A continuación, un ejemplo completo del uso de GtkTreeStore. Con este ejemplo podrá insertar, modificar y eliminar filas. La línea de compilación es:

gcc -o ejemplo `pkg-config --libs --cflags gtk+-2.0` gtktreeview.c

#include (gtk/gtk.h)

GdkPixbuf *folder;

enum
{
	COLUMN_MOVE,
	COLUMN_COMMENTS,
	NUM_COLUMNS
};

/* crea el modelo tipo arbol */
GtkTreeModel * 
create_model_treeview(void)
{
	GtkTreeStore *model_store;
	
	/* creamos el modelo con 2 tipos de columnas: imagen y texto */
	model_store = gtk_tree_store_new(2, GDK_TYPE_PIXBUF, G_TYPE_STRING);
	
	return GTK_TREE_MODEL(model_store);
}

/* agrega una fila al arbol */
static void
add_row_tree (gpointer data, GtkTreeView *treeview)
{
	GtkTreeModel *model;
	GtkTreeStore *model_store;
	GtkTreeIter iter1, iter2;
	GtkTreeSelection *select;

	/* obtiene el modelo tipo arbol */
	model_store = (GtkTreeStore *) gtk_tree_view_get_model(treeview);
	
	select = gtk_tree_view_get_selection (GTK_TREE_VIEW (treeview));

	/* hay una fila seleccionada? */
	if (gtk_tree_selection_get_selected (select, &model, &iter1)) {
		gtk_tree_store_append(model_store, &iter2, &iter1);
		gtk_tree_store_set(model_store, &iter2,
				COLUMN_MOVE,folder, 
				COLUMN_COMMENTS, "fila", 
				-1);
	}else{	
		gtk_tree_store_append(model_store, &iter2, NULL);
		gtk_tree_store_set(model_store, &iter2,
				COLUMN_MOVE,folder, 
				COLUMN_COMMENTS, "Arbol", 
				-1);
	}

	g_print("add new row....\n");
}


/* modifica el contenido de una fila del arbol */
static void
mod_row_tree (gpointer data, GtkTreeView *treeview)
{
	GtkTreeModel *model;
	GtkTreeStore *model_store;
	GtkTreeSelection *select;
	GtkTreeIter iter;

	/* obtiene el modelo tipo arbol */
	model_store = (GtkTreeStore *) gtk_tree_view_get_model(treeview);
	
	select = gtk_tree_view_get_selection (GTK_TREE_VIEW (treeview));

	if (gtk_tree_selection_get_selected (select, &model, &iter)) {
		gtk_tree_store_set(model_store, &iter,
				COLUMN_MOVE,folder, 
				COLUMN_COMMENTS, "modificado", -1);
	}
	
	g_print("mod row....\n");
}

/* elimina una fila del arbol */
static void
del_row_tree (gpointer data, GtkTreeView *treeview)
{
	GtkTreeModel *model;
	GtkTreeStore *model_store;
	GtkTreeSelection *select;
	GtkTreeIter iter;

	/* obtiene el modelo tipo arbol */
	model_store = (GtkTreeStore *) gtk_tree_view_get_model(treeview);
	
	select = gtk_tree_view_get_selection (GTK_TREE_VIEW (treeview));

	/* hay una fila seleccionada? */
	if (gtk_tree_selection_get_selected (select, &model, &iter)) {
		gtk_tree_store_remove (model_store,&iter);
	}

	g_print("delete row....\n");
}

/* agrega las columnas al arbol */
static void
add_column_tree(GtkTreeView *treeview)
{
	GtkCellRenderer *renderer;
	GtkTreeViewColumn *column;

	/* crea una columna */
	column = gtk_tree_view_column_new();
	
	/* coloca el nombre a la columna */
	gtk_tree_view_column_set_title(column, "Titulo Columna");

	/* crea un render de tipo pixbuf */
	renderer = gtk_cell_renderer_pixbuf_new();
	gtk_tree_view_column_pack_start (column, renderer, FALSE);
	gtk_tree_view_column_set_attributes (column,renderer,"pixbuf",0,NULL);

	/* crea un render tipo texto */
	renderer = gtk_cell_renderer_text_new ();
	gtk_tree_view_column_pack_start (column, renderer, FALSE);
	gtk_tree_view_column_set_attributes (column,renderer,"text",1,NULL);

	/* agrega la columna al arbol */
	gtk_tree_view_append_column (treeview, column);
}

/* principal */
int 
main (int argc, char * argv[])
{
	GtkWidget *window, *scroll;
	GtkWidget *treeview;
	GtkWidget *box, *vbox;
	GtkTreeModel *model;
	GtkWidget *button_del;
	GtkWidget *button_add;
	GtkWidget *button_mod;
	
	gtk_init(&argc, &argv);

	/* genera imagen (carpeta)*/
	folder =  gdk_pixbuf_new_from_file ("folder.png", NULL);
	
	/* crear los widgets */
	window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
	/* coloca titulo a la ventana */
	gtk_window_set_title(GTK_WINDOW(window), "Ejemplo GtkTreeView");
	/* define tamaños ventana */	
	gtk_window_set_default_size(GTK_WINDOW(window), 300,400);
	/* define ancho del borde */
	gtk_container_set_border_width(GTK_CONTAINER(window), 10);

	/* crea un scroll */
	scroll = gtk_scrolled_window_new(NULL, NULL);
	
	/* crea el modelo del arbol */
	model = create_model_treeview();
	
	/* crea un nuevo widget gtktreeview */
	treeview = gtk_tree_view_new();
	
	/* agrega columnas al modelo del arbol */
	add_column_tree(GTK_TREE_VIEW(treeview));
	
	/* asocia el modelo al gtkteeview */
	gtk_tree_view_set_model(GTK_TREE_VIEW(treeview), model);

	/* agrega una fila */
	add_row_tree(NULL, GTK_TREE_VIEW(treeview));
	
	g_object_unref(G_OBJECT(model));
	
	/* empaquetador */ 
	box = gtk_hbox_new(TRUE, 10);
	vbox = gtk_vbox_new(FALSE, 5);
	gtk_widget_set_name(box, "Box");
	
	gtk_container_add(GTK_CONTAINER(scroll), treeview);
	gtk_box_pack_start(GTK_BOX(box), scroll, TRUE, TRUE, 2);

	/* crea botone */
	button_del = gtk_button_new_with_label ("Eliminar");
	button_add = gtk_button_new_with_label ("Agregar");
	button_mod = gtk_button_new_with_label ("Modificar");
	
        gtk_box_pack_start(GTK_BOX(vbox), box, TRUE, TRUE, 2);
        gtk_box_pack_start(GTK_BOX(vbox), button_del, FALSE, TRUE, 2);
        gtk_box_pack_start(GTK_BOX(vbox), button_add, FALSE, TRUE, 2);
        gtk_box_pack_start(GTK_BOX(vbox), button_mod, FALSE, TRUE, 2);

        gtk_container_add(GTK_CONTAINER(window), vbox);
	
	/* conectando las señales */
	g_signal_connect(G_OBJECT(window), "destroy", 
			gtk_main_quit, NULL);
	g_signal_connect(G_OBJECT(button_add), "clicked", 
			 G_CALLBACK(add_row_tree), treeview);
	g_signal_connect(G_OBJECT(button_del), "clicked", 
			 G_CALLBACK(del_row_tree), treeview);
	g_signal_connect(G_OBJECT(button_mod), "clicked", 
			 G_CALLBACK(mod_row_tree), treeview);
	
	gtk_widget_show_all(window);
	
	gtk_main();
	return 0;
}