From 2638f02cd6d7d73cf067fa3c3b6ed8bdf5e23aea Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Tue, 18 Jul 2017 09:55:10 +0100
Subject: [PATCH 1/2] fix null reference when focusing textbox in attached to
 visual tree,

but before ontemplate applied.
---
 src/Avalonia.Controls/TextBox.cs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/TextBox.cs b/src/Avalonia.Controls/TextBox.cs
index d2e8085d8c..6fc79e5d2c 100644
--- a/src/Avalonia.Controls/TextBox.cs
+++ b/src/Avalonia.Controls/TextBox.cs
@@ -236,6 +236,11 @@ namespace Avalonia.Controls
         {
             _presenter = e.NameScope.Get<TextPresenter>("PART_TextPresenter");
             _presenter.Cursor = new Cursor(StandardCursorType.Ibeam);
+
+            if(IsFocused)
+            {
+                _presenter.ShowCaret();
+            }
         }
 
         protected override void OnGotFocus(GotFocusEventArgs e)
@@ -254,7 +259,7 @@ namespace Avalonia.Controls
             }
             else
             {
-                _presenter.ShowCaret();
+                _presenter?.ShowCaret();
             }
         }
 

From c37dd6cda923f65da21aa4a9b6a0a35c30bd431a Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Tue, 18 Jul 2017 10:02:15 +0100
Subject: [PATCH 2/2] null check on hide caret.

---
 src/Avalonia.Controls/TextBox.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/TextBox.cs b/src/Avalonia.Controls/TextBox.cs
index 6fc79e5d2c..92ab12f82e 100644
--- a/src/Avalonia.Controls/TextBox.cs
+++ b/src/Avalonia.Controls/TextBox.cs
@@ -268,7 +268,7 @@ namespace Avalonia.Controls
             base.OnLostFocus(e);
             SelectionStart = 0;
             SelectionEnd = 0;
-            _presenter.HideCaret();
+            _presenter?.HideCaret();
         }
 
         protected override void OnTextInput(TextInputEventArgs e)