From 66729cb9cae0bca7360747a0d5c02c3f86c74785 Mon Sep 17 00:00:00 2001
From: "dedal.qq" <dedal.qq@gmail.com>
Date: Thu, 18 Mar 2021 01:50:38 +0300
Subject: [PATCH] fixing adding item into treeview if item not have parent item

---
 treeview.go | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/treeview.go b/treeview.go
index 1fb412a7c..1bb093b66 100644
--- a/treeview.go
+++ b/treeview.go
@@ -175,12 +175,16 @@ func (tv *TreeView) SetModel(model TreeModel) error {
 
 			var hInsertAfter win.HTREEITEM
 			parent := item.Parent()
-			for i := parent.ChildCount() - 1; i >= 0; i-- {
-				if parent.ChildAt(i) == item {
-					if i > 0 {
-						hInsertAfter = tv.item2Info[parent.ChildAt(i-1)].handle
-					} else {
-						hInsertAfter = win.TVI_FIRST
+			if parent == nil {
+				hInsertAfter = win.TVI_LAST
+			} else {
+				for i := parent.ChildCount() - 1; i >= 0; i-- {
+					if parent.ChildAt(i) == item {
+						if i > 0 {
+							hInsertAfter = tv.item2Info[parent.ChildAt(i-1)].handle
+						} else {
+							hInsertAfter = win.TVI_FIRST
+						}
 					}
 				}
 			}