擴展 Calendar 控制項 - DayCommand 事件
摘要
之前在「Calendar 動態產生子控制項的 Event Handler」一文中有提到如何處理 Calendar 在 DayRender 事件動態產生按鈕的事件處理，文中最後有提及，若 Calendar 控制項有類似 GridView 控制項中有 RowCommand 事件，在使用上就可以更簡化。所以本文將擴展 Calendar 控制項，新增 DayCommand 事件，就動態產生的按鈕可以可以引發 DayCommand 事件，以便做後序的命令處理。
擴展 Calendar 控制項
繼承 Calendar 命名為 TBCalendar，新增 DayCommand 事件，覆寫 RaisePostBackEvent 方法，此方法是在處理引發 PostBack 產生的控制項事件，在此判斷若 PostBack 傳入的引數為 DayCommand${0}${1} 格式 (其中 {0} 為 CommandName，{1} 為日期)，則引發 DayCommand 事件。另外新增 GetDayCommandEventReference 方法，提供取得引發 DayCommand 事件的用戶端指令碼。
''' <summary>
''' 月曆控制項。
''' </summary>
< _
Description("月曆控制項。"), _
ToolboxData("<{0}:TBCalendar runat=server></{0}:TBCalendar>") _
> _
Public Class TBCalendar
Inherits Calendar
#Region " DayCommand 事件 "
''' <summary>
''' DayCommand 事件引數。
''' </summary>
Public Class DayCommandEventArgs
Inherits System.EventArgs
Private FCommandName As String = String.Empty
Private FDate As Date = Date.MinValue
''' <summary>
''' 命令名稱。
''' </summary>
Public Property CommandName() As String
Get
Return FCommandName
End Get
Set(ByVal value As String)
FCommandName = value
End Set
End Property
''' <summary>
''' 日期。
''' </summary>
Public Property [Date]() As Date
Get
Return FDate
End Get
Set(ByVal value As Date)
FDate = value
End Set
End Property
End Class
''' <summary>
''' 日期儲存格引發的命令事件。
''' </summary>
< _
System.ComponentModel.Category(WebCommon.Category.Action), _
System.ComponentModel.Description("日期儲存格引發的命令事件。") _
> _
Public Event DayCommand(ByVal sender As Object, ByVal e As DayCommandEventArgs)
''' <summary>
''' 引發 DayCommand 事件。
''' </summary>
Protected Overridable Sub OnDayCommand(ByVal e As DayCommandEventArgs)
RaiseEvent DayCommand(Me, e)
End Sub
#End Region
''' <summary>
''' 引發 PostBack 產生的控制項事件。
''' </summary>
Protected Overrides Sub RaisePostBackEvent(ByVal eventArgument As String)
Dim oArgument() As String
Dim oEventArgs As DayCommandEventArgs
If String.Compare(eventArgument, 0, "DayCommand", 0, "DayCommand".Length, StringComparison.Ordinal) = 0 Then
oArgument = Split(eventArgument, "$")
If oArgument.Length <> 3 Then Exit Sub
oEventArgs = New DayCommandEventArgs()
oEventArgs.CommandName = oArgument(1)
oEventArgs.Date = Date.Parse(oArgument(2))
OnDayCommand(oEventArgs)
Exit Sub
End If
MyBase.RaisePostBackEvent(eventArgument)
End Sub
''' <summary>
''' 取得引發 DayCommand 事件的用戶端指令碼。
''' </summary>
''' <param name="CommandName">命令名稱。</param>
''' <param name="Date">日期。</param>
Public Function GetDayCommandEventReference(ByVal CommandName As String, ByVal [Date] As Date) As String
Dim sArgument As String
sArgument = String.Format("DayCommand${0}${1}", CommandName, [Date].ToShortDateString)
Return Me.Page.ClientScript.GetPostBackEventReference(Me, sArgument)
End Function
End Class
測試程式
在頁面上放置 TBCalendar 控制項，在 DayRender 事件中動態產生一個 HtmlButton 按鈕，並利用 GetDayCommandEventReference 方法取得引發 DayCommand 事件的用戶端指令碼。在 DayCommand 事件中將 e.CommandName 及 e.Date 輸出在頁面上。
Protected Sub Calendar1_DayRender(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DayRenderEventArgs) Handles Calendar1.DayRender
Dim oButton As HtmlButton
oButton = New HtmlButton()
oButton.InnerText = "刪除"
oButton.Attributes("onclick") = Calendar1.GetDayCommandEventReference("Delete", e.Day.Date)
e.Cell.Controls.Add(oButton)
End Sub
Protected Sub Calendar1_DayCommand(ByVal sender As Object, ByVal e As Bee.Web.WebControls.TBCalendar.DayCommandEventArgs) Handles Calendar1.DayCommand
Me.Response.Write(String.Format("DayCommand: {0} Date: {1}", e.CommandName, e.Date.ToShortDateString))
End Sub執行程式，按下某一日期的 [刪除] 鈕，就會引發其對應的 DayCommand 事件。
