使用 GtkFileChooserButton 和 GtkFileChooserDialog 的区别

Question

我想让用户选择两个目录，然后在单击按钮后检索它们的 URI，这样我就可以将它们传递给另一个函数。现在我尝试做一些事情：

directory1 = gtk_file_chooser_button_new ("Choose directory 1",GTK_FILE_CHOOSER_ACTION_SELECT_FOLDER);

directory2 相同。然后把它们放在 struct

里面

struct directories {
    GtkWidget *first;
    GtkWidget *second;
};

struct directories directory;
    directory.first = directory1;
    directory.second = directory2;

点击按钮后将其传递给函数，该函数目前除了尝试检索 URI 并打印它们外什么都不做。

g_signal_connect(button, "clicked", G_CALLBACK(print_test), &directory);

print_test (struct directories *dirc)
{
    g_print("%s\n", gtk_file_chooser_get_uri(GTK_FILE_CHOOSER(dirc->first)));
    g_print("%s\n", gtk_file_chooser_get_uri(GTK_FILE_CHOOSER(dirc->second)));
}

我也尝试用 GTK_FILE_CHOOSER_BUTTON 替换 GTK_FILE_CHOOSER 但结果是一样的：我的程序已编译，我选择了一些目录并在激活按钮后崩溃并打印了一个

(null)

和以下调试信息

GLib-GObject-WARNING **: 02:52:03.786: invalid uninstantiatable type 'gchararray' in cast to 'GtkFileChooserButton'
Gtk-CRITICAL **: 02:52:03.786: gtk_file_chooser_get_uri: assertion 'GTK_IS_FILE_CHOOSER (chooser)' failed

我认为 gtk_file_chooser_button 是一个很好的解决方案，因为它似乎比手动建立对话框更容易使用，但现在我开始质疑我是否被允许那样使用它或者我的程序失败了将指针传递给 print_test 的错误方法的错误。不幸的是，我找到的所有例子都集中在使用对话框上，所以我没有找到一个很好的例子来学习如何使用 gtk_file_chooser_button.

编辑：根据请求，我展示了我的代码示例。我只删除了与此问题无关的其他类型的按钮，并执行了第一条评论中描述的更改，因此与上述问题相比，您可以观察到两行中的细微差别。

#include <stdio.h>
#include <gtk/gtk.h>

struct directories {
    GtkWidget *first;
    GtkWidget *second;
};

static void
print_test (GtkWidget *somewidget, struct directories *dirc)
{
    g_print("%s\n", gtk_file_chooser_get_uri(GTK_FILE_CHOOSER(dirc->first)));
    g_print("%s\n", gtk_file_chooser_get_uri(GTK_FILE_CHOOSER(dirc->second)));
}

static void
set_expand (GtkWidget *widget)
{
    gtk_widget_set_hexpand(widget, 1);
    gtk_widget_set_vexpand(widget, 1);
}

static void
activate (GtkApplication* app,
          gpointer        user_data)
{
    GtkWidget *window;
    GtkWidget *grid;
    GtkWidget *frame;
    GtkWidget *settings;
    GtkWidget *directory1;
    GtkWidget *directory2;
    GtkWidget *button;

    //Prepare the window
    window = gtk_application_window_new (app);
    gtk_window_set_title (GTK_WINDOW (window), "Sagger");
    gtk_window_set_default_size (GTK_WINDOW (window), 400, 200);
    gtk_window_set_position(GTK_WINDOW(window),GTK_WIN_POS_CENTER);

    //Prepare the grid
    grid = gtk_grid_new();
    //gtk_grid_set_column_homogeneous(grid, 1);
    //gtk_widget_set_halign (grid, GTK_ALIGN_FILL);
    //gtk_widget_set_valign (grid, GTK_ALIGN_FILL);
    set_expand(grid);
    gtk_container_add(GTK_CONTAINER(window), grid);

    //Prepare directory chooser
    settings = gtk_box_new(GTK_ORIENTATION_VERTICAL, 0);
    frame = gtk_frame_new("Choose directories");
    set_expand(settings);
    gtk_container_add(GTK_CONTAINER(frame), settings);
    directory1 = gtk_file_chooser_button_new ("Source directory",GTK_FILE_CHOOSER_ACTION_SELECT_FOLDER);
    set_expand(directory1);
    gtk_container_add(GTK_CONTAINER(settings), directory1);
    directory2 = gtk_file_chooser_button_new ("Target directory",GTK_FILE_CHOOSER_ACTION_SELECT_FOLDER);
    set_expand(directory2);
    gtk_container_add(GTK_CONTAINER(settings), directory2);
    gtk_grid_attach(grid, frame, 0, 0, 2, 1);

    //Prepare the run button
    settings = gtk_button_box_new(GTK_ORIENTATION_HORIZONTAL);
    gtk_button_box_set_layout(GTK_BUTTON_BOX(settings), GTK_BUTTONBOX_EXPAND);
    set_expand(settings);
    gtk_grid_attach(grid, settings, 0, 2, 2, 1);
    button = gtk_button_new_with_label("RUN");

    //Try to pass the chosen directories
    struct directories directory;
    directory.first = directory1;
    directory.second = directory2;
    g_signal_connect(G_OBJECT(button), "clicked", G_CALLBACK(print_test), (gpointer) &directory);

    gtk_container_add(GTK_CONTAINER(settings), button);

    gtk_widget_show_all (window);
}

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

    app = gtk_application_new ("pl.etua.sagger", 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;
}

Answer 1

directory 是 activate() 函数的局部函数，并且如评论中所述，当它超出范围时将被销毁。稍后，当单击按钮调用 print_test() 函数时，它将尝试访问此内存，从而导致分段错误。

两个简单的解决方法：

使directory全局化：

struct directories {
    GtkWidget *first;
    GtkWidget *second;
};
struct directories directory;

或在 activate() 中将其设为静态：

static struct directories directory;

使用 GtkFileChooserButton 和 GtkFileChooserDialog 的区别

The difference between using GtkFileChooserButton and GtkFileChooserDialog

c

gtk

gtk3