想要将"GdkPixbuf"转换为"GtkSelectionData"对象

我想将我的pixbuf转换为" gtkselectiondata"，那么我如何在C 中转换它？以下是我的示例代码。

clipboard   =   gtk_clipboard_get_for_display (gdk_display_get_default (),
                                                     GDK_SELECTION_CLIPBOARD);
                GdkPixbuf *pixbuf;
                pixbuf = gtk_clipboard_wait_for_image ( clipboard );
                if ( pixbuf != NULL )
                {
                    int width, height;
                    width  = gdk_pixbuf_get_width (pixbuf);
                    height = gdk_pixbuf_get_height (pixbuf);
                    //printf("width : %d", width);
                    GtkSelectionData *selectionData;
                gtk_selection_data_set_pixbuf(selectionData,pixbuf);
                g_object_unref (pixbuf);
                 }
Error: cannot convert ‘GdkPixbuf* {aka _GdkPixbuf*}’ to ‘GtkSelectionData* {aka _GtkSelectionData*}’ in initialization

谢谢，吉米特