toggle-button有个函数

void gtk_toggle_button_set_inconsistent (GtkToggleButton *toggle_button, gboolean setting);
If the user has selected a range of elements (such as some text or spreadsheet cells) that are affected by a toggle button, and the current values in that range are inconsistent, you may want to display the toggle in an "in between" state. This function turns on "in between" display. Normally you would turn off the inconsistent state again if the user toggles the toggle button. This has to be done manually, gtk_toggle_button_set_inconsistent() only affects visual appearance, it doesn't affect the semantics of the button.

toggle_button : a GtkToggleButton
setting : TRUE if state is inconsistent


各位大神，有谁知道，帮我讲解一下吧！

这个貌似表示的是一种第三状态，即介于选中和非选中的一种状态。
如GtkCheckButton中的勾在这个状态下会显示成灰色。