Vba Application.Onkey Press F3 not working during Cursor flashing inside Cell

[vbexceltuto]

I create some code for test Press F3 on VBA Excel, the function is Application.OnKey this method excel not working during write on the Cell and Cursor Flashing inside Cell, but work fine after pressing Enter

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
   Application.OnKey "{F3}", "MyMacro"
End Sub

I want this method work during cursor flashing

 

[Fluff]

You cannot run macros whilst in Edit Mode, so unfortunately you cannot do that.