当出现消息框时控件消失，C ++ GTK

Question

我已经用C ++编写了GUI。

#include <gtk/gtk.h>
#include <unistd.h>
#include <cstddef>
#include <iostream>
#include <string>
#include <stdio.h>
#include <stdlib.h>
int main(){
    GtkWidget *_LinuxWindow, *_Box, *_Button;
    int argC = 0;
    char** argV;
    // Setup the window and fixed grid
    gtk_init(&argC,&argV);
    _LinuxWindow = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    _Box = gtk_fixed_new();
    // Set the title
    gtk_window_set_title(GTK_WINDOW(_LinuxWindow),"Title");
    // Finish up
    gtk_widget_show(_LinuxWindow);
    g_signal_connect(G_OBJECT(_LinuxWindow),"destroy",G_CALLBACK(gtk_main_quit), NULL);
    // Add controls
    _Button = gtk_button_new_with_label("Click Me!");
    gtk_fixed_put(GTK_FIXED(_Box),_Button,20,20);
    gtk_fixed_move(GTK_FIXED(_Box),_Button,20,20);
    gtk_widget_show(_Box);
    gtk_widget_set_size_request(_Button,30,100);
    // Create a dialog
    GtkWidget *dialog;
    dialog =  gtk_message_dialog_new(GTK_WINDOW(_LinuxWindow), GTK_DIALOG_DESTROY_WITH_PARENT,GTK_MESSAGE_INFO,GTK_BUTTONS_OK_CANCEL,"OK or Cancel?",NULL,g_strerror(errno));
    gint ret = gtk_dialog_run(GTK_DIALOG(dialog));
    gtk_widget_destroy(GTK_WIDGET(dialog));
    printf("%i", ret);
    // Add the fixed grid and go the to the main window loop
    gtk_container_add(GTK_CONTAINER(_LinuxWindow),_Box);
    gtk_widget_show(_Box);
    gtk_widget_show_all(_LinuxWindow);
    gtk_main();


    return 0;
}

当我使用运行它时

g++ -o out-withoutCross without-cross.cpp -lX11 `pkg-config --cflags gtk+-3.0`pkg-config --libs gtk+-3.0`

将显示一个消息框和一个窗口。问题是打开消息框时，窗口中的控件没有出现。我认为这可能是因为消息框在与主窗口相同的线程上运行。有什么方法可以向GTK添加多线程吗？

退出主窗口后，打印到控制台的消息框的返回值也在运行。

Answer 1

问题是您的代码结构。.]]

#include <gtk/gtk.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int main() {
  GtkWidget *_LinuxWindow, *_Box, *_Button;
  int argC = 0;
  char **argV;
  // Setup the window and fixed grid
  gtk_init(&argC, &argV);
  _LinuxWindow = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  _Box = gtk_fixed_new();
  // Set the title
  gtk_window_set_title(GTK_WINDOW(_LinuxWindow), "Title");
  // Finish up
  gtk_widget_show_all(_LinuxWindow);
  g_signal_connect(G_OBJECT(_LinuxWindow), "destroy", G_CALLBACK(gtk_main_quit),
                   NULL);
  // Add controls
  _Button = gtk_button_new_with_label("Click Me!");
  gtk_fixed_put(GTK_FIXED(_Box), _Button, 20, 20);
  gtk_fixed_move(GTK_FIXED(_Box), _Button, 20, 20);
  gtk_widget_set_size_request(_Button, 30, 100);
  gtk_container_add(GTK_CONTAINER(_LinuxWindow), _Box);
  gtk_widget_show_all(_LinuxWindow);
  // Create a dialog
  GtkWidget *dialog;
  dialog = gtk_message_dialog_new(
      GTK_WINDOW(_LinuxWindow), GTK_DIALOG_DESTROY_WITH_PARENT,
      GTK_MESSAGE_INFO, GTK_BUTTONS_OK_CANCEL, "OK or Cancel?", NULL);
  gint ret = gtk_dialog_run(GTK_DIALOG(dialog));
  gtk_widget_destroy(GTK_WIDGET(dialog));
  printf("%i", ret);
  // Add the fixed grid and go the to the main window loop

  gtk_main();

  return 0;
}
gtk_dialog_run是一项阻止功能，因此它将等待，直到它从对话框中获得响应。然后继续进行]]
在您的代码中，仅在运行对话框窗口（这是一个阻塞调用）之后才将按钮添加到窗口，因此在执行之后，按钮将被添加到窗口中