過程返回錯誤：無法強制System.Int32 System.Int32 []

Question

我寫了一個程序，應該從我的數據庫返回一個值。要返回的值是一個整數。這裏是我的代碼：

Private Sub btnSelectProducts_Click(sender As Object, e As EventArgs) Handles btnSelectProducts.Click 

    Try 

    'Connection Variables 
    Dim cnn As SqlCeConnection 
    Dim connectionString As String 

    'Connect to database 
    connectionString = "Data Source=|DataDirectory|\Database\ContactsAndInventory.sdf" 
    cnn = New SqlCeConnection(connectionString) 

    Dim Stream As New MemoryStream() 
    cnn.Open() 

    Dim command As New SqlCeCommand("SELECT CATEGORY_ID FROM PRODUCT_CATEGORY WHERE (CATEGORY_NAME = @CATEGORY_NAME)", cnn) 
    command.Parameters.AddWithValue("@CATEGORY_NAME", txtCategoryName.Text) 

     Dim catId As Integer() = CType(command.ExecuteScalar(), Integer())'Error Here 

    MsgBox(catId) 

     cnn.Close() 

    Catch ex As Exception 

     MsgBox(ex.ToString) 

    End Try 


End Sub 

我收到錯誤：

System.InvalidCastException: Unable to cast objct to type System.Int32 to type System.Int32[] 

在想不通爲什麼，現場是一個整場，我試圖返回的值是一個整數。我究竟做錯了什麼？

Answer 1

我找出我的錯誤：

Dim catId = Convert.ToInt32(command.ExecuteScalar())