CodeBehind方式設定GridView欄寬、置中

使用GridView中內建的編輯功能預設是沒有設定欄寬的，因此會造成編輯時的TextBox將欄位撐開的問題：

在GridView的RowDataBound事件中以CodeBehind設定欄位寬度與文字置中：

Protected Sub GridView_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView.RowDataBound

        '設定欄位寬度

  GridView.Columns(1).ItemStyle.Width = 80

        GridView.Columns(1).ControlStyle.Width = 80

        '設定文字置中

   GridView.Columns(1).ItemStyle.HorizontalAlign = HorizontalAlign.Center

    End Sub

ItemStyle.Width：普通模式欄位寬度
ControlStyle.Width ：編輯模式欄位寬度

設定後結果：
 

補充：
以For迴圈方式設定GridView中所有欄位寬度

Protected Sub GridView_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView.RowDataBound

        Dim i As Integer

        For i As Integer = 0 To GridView.Columns.Count - 1

            GridView.Columns(i).ItemStyle.Width = 80

        Next

End Sub