Cannot copy pallet text box

TextBox, Combobox, and DataGridView were placed on Palette to create a pallet for information entry.
In Combobox, you can copy strings with Ctrl-C and Ctrl-V by selecting strings, but in TextBox and DataGridView cells, you can manipulate the entities in the drawing.
I would appreciate it if you could tell me how to enable string copying just like Combobox.
I look forward to your kind cooperation.