通过GTK C中的回调函数传递变量

#include <gtk/gtk.h>

int global_variable = 0;

void on_button_clicked(GtkWidget *button, gpointer data) {
    global_variable = 1;
}

int main(int argc, char *argv[]) {
    GtkWidget *window, *button;

    gtk_init(&argc, &argv);

    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    button = gtk_button_new_with_label("Click me");

    g_signal_connect(button, "clicked", G_CALLBACK(on_button_clicked), NULL);

    gtk_container_add(GTK_CONTAINER(window), button);
    gtk_widget_show_all(window);

    gtk_main();

    return 0;
}

#include <gtk/gtk.h>

typedef struct {
    int value;
} MyData;

void on_button_clicked(GtkWidget *button, gpointer user_data) {
    MyData *data = (MyData *)user_data;
    data->value = 1;
}

int main(int argc, char *argv[]) {
    GtkWidget *window, *button;
    MyData data;

    gtk_init(&argc, &argv);

    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    button = gtk_button_new_with_label("Click me");

    data.value = 0;

    g_signal_connect_closure(button, "clicked",
        g_cclosure_new(G_CALLBACK(on_button_clicked), &data, NULL), FALSE);

    gtk_container_add(GTK_CONTAINER(window), button);
    gtk_widget_show_all(window);

    gtk_main();

    return 0;
}