VB.NET Obj Ref not set in datetime - asp.net

Question

I've seen similar questions through extensive 'google-ing' but none have been able to sort this issue out, the error I'm getting from VS13 is below:
An exception of type 'System.NullReferenceException' occurred in
my.dll but was not handled in user code. Additional information:
Object reference not set to an instance of an object.
Simply put I want a default date value to populate within the calendar textbox so the user doesn't have to choose a date, or if they forget etc it'll put the system time in.
I've tried converting toString etc and I get the same error.
Any help would be gratefully received.
Thanks in advance.
Code behind:
Public Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
Dim SrtDateTxt As New TextBox
SrtDateTxt = ListView1.FindControl("StartDateTextBox")
SrtDateTxt.Text = DateTime.Now
End If
End Sub
And the aspx that the above code behind relates to:
<asp:TextBox ID="StartDateTextBox" runat="server" Text='<%# Bind("StartDate") %>' Width="150px"/>
<act:CalendarExtender ID="CalendarExtender1" runat="server" TargetControlID="StartDateTextBox" Format="yyyy-MM-dd"></act:CalendarExtender>

Answer 1

First i want to suggest to change Option Strict to "On" in your project's settings. That won't you prevent from compiler errors but from nasty runtime errors. Fixing the compiler errors will teach you much about the types in the .NET framework.
Then for example this will not compile anymore:
SrtDateTxt.Text = DateTime.Now
You need to assign a string instead of a Date:
SrtDateTxt.Text = DateTime.Now.ToString() ' or ToShortDateString()
Next, this will not prevent you from a NullRefernceException:
Dim SrtDateTxt As New TextBox
If you assign another value to this variable one line afterwards:
SrtDateTxt = ListView1.FindControl("StartDateTextBox")
So i assume that SrtDateTxt is Nothing because there is no control with that ID in the ListView but in one of it's ListViewItems(which are different NamingContainers).
Therefore you get the exception at the next line when you try to access a property
SrtDateTxt.Text = DateTime.Now ' at .Text
A ListView is meant to be used for multiple items. So you need to use the correct ListViewItem.
For Each item As ListViewItem In ListView1.Items
Dim StartDateTextBox = DirectCast(item.FindControl("StartDateTextBox"), TextBox)
' ... '
Next
This loops all items, i don't know if that is what you want to do.