Das dritte GTK Grafikfenster braucht auch einen Code und hier ist er…
Quellcode für GTK Grafikfenster 3:
#include <gtk/gtk.h>
int main(int argc, char *argv[]) {
gtk_init(&argc, &argv);
GtkWidget *window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
gtk_window_set_title(GTK_WINDOW(window), "GTK Grafikfenster 03/2026");
gtk_window_set_default_size(GTK_WINDOW(window), 600, 500);
GtkCssProvider *provider = gtk_css_provider_new();
gtk_css_provider_load_from_data(provider,"* { background-color: #ff0000; }", -1, NULL);
GtkStyleContext *context = gtk_widget_get_style_context(window);
gtk_style_context_add_provider(context,
GTK_STYLE_PROVIDER(provider),
GTK_STYLE_PROVIDER_PRIORITY_USER);
gtk_widget_show_all(window);
gtk_main();
g_object_unref(provider);
return 0;
}