title: add list to gtk_tree_view in C
body: <p>folks, </p>
  
  <p>im gonna tryin to make a little function which has something todo with the Gtk_tree_view that i've made,
  the error response such as like this :</p>
  
  <pre><code>(main:8026): Gtk-CRITICAL **: IA__gtk_tree_view_get_model: assertion `GTK_IS_TREE_VIEW (tree_view)' failed
  
  (main:8026): Gtk-CRITICAL **: IA__gtk_list_store_append: assertion `GTK_IS_LIST_STORE (list_store)' failed
  
  (main:8026): Gtk-CRITICAL **: IA__gtk_list_store_set_valist: assertion `GTK_IS_LIST_STORE (list_store)' failed
  ^C
  </code></pre>
  
  <p>and the source, here you go :</p>
  
  <pre><code> void addlist(bahan *unit, const gchar *str)
      {
          GtkListStore *store;
          GtkTreeIter iter; // penyambung store_append and store_set
  
          store = GTK_LIST_STORE(gtk_tree_view_get_model(GTK_TREE_VIEW(unit-&gt;treeview_aktifitas)));
  
          gtk_list_store_append(store, &amp;iter); // need unary &amp;, coz iter aint define like a pointer
          gtk_list_store_set(store, &amp;iter, 1, str, -1);
      }
  </code></pre>
  
  <p>as you've figured , the structure of 'unit' was supposed like this :</p>
  
  <pre><code>  typedef struct
      {
          GtkWidget *window;
          GtkWidget *notebook;
          GtkWidget *start;
          GtkWidget *verbose;
          GtkWidget *settings;
          GtkWidget *about;
          GtkWidget *statusbar;
          GtkWidget *treeview_aktifitas;
          guint statusbar_id;
      } bahan;
  </code></pre>
  
  <p>and connected by this :</p>
  
  <pre><code>  unit-&gt;treeview_aktifitas = GTK_WIDGET(gtk_builder_get_object(main,"treeview1"));
  </code></pre>
  
  <p>in the real case, im using 'glade 3', and have two columns on glade file, how to set on gtk_list_store_set ?</p>
  
  <p>very appreciate any further help :)</p>