gtk + -3.0 transparent implementation

gtk + -3.0 transparent implementation, from google search to some of the transparent window approach , but they are the gtk + -2.0

those in gtk + -3.0 API are no longer used , gtk + -3.0 window transparent how, I've tried a variety of methods , but they can not be achieved ,

I mainly use gtkmm composite manager through open , transparent window can be set set_opacity found that I and all of the contents of the window transparent , and do not drag the normal draw ,

also tried using CSS , and found that the window is a black background , and did not achieve transparency,


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though do not know gtk + -3.0, but the landlord can try cario, see if you can achieve the effect of the main floor
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GTK +3.0 unclear , not used . But is this a transparent GTK2.0

void gtk_window_set_opacity (GtkWindow *window, gdouble opacity);

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cairro actually tried it , may be the cairro unfamiliar, did not appear transparent effect ,
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this useless , no effect ah , has been resolved ,
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