I wrote a code in GTK3 and works fine: <http://gtk.10911.n7.nabble.com/file/n90800/myApp-Entry.png> And I get: invalid cast from 'GtkButton' to 'GtkEntry' And I can't figure out where the problem is.This happens After the User type something and hits the Button. Here is the Code: #include <gtk/gtk.h> static void btn_clicked(GtkWidget *widget, gpointer data) { g_print("%s\n", gtk_entry_get_text(GTK_ENTRY(data))); gtk_editable_select_region(GTK_EDITABLE(data), 0,-1); gtk_editable_copy_clipboard(GTK_EDITABLE(data)); } int main(int argc, char *argv[]) { GtkWidget *window, *grid; GtkWidget *label, *label_fn; GtkWidget *fn_entry; GtkWidget *button; //---------- CSS ------------- GtkCssProvider *provider; GdkDisplay *display; GdkScreen *screen; //--------------------------- gtk_init(&argc, &argv); window = gtk_window_new(GTK_WINDOW_TOPLEVEL); gtk_window_set_title(GTK_WINDOW(window), "MyApp"); gtk_window_set_default_size(GTK_WINDOW(window), 370, 155); gtk_window_set_resizable (GTK_WINDOW(window), TRUE); gtk_container_set_border_width(GTK_CONTAINER(window), 5); g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL); /* Create a Grid */ grid = gtk_grid_new(); gtk_container_set_border_width(GTK_CONTAINER (grid), 15); gtk_widget_set_name(grid, "myGrid"); gtk_grid_set_column_spacing(GTK_GRID(grid), 5); gtk_grid_set_row_spacing(GTK_GRID(grid), 5); gtk_container_add(GTK_CONTAINER(window), grid); /* Create first Label */ label = gtk_label_new("Please enter your Information:"); gtk_widget_set_margin_top(label, 25); gtk_widget_set_margin_start(label, 85); /* Create second Label */ label_fn = gtk_label_new("First Name: "); gtk_widget_set_margin_start(label_fn, 10); /* Create an Entry: */ fn_entry = gtk_entry_new(); /* Create a Button */ button = gtk_button_new_with_mnemonic("_Write text"); g_signal_connect(button, "clicked", G_CALLBACK(btn_clicked), fn_entry); g_signal_connect(fn_entry, "activate", G_CALLBACK(btn_clicked), fn_entry); /* Putting all together */ gtk_grid_attach(GTK_GRID(grid), label, 0, 0, 2, 1); gtk_grid_attach(GTK_GRID(grid), label_fn, 0, 1, 1, 1); gtk_grid_attach(GTK_GRID(grid), fn_entry, 1, 1, 1, 1); gtk_grid_attach(GTK_GRID(grid), button, 1, 2, 1, 1); // ---------------------------------------------------- CSS ----------------------------------------------------------- provider = gtk_css_provider_new (); display = gdk_display_get_default (); screen = gdk_display_get_default_screen (display); gtk_style_context_add_provider_for_screen (screen, GTK_STYLE_PROVIDER (provider), GTK_STYLE_PROVIDER_PRIORITY_APPLICATION); const gchar *myCssFile = "mystyle.css"; GError *error = 0; gtk_css_provider_load_from_file(provider, g_file_new_for_path(myCssFile), &error); g_object_unref (provider); // -------------------------------------------------------------------------------------------------------------------- gtk_widget_show_all(window); gtk_main(); return 0; } CSS File: GtkWindow { background-color: magenta; color: black; border-width: 3px; border-color: blue; } #myGrid { background-color: red; border-style: solid; border-color: black; border-width: 3px; border-radius: 15px; border-color: grey; } And I compile it with the following: gcc -Wall -Wextra -g myApp.c -o myApp `pkg-config --cflags --libs gtk+-3.0 ` After I type something and I hit the Button (Write text) I get the following errors (warnings): (myApp:10151): GLib-GObject-WARNING **: invalid cast from 'GtkButton' to 'GtkEntry' (myApp:10151): Gtk-CRITICAL **: gtk_entry_get_text: assertion 'GTK_IS_ENTRY (entry)' failed (null) (myApp:10151): GLib-GObject-WARNING **: invalid cast from 'GtkButton' to 'GtkEditable' (myApp:10151): Gtk-CRITICAL **: gtk_editable_select_region: assertion 'GTK_IS_EDITABLE (editable)' failed (myApp:10151): GLib-GObject-WARNING **: invalid cast from 'GtkButton' to 'GtkEditable' (myApp:10151): Gtk-CRITICAL **: gtk_editable_copy_clipboard: assertion 'GTK_IS_EDITABLE (editable)' failed Does Anyone know how to fix this? -- View this message in context: http://gtk.10911.n7.nabble.com/invalid-cast-from-GtkButton-to-GtkEntry-tp90800.html Sent from the Gtk+ - General mailing list archive at Nabble.com. _______________________________________________ gtk-list mailing list gtk-list@xxxxxxxxx https://mail.gnome.org/mailman/listinfo/gtk-list