How can I check to see if a variable is null in VB?

Question

I want to check if a variable is null. Apparently...

If var1 Is Not Null Then

is no longer supported.

Null is no longer available in .NET. The replacement is System.DBNull but it doesn't seem to function the same way.

Answer 1

The IsNot operator in VB.net is your best bet:

if myVar IsNot Nothing then
...
end if

It is the most portable, IsNull relies on Microsoft.VisualBasic.dll and this is just plain illogical:

if Not myVar Is Nothing
...
end if

Spock would be most displeased. Live long and prosper!

Answer 2

i've got confidence right here line will forestall you from getting into "A" interior the mixture field. inner maximum Sub ComboBox1_KeyPress(ByVal sender As merchandise, ByVal e As equipment.homestead windows.varieties.KeyPressEventArgs) Handles ComboBox1.KeyPress If e.KeyChar = "A" Then e.dealt with = real end Sub

Answer 3

If var1 <> Null

(If I remember correctly)

Answer 4

If liname.Text IsNot Nothing Then
DoSomething
EndIf

Answer 5

I believe it is the following:

If Isnull(Var1) = True then

Answer 6

Try this:

if var1 <> " " then (no space between quotes)

Answer 7

hi for vb try this
if not(isnull(myvar) then
......
end if
bye for now

Answer 8

If IsDBNull(foo) Then
...
End If

Answer 9

if not ( var is nothing) then
'whatever
End if