[ Version ( since = "3.20" ) ]
public void set_cancel_label (string? cancel_label)
Sets the custom label text for the cancel button.
If characters in label are preceded by an underscore, they are underlined. If you need a literal underscore character in a
label, use “__” (two underscores). The first underlined character represents a keyboard accelerator called a mnemonic. Pressing Alt
and that key activates the button.
| this |
a |
| cancel_label |
custom label or null for the default |