＜Linux＞ Ubuntu 第一个UI应用程序

Ubuntu的桌面是gnome,基于gtk开发的,gtk是C语言开发的,总结来说Ubuntu的桌面是C写的.

本次例程是在Ubuntu 19.10上做的,其它版本类似.

1,安装环境

# 安装编译环境
$ sudo apt-get install build-essential

# 安装gtk,截止今天,最新版是3.99,19.10自带3.0
$ sudo apt-get install libgtk-3-dev

# 安装示例代码
$ sudo apt-get install gtk-3-examples

2,创建&编译项目

# 直接复制示例工程
cp /usr/share/doc/gtk-3-examples/examples/hello-world.c .

# 编译
gcc `pkg-config --cflags gtk+-3.0` -o hello_world hello-world.c `pkg-config --libs gtk+-3.0`

gtk示例hello_world.c代码如下:

#include 

static void
print_hello (GtkWidget *widget,
             gpointer   data)
{
  g_print ("Hello World\n");
}

static void
activate (GtkApplication *app,
          gpointer        user_data)
{
  GtkWidget *window;
  GtkWidget *button;
  GtkWidget *button_box;

  window = gtk_application_window_new (app);
  gtk_window_set_title (GTK_WINDOW (window), "Window");
  gtk_window_set_default_size (GTK_WINDOW (window), 200, 200);

  button_box = gtk_button_box_new (GTK_ORIENTATION_HORIZONTAL);
  gtk_container_add (GTK_CONTAINER (window), button_box);

  button = gtk_button_new_with_label ("Hello World");
  g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
  g_signal_connect_swapped (button, "clicked", G_CALLBACK (gtk_widget_destroy), window);
  gtk_container_add (GTK_CONTAINER (button_box), button);

  gtk_widget_show_all (window);
}

int
main (int    argc,
      char **argv)
{
  GtkApplication *app;
  int status;

  app = gtk_application_new ("org.gtk.example", G_APPLICATION_FLAGS_NONE);
  g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
  status = g_application_run (G_APPLICATION (app), argc, argv);
  g_object_unref (app);

  return status;
}

如果感觉代码比较多,这里还有个简版的:

#include 
 
int main(int argc,char **argv){
    GtkWidget *window;
    gtk_init(&argc,&argv);
    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(window),"hello world");
    gtk_window_set_default_size(GTK_WINDOW(window),400,300);
    gtk_window_set_position(GTK_WINDOW(window),GTK_WIN_POS_CENTER);
    gtk_widget_show(window);
    g_signal_connect_swapped(G_OBJECT(window),"destroy",
        G_CALLBACK(gtk_main_quit),NULL);
    gtk_main();
    return 0;
}

3,查看效果

# 运行程序
./hello_world