过程 'GetCategoriesInDepartment' 需要参数 '@AreaID'，但未提供该参数。

行 48： 
行 49：         connection.Open()
行 50：         Return command.ExecuteReader(CommandBehavior.CloseConnection)
行 51：     End Function
行 52：     Public Function GetCategoryDetails(ByVal categoryId As String) As CategoryDetails

GetCategoriesInDepartment函数
Public Function GetCategoriesInDepartment(ByVal departmentId As String) As SqlDataReader
Dim connection As New SqlConnection(connectionString)
Dim command As New SqlCommand("GetCategoriesInDepartment", connection)
command.CommandType = CommandType.StoredProcedure

command.Parameters.Add("@AreaID", SqlDbType.Int, 4)
command.Parameters("@AreaID").Value = departmentId

connection.Open()
Return command.ExecuteReader(CommandBehavior.CloseConnection)
End Function

GetCategoriesInDepartment存储过程
ALTER PROCEDURE GetCategoriesInDepartment

(@AreaID int)
AS
SELECT BrandID,BrandName
FROM Category
WHERE AreaID=@AreaID
RETURN
用到函数的地方
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'在此处放置初始化页的用户代码
Dim departmentId As String = Request.Params("AreaID")
Dim listIndex As String = Request.Params("CategoryIndex")

If Not listIndex Is Nothing Then
list.SelectedIndex = CInt(listIndex)
End If

Dim catalog As New Catalog
list.DataSource = catalog.GetCategoriesInDepartment(departmentId)
list.DataBind()
End Sub