textview glade-2

[Debian User <wide288 yahoo com cn>]

Hi,everyone
   about textview widget ,I think know When i use glade-2 create a
   window , textview, button, etc widget.(in interface.c file) How to string(gchar *str1) write to textview. 
(in callback.c) .
   How to textview's string write to string (gchar *str2), "printf("%s\n",str2);" . 
   How to clear textview widget's text .
   i do it .no good.:
   ==============================
   filename : interface.c :
   g_signal_connect_swapped ((gpointer) button1, "clicked",
                               G_CALLBACK (on_button1_clicked),
                               GTK_OBJECT (textview1));

filename: callback.c :
void
on_button1_clicked                     (GtkButton       *button,
                                        gpointer         user_data)
{       //clean textview's text
        GtkTextBuffer *textbuffer =NULL;
        g_assert(GTK_IS_TEXT_VIEW(user_data));
        textbuffer =gtk_text_view_get_buffer(GTK_TEXT_VIEW (user_data));
        gtk_text_buffer_delete_selection(textbuffer,TRUE, TRUE);
 }

                                               wide288
                                                2004-7-3