GTK+设置控件背景图片

void update_widget_bg(GtkWidget *widget, const gchar *img_file){        GtkStyle *style;      GdkPixbuf *pixbuf;        GdkPixmap *pixmap;      gint width, height;      pixbuf = gdk_pixbuf_new_from_file(img_file, NULL);     width = gdk_pixbuf_get_width(pixbuf);    height = gdk_pixbuf_get_height(pixbuf);     pixmap = gdk_pixmap_new(NULL, width, height, 24);    gdk_pixbuf_render_pixmap_and_mask(pixbuf, &pixmap, NULL, 0);style = gtk_style_copy(GTK_WIDGET (widget)->style);      if (style->bg_pixmap[GTK_STATE_NORMAL])             g_object_unref(style->bg_pixmap[GTK_STATE_NORMAL]);      style->bg_pixmap[GTK_STATE_NORMAL] = g_object_ref(pixmap);     style->bg_pixmap[GTK_STATE_ACTIVE] = g_object_ref(pixmap);style->bg_pixmap[GTK_STATE_PRELIGHT] = g_object_ref(pixmap);style->bg_pixmap[GTK_STATE_SELECTED] = g_object_ref(pixmap);style->bg_pixmap[GTK_STATE_INSENSITIVE] = g_object_ref(pixmap);gtk_widget_set_style(GTK_WIDGET (widget), style);g_object_unref(style);}