of the component in percent.
This property is always set to NaN for the UITextField control.
'Declaration
Protected Read Property percentHeight As Double