C-GTK4-能够从liststore中删除行，但无法向liststore中添加行

以下是代码示例，使用gtk_list_store_insert_with_values()函数向liststore中添加行，并使用gtk_list_store_remove()函数从liststore中删除行。

#include <gtk/gtk.h>

enum {
  COLUMN_ID,
  COLUMN_NAME,
  NUM_COLUMNS
};

GtkListStore *store;

static void add_row(GtkWidget *widget, gpointer window)
{
  GtkTreeIter iter;
  gtk_list_store_insert_with_values(store, &iter, -1,
                                    COLUMN_ID, 2,
                                    COLUMN_NAME, "John Smith",
                                    -1);
  gtk_widget_show_all(GTK_WIDGET(window));
}

static void remove_row(GtkWidget *widget, gpointer list)
{
  GtkTreeSelection *selection;
  GtkTreeModel *model;
  GList *rows, *iter;
  int i = 0;
  
  selection = gtk_tree_view_get_selection(GTK_TREE_VIEW(list));
  model = gtk_tree_view_get_model(GTK_TREE_VIEW(list));
  
  rows = gtk_tree_selection_get_selected_rows(selection, &model);
  
  for (iter = rows; iter != NULL; iter = iter->next) {
    GtkTreePath *path = iter->data;
    gtk_list_store_remove(store, &iter->data);
    gtk_tree_path_free(path);
  }
  
  g_list_free(rows);
}

static gboolean delete_event(GtkWidget *widget, GdkEvent *event, gpointer data)
{
  gtk_main_quit();
  return FALSE;
}

int main(int argc, char *argv[])
{
  GtkWidget *window, *view, *vbox, *hbox, *add, *remove;
  GtkCellRenderer *renderer;
  GtkTreeViewColumn *column;

  gtk_init(&argc, &argv);

  // create the window
  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  g_signal_connect(window, "delete-event", G_CALLBACK(delete_event), NULL);
  
  // create the liststore
  store = gtk_list_store_new(NUM_COLUMNS, G_TYPE_INT, G_TYPE_STRING);
  
  // add some rows to the liststore
  gtk_list_store_insert_with_values(store, NULL, -1,
                                    COLUMN_ID, 1, 
                                    COLUMN_NAME, "Jane Doe",
                                    -1);