在 GTK3+ C 中创建菜单

Question

所以我正在尝试使用 C 在 GTK3+ 中创建一个简单的菜单。我正在尝试重新创建在以下位置找到的菜单:

https://developer.gnome.org/gtk-tutorial/stable/x743.html

所以我复制了代码，并一直试图隔离我需要的部分，并将所说的部分转换为 3+。我对这个代码段不太走运。首先，不推荐使用 gtk_option_menu，取而代之的是 gtk_combo_box。我试图找到相关的教程，但没有任何结果。

老实说，我什至不知道如何使用 GTK 创建菜单背后的理论，所以我很难进行转换。我在这里几乎是瞎飞。

我的代码如下:

#include "/usr/include/gtk-3.0/gtk/gtk.h"

static void print_stuff( GtkWidget *item, gpointer data) {

    printf("Hello World!\n");
    return;
}

static GtkWidget *make_menu_item(gchar *name, GCallback callback, gpointer data ){

    GtkWidget *item;  
    item = gtk_menu_item_new_with_label (name);
    g_signal_connect (item, "activate", callback, (gpointer) data);
    gtk_widget_show (item);
    return item;
}


static void create_range_controls( void ){

    GtkWidget *window;
    GtkWidget *box1, *box2, *box3;
    GtkWidget *button;
    GtkWidget *scrollbar;
    GtkWidget *separator;
    GtkWidget *opt, *menu, *item;
    GtkWidget *label;
    GtkWidget *scale;
    GObject *adj1, *adj2;

    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), "range controls");

    box1 = gtk_box_new(GTK_ORIENTATION_VERTICAL, 0);
    gtk_container_add(GTK_CONTAINER (window), box1);
    gtk_widget_show(box1);

    opt = gtk_option_menu_new ();
    menu = gtk_menu_new ();
    item = make_menu_item ("Top", G_CALLBACK (print_stuff), NULL);
    gtk_menu_shell_append (GTK_MENU_SHELL (menu), item);

    item = make_menu_item ("Bottom",  G_CALLBACK (print_stuff), NULL);
    gtk_menu_shell_append (GTK_MENU_SHELL (menu), item);

    item = make_menu_item ("Left",  G_CALLBACK (print_stuff), NULL);
    gtk_menu_shell_append (GTK_MENU_SHELL (menu), item);

    item = make_menu_item ("Right",  G_CALLBACK (print_stuff), NULL);
    gtk_menu_shell_append (GTK_MENU_SHELL (menu), item);

    gtk_option_menu_set_menu(GTK_OPTION_MENU(opt), menu);
    gtk_box_pack_start(GTK_BOX (box1), opt, TRUE, TRUE, 0);
    gtk_widget_show(opt);

    gtk_widget_show (window);

}

int main( int argc, char *argv[] ){

    gtk_init (&argc, &argv);

    create_range_controls ();

    gtk_main ();

    return 0;
}

谁能说明我做错了什么，为什么？是否有 GTK3+ 的教程，比如我上面链接的 GTK2+ 教程？

谢谢!

Answer 1

很难手动完成所有操作。您可以将 glade 用于快速开发接口(interface)。但这里有一个关于如何在 gtk+-3.x 系列中使用菜单和 gtk_combo_box 的小例子:

// cc menu-gtk3.c `pkg-config --cflags --libs gtk+-3.0` -o menu-gtk3

#include <gtk/gtk.h>

void cb_combo_change (GtkComboBox *combo, gpointer user_data) {
    gint index = gtk_combo_box_get_active (combo);
    if (index) { // we need some string to be displayed
        GtkTreeModel *model;
        GtkTreeIter iter;
        gchar *buf;
        model = gtk_combo_box_get_model (combo);
        gtk_tree_model_iter_nth_child (model, &iter, NULL, index);
        gtk_tree_model_get (model, &iter, 0, &buf, -1);
        g_print ("%s\n", buf);
        g_free (buf);
    }
}

void show_message_cb (GtkMenuItem *item, gpointer user_data) {
    g_print ("Hello world\n");
}

int main (int argc, char *argv[]) {
    GtkWidget *toplevel;
    GtkWidget *center_vbox;
    GtkWidget *menuBar;
    GtkWidget *menuItem1;
    GtkWidget *submenu1;
    GtkWidget *item_message;
    GtkWidget *item_quit;
    GtkWidget *combobox;
    GtkListStore *combo_ls;
    GtkCellRenderer *renderer;
    GtkTreeIter iter;
    gtk_init (&argc, &argv);
    /* create toplevel window */
    toplevel = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    /* create the box here */
    center_vbox = gtk_box_new(GTK_ORIENTATION_VERTICAL, 0);
    /* create menubar */
    menuBar =gtk_menu_bar_new ();
    /* create 1st menu item */
    menuItem1 = gtk_menu_item_new_with_mnemonic ("_Application");
    /* add the submenu for the 1st menu item */
    submenu1 = gtk_menu_new ();
    /* add the message item */
    item_message = gtk_menu_item_new_with_label ("Message");
    /* add the quit item menu for the submenu */
    item_quit = gtk_menu_item_new_with_label ("Quit");
    /* create the list model for the combo */
    combo_ls = gtk_list_store_new (1, G_TYPE_STRING);
    /* add some strings */
    gtk_list_store_append (combo_ls, &iter);
    gtk_list_store_set (combo_ls, &iter, 0, "Choose one", -1);
    gtk_list_store_append (combo_ls, &iter);
    gtk_list_store_set (combo_ls, &iter, 0, "String1", -1);
    gtk_list_store_append (combo_ls, &iter);
    gtk_list_store_set (combo_ls, &iter, 0, "String2", -1);
    /* add a combobox with the model
     * you could use combo_box_text for faster text append */
    combobox = gtk_combo_box_new_with_model (GTK_TREE_MODEL (combo_ls));
    /* destroy here the model, because you increase its reference
     * by attach it to the combo */
    g_object_unref (combo_ls);
    /* now prepare the combo */
    renderer = gtk_cell_renderer_text_new ();
    gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (combobox), renderer, TRUE);
    gtk_cell_layout_set_attributes (GTK_CELL_LAYOUT (combobox), renderer, "text", 0, NULL);
    /* set index to 0 */
    gtk_combo_box_set_active (GTK_COMBO_BOX (combobox), 0);
    /* packing */
    gtk_menu_shell_append (GTK_MENU_SHELL (submenu1), item_message);
    gtk_menu_shell_append (GTK_MENU_SHELL (submenu1), item_quit);
    gtk_menu_item_set_submenu (GTK_MENU_ITEM (menuItem1), submenu1);
    gtk_menu_shell_append (GTK_MENU_SHELL (menuBar), menuItem1);
    gtk_box_pack_start (GTK_BOX (center_vbox), menuBar, TRUE, TRUE, 0);
    gtk_box_pack_start (GTK_BOX (center_vbox), combobox, FALSE, FALSE, 0);
    gtk_container_add (GTK_CONTAINER (toplevel), center_vbox);
    /* signal handlers */
    g_signal_connect (toplevel, "destroy", G_CALLBACK (gtk_main_quit), NULL);
    g_signal_connect (combobox, "changed", G_CALLBACK (cb_combo_change), NULL);
    g_signal_connect_swapped (item_quit, "activate", G_CALLBACK (gtk_widget_destroy), toplevel);
    g_signal_connect (item_message, "activate", G_CALLBACK (show_message_cb), NULL);
    /* let them loose */
    gtk_widget_show_all (toplevel);
    gtk_main ();
    return 0;
}