When overridden in a derived class, returns the expression string that is formed by the expression editor sheet property values.
The custom expression string for the current property values.
A custom expression editor sheet contains design-time settings for multiple expression properties, which are combined to form an expression string. Control property values can be set using expression strings; the expression strings are evaluated at run time by an expression builder.
The ExpressionEditorSheet.GetExpression method returns an expression string that is built from the current expression properties. The visual designer allows you to set the expression sheet properties, and then calls the ExpressionEditorSheet.GetExpression method to get the expression string and set the control property value.