لدي الكود التالي وظهر فيه رسالة ...
Object reference not set to an instance of an object
في السطر ::
ddl.Items.Clear()
والكود كاملا ::
Dim ddl As DropDownList = CType(GridView1.FindControl("ddlConsultant"), DropDownList)
Dim ConStr As New SqlConnection
ConStr.ConnectionString = ConfigurationManager.ConnectionStrings("MyConnectionString").ConnectionString
ddl.Items.Clear()
Dim cmdConsultance As New SqlCommand("SELECT Name FROM Consultance INNER JOIN Consultant ON Consultance.ConsultanceDept = Consultant.ConsultanceDept", ConStr)
ConStr.Open()
Dim drConsultance As SqlDataReader = cmdConsultance.ExecuteReader
Do While drConsultance.Read()
ddl.Items.Add(drConsultance!Name)
Loop


