TutorialD1 crash due to null reference exception when Form1_Resize

[mrchipset]

Hello @RobyDX , I found a crash issue due to WindowRenderTarget target is null when Form1_Resize is invoked.

My environment:
System: Windows 10
.NET Framework: .net 4.8 and Visual Studio 2022.

After debugging the code. I found it is caused by the method calling stack:

InitializeComponent -> Form1_Resize -> Form1_Load

After adding a null check, this problem has been solved. I will create a pull request.