The parameterized query which was not supplied - asp.net

Question

I keep getting this error :
The parameterized query '(#AdminEmail nvarchar(4000),#AdminPassword
nvarchar(4000))SELECT' expects the parameter '#AdminEmail', which was
not supplied.
Code:
Public Function AuthenticateAdmin() As Boolean
Dim Success As Boolean
Dim strConn As String
strConn = ConfigurationManager.ConnectionStrings("HMVDb").ToString
Dim conn As New SqlConnection(strConn.ToString())
Dim cmd As New SqlCommand("SELECT * FROM Admin WHERE AdminEmail=#AdminEmail AND Adminpassword=#Adminpassword", conn)
cmd.Parameters.AddWithValue("#AdminEmail", EMail)
cmd.Parameters.AddWithValue("#AdminPassword", Password)
Dim da As New SqlDataAdapter(cmd)
Dim ds As New DataSet
conn.Open()
da.Fill(ds, "Admin")
conn.Close()
If ds.Tables("Admin").Rows.Count > 0 Then
Dim aemail As String = ds.Tables("Admin").Rows(0).Item("AdminEmail")
Dim apass As String = ds.Tables("Admin").Rows(0).Item("AdminPassword")
Dim aid As Integer = ds.Tables("Admin").Rows(0).Item("AdminID")
Dim aname As String = ds.Tables("Admin").Rows(0).Item("AdminName")
If EMail = aemail And Password = apass Then
ID = aid ' Shopper ID that identify Ecader
Name = aname
Success = True 'Shopper is authenticated
Else
Success = False 'Authentication fail
End If
End If
'Return the authentication result to calling program
Return Success
End Function

Answer 1

Your #AdminEmail variable EMail is null. You cannot pass a null on a required parameter. Use DBNull.Value.
When using null, you are informing Sql Server that you are omitting the parameter. This can be useful for an optional parameter with a default value, but causes an error for a required parameter.
I recommend that you use always use a utility function when passing a value to a command parameter.
For example:
public static object GetDataValue(object value)
{
if(value == null)
{
return DBNull.Value;
}
return value;
}
and then use
cmd.Parameters.AddWithValue("#AdminEmail", GetDataValue(EMail))

Answer 2

Is it possible that the EMail property is null (Email is Nothing)? I think you might get that error in that case. Be sure that EMail = String.Empty or EMail = "" before you set your parameter value.
Edit: Or as another answer suggests, you can send DBNull.Value instead if you actually want nulls in your database.

Answer 3

Step through your code and see what the value of Email and Password are. Chances are they are null.