我遇到了一些问题，我不知道如何用GTK + 2来解决。
我创建了一个函数，当我点击“Ajuda”（帮助）菜单上的“Manual”项时，它应该是一个回调函数。但是，当我编译并单击那里时，程序关闭，我不明白为什么。
开罗没有在其中一个方框上画画，事实上，它并没有在任何地方画画。
我尝试在菜单和工具栏之间创建一个水平分隔符，这似乎不可见。
对于半葡萄牙语的代码感到抱歉，我希望它不会有所作为......
#include <gtk/gtk.h>
#include <stdlib.h>
#include <math.h>
#include <cairo.h>
/*FALTA:
- Abrir o manual (dar mensagem de erro em caso de falha E compatibilidade com Windows/Mac)
*/
gboolean
help_manual(void)
{
short int x;
//x = system("xdg-open GCDmanual.pdf");
/*if (x==-1)
{
*/
return TRUE;
}
gboolean
on_expose_event (GtkWidget *widget ,
GdkEventExpose *event ,
gpointer data )
{
cairo_t *cr ;
gchar texto[128] ;
gint width, height;
static double pos1x = 100., pos1y = 80., pos2x = 600., pos2y = 100.;
static double s1x = 1., s1y = 0., s2x = 0., s2y = 0.;
static double velscale1=4, velscale2=0;
double r1=30, r2=50;
gtk_window_get_size(GTK_WINDOW(widget), &width, &height);
cr = gdk_cairo_create(widget->window);
cairo_move_to (cr, 20, 20);
cairo_select_font_face(cr, "Courier", CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_BOLD);
cairo_set_font_size (cr, 18);
sprintf (texto, "Exemplo de funcionamento de GTK+ Cairo Velocidade: %d\n",
(gint) velscale1);
cairo_show_text (cr, texto);
/* Circulo1 */
cairo_set_source_rgb (cr, 0., 0., 0.);
cairo_set_line_width (cr, 4.0);
cairo_arc (cr, pos1x, pos1y, r1, 0., 2. * M_PI);
cairo_stroke_preserve (cr);
cairo_set_source_rgb (cr, 1, 1, 1);
cairo_fill (cr);
if ((pos1x < 30.) || ((pos1x + 30.) > width))
s1x = - s1x;
if ((pos1y < 30.) || ((pos1y + 30.) > height))
s1y = - s1y;
/* Circulo2 */
cairo_set_source_rgb (cr, 0., 0., 0.);
cairo_set_line_width (cr, 4.0);
cairo_arc (cr, pos2x, pos2y, r2, 0., 2. * M_PI);
cairo_stroke_preserve (cr);
cairo_set_source_rgb (cr, 0, 1, 0);
cairo_fill (cr);
if ((pos2x < r2) || ((pos2x + r2) > width))
s2x = - s2x;
if ((pos2y < r2) || ((pos2y + r2) > height))
s2y = - s2y;
if ((pos1y-pos2y)*(pos1y-pos2y)+(pos1x-pos2x)*(pos1x-pos2x) <= (r1+r2)*(r1+r2))
{
printf("COLISAO");
//angulovelrel
printf("%lf", atan2((s2y*velscale2-s1y*velscale1),(s2x*velscale2-s1x*velscale1)));
printf("%lf", atan2((pos2y-pos1y),(pos2x-pos1x)));
}
else
{
pos1x = pos1x + s1x * velscale1;
pos1y = pos1y + s1y * velscale1;
pos2x = pos2x + s2x * velscale2;
pos2y = pos2y + s2y * velscale2;
}
cairo_stroke(cr);
cairo_destroy(cr);
return FALSE;
}
static gboolean
time_handler (GtkWidget *widget)
{
if (widget->window == NULL)
return FALSE;
gtk_widget_queue_draw(widget);
return TRUE;
}
int
main(int argc, char **argv)
{
GtkWidget *janela;
GtkWidget *vbox1, *hbox2, *vbox3_sett, *vbox3_field;
GtkWidget *vboxseparator1;
GtkWidget *menubar, *lvl1file, *lvl2file, *lvl1help, *lvl2help;
GtkWidget *file_new, * file_open, *file_sep1, *file_quit;
GtkWidget *help_manual, *help_about;
GtkWidget *toolbar;
GtkToolItem *tb_restart, *tb_pause, *tb_undo, *tb_redo, *tb_sep1;
GtkWidget *statusbar;
gtk_init(&argc, &argv);
janela=gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_window_set_title(GTK_WINDOW(janela), "Grande Colisor de Discos");
gtk_window_set_position (GTK_WINDOW (janela), GTK_WIN_POS_CENTER);
gtk_window_set_default_size (GTK_WINDOW(janela), 800, 600);
g_signal_connect_swapped (G_OBJECT(janela), "destroy",
G_CALLBACK(gtk_main_quit), NULL);
g_signal_connect (janela, "expose-event", G_CALLBACK(on_expose_event), NULL);
vbox1 = gtk_vbox_new (FALSE, 0);
gtk_box_set_homogeneous (GTK_BOX (vbox1), FALSE);
gtk_container_add (GTK_CONTAINER(janela), vbox1);
/* MENU */
menubar = gtk_menu_bar_new ();
gtk_box_pack_start (GTK_BOX (vbox1), menubar, FALSE, TRUE, 0);
lvl1file= gtk_menu_item_new_with_mnemonic ("_Ficheiro");
gtk_menu_shell_append (GTK_MENU_SHELL(menubar), lvl1file);
lvl2file = gtk_menu_new ();
gtk_menu_item_set_submenu (GTK_MENU_ITEM (lvl1file), lvl2file);
file_new = gtk_image_menu_item_new_from_stock (GTK_STOCK_NEW, NULL);
#if GTK_CHECK_VERSION(2,18,0)
gtk_image_menu_item_set_always_show_image (GTK_IMAGE_MENU_ITEM (file_new), TRUE);
#endif
file_open = gtk_image_menu_item_new_from_stock (GTK_STOCK_OPEN, NULL);
#if GTK_CHECK_VERSION(2,18,0)
gtk_image_menu_item_set_always_show_image (GTK_IMAGE_MENU_ITEM (file_open), TRUE);
#endif
file_sep1= gtk_separator_menu_item_new();
file_quit= gtk_image_menu_item_new_from_stock(GTK_STOCK_QUIT, NULL);
#if GTK_CHECK_VERSION(2,18,0)
gtk_image_menu_item_set_always_show_image (GTK_IMAGE_MENU_ITEM (file_quit), TRUE);
#endif
gtk_menu_shell_append (GTK_MENU_SHELL (lvl2file), file_new);
gtk_menu_shell_append (GTK_MENU_SHELL (lvl2file), file_open);
gtk_menu_shell_append (GTK_MENU_SHELL (lvl2file), file_sep1);
gtk_menu_shell_append (GTK_MENU_SHELL (lvl2file), file_quit);
//Ajuda
lvl1help = gtk_menu_item_new_with_mnemonic ("_Ajuda");
gtk_menu_shell_append (GTK_MENU_SHELL (menubar), lvl1help);
lvl2help = gtk_menu_new();
gtk_menu_item_set_submenu (GTK_MENU_ITEM (lvl1help), lvl2help);
help_manual=gtk_menu_item_new_with_label("Manual de ajuda");
help_about= gtk_menu_item_new_with_label("Sobre...");
gtk_menu_shell_append(GTK_MENU_SHELL(lvl2help), help_manual);
gtk_menu_shell_append(GTK_MENU_SHELL(lvl2help), help_about);
//Menu Callbacks
g_signal_connect(G_OBJECT(file_quit), "activate", G_CALLBACK(gtk_main_quit), NULL);
g_signal_connect(G_OBJECT(help_manual), "activate", G_CALLBACK(help_manual), NULL);
/* TOOLBAR */
toolbar = gtk_toolbar_new();
gtk_toolbar_set_style (GTK_TOOLBAR (toolbar), GTK_TOOLBAR_ICONS);
gtk_container_set_border_width (GTK_CONTAINER (toolbar), 0);
tb_undo = gtk_tool_button_new_from_stock (GTK_STOCK_UNDO);
gtk_widget_set_name (GTK_WIDGET (tb_undo), "undo");
gtk_toolbar_insert (GTK_TOOLBAR (toolbar), tb_undo, -1);
tb_redo = gtk_tool_button_new_from_stock (GTK_STOCK_REDO);
gtk_toolbar_insert (GTK_TOOLBAR (toolbar), tb_redo, -1);
tb_sep1 = gtk_separator_tool_item_new ();
gtk_toolbar_insert (GTK_TOOLBAR (toolbar), tb_sep1, -1);
tb_pause = gtk_tool_button_new_from_stock (GTK_STOCK_MEDIA_PAUSE);
gtk_toolbar_insert (GTK_TOOLBAR (toolbar), tb_pause, -1);
tb_restart = gtk_tool_button_new_from_stock (GTK_STOCK_REFRESH);
gtk_toolbar_insert (GTK_TOOLBAR (toolbar), tb_restart, -1);
/*tb_sep = gtk_separator_tool_item_new ();
gtk_toolbar_insert (GTK_TOOLBAR (toolbar), tb_sep, -1);*/
gtk_box_pack_start (GTK_BOX(vbox1), toolbar, FALSE, FALSE, 0);
/* HBOX2 */
vboxseparator1 = gtk_hseparator_new ();
gtk_box_pack_start (GTK_BOX (vbox1), vboxseparator1, FALSE, TRUE, 0);
gtk_widget_show (vboxseparator1);
hbox2= gtk_hbox_new (FALSE, 0);
gtk_container_add (GTK_CONTAINER(vbox1), hbox2);
/* STATUSBAR */
statusbar = gtk_statusbar_new();
gtk_box_pack_end (GTK_BOX (vbox1), statusbar, FALSE, TRUE, 0);
gtk_statusbar_push (GTK_STATUSBAR (statusbar), 1, " Isto e' uma statusbar.");
gtk_widget_show_all (janela);
gtk_main();
/* ÁREA DE TRABALHO */
vbox3_field = gtk_vbox_new (FALSE, 0);
gtk_container_add (GTK_CONTAINER (hbox2), vbox3_field);
vbox3_sett = gtk_vbox_new (FALSE, 0);
gtk_container_add (GTK_CONTAINER (hbox2), vbox3_sett);
gtk_widget_set_app_paintable (vbox3_field, TRUE);
}
答案 0 :(得分：0)
GtkMenuItem * witdget的名称是help_manual它与函数名称冲突，并且在main()函数的范围内，您传递指针GtkMenuItem而不是回调，因为你的help_manual是GtkMenuItem类型的指针而不是函数，修复是重命名回调
static void
help_manual_callback(GtkMenuItem *item, gpointer data)
{
fprintf(stderr, "ajuda!\n");
if (fork() == 0)
{
system("xdg-open GCDmanual.pdf");
_exit(0);
}
}
并连接
g_signal_connect(G_OBJECT(help_manual), "activate",
G_CALLBACK(help_manual_callback), NULL);
并且总是这样做，添加后缀或前缀来标识变量类型，这样可以更容易地跟踪类型。
这将解决崩溃，绘图问题取决于几何和其他东西，所以你应该检查它，看它是否正在绘制到正确的位置。
分隔符的可见性可能是一个主题问题，可能是您当前主题不可见的那些。
此外，您应该fork()在新流程中显示手册并保持流程运行，您可以使用线程，但我不认为它们在这种简单的情况下有用。 fork() + system()就可以了。虽然您可能希望通过指定help pdf文件的完整路径来使其更加健壮。
额外：你必须让你的代码遵循它自己的逻辑，我会为每个GUI部分创建函数，例如createToolbar()和createMenu()等。它使阅读更容易。