DetailsViewDeleteEventArgs.Keys 屬性
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
取得一個有序的鍵欄位名稱/值對字典,包含刪除項目的鍵欄位名稱與值。
public:
property System::Collections::Specialized::IOrderedDictionary ^ Keys { System::Collections::Specialized::IOrderedDictionary ^ get(); };
public System.Collections.Specialized.IOrderedDictionary Keys { get; }
member this.Keys : System.Collections.Specialized.IOrderedDictionary
Public ReadOnly Property Keys As IOrderedDictionary
屬性值
一個 IOrderedDictionary 包含有序的關鍵字欄位名稱/值配對字典,用來匹配要刪除的項目。
範例
以下程式碼範例示範如何利用該 Keys 屬性存取被刪除紀錄的金鑰欄位值。
<%@ Page language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void CustomerDetailsView_ItemDeleting(Object sender,
DetailsViewDeleteEventArgs e)
{
// Get customer ID and name from the Keys and Values
// properties.
String keyValue = e.Keys["CustomerID"].ToString();
String customerName = e.Values["CompanyName"].ToString();
// Cancel the delete operation if the user attempts to
// delete protected record. In this example, records
// with a customer ID that starts with with "A" cannot
// be deleted.
if (keyValue.StartsWith("A"))
{
e.Cancel = true;
MessageLabel.Text = "You cannot delete " +
customerName + ". This customer is protected.";
}
else
{
MessageLabel.Text = "Row " + e.RowIndex.ToString() +
" deleted.";
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewDeleteEventArgs Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewDeleteEventArgs Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
datakeynames="CustomerID"
autogeneratedeletebutton="true"
autogeneraterows="true"
allowpaging="true"
onitemdeleting="CustomerDetailsView_ItemDeleting"
runat="server">
<fieldheaderstyle backcolor="Navy"
forecolor="White"/>
</asp:detailsview>
<asp:label id="MessageLabel"
forecolor="Red"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:sqldatasource id="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
deletecommand="Delete [Customers]
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
<%@ Page language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub CustomerDetailsView_ItemDeleting(ByVal sender As Object, _
ByVal e As DetailsViewDeleteEventArgs)
' Get customer ID and name from the Keys and Values
' properties.
Dim keyValue As String = e.Keys("CustomerID").ToString()
Dim customerName As String = e.Values("CompanyName").ToString()
' Cancel the delete operation if the user attempts to
' delete protected record. In this example, records
' with a customer ID that starts with with "A" cannot
' be deleted.
If keyValue.StartsWith("A") Then
e.Cancel = True
MessageLabel.Text = "You cannot delete " & _
customerName & ". This customer is protected."
Else
MessageLabel.Text = "Row " & e.RowIndex.ToString() & _
" deleted."
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewDeleteEventArgs Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewDeleteEventArgs Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
datakeynames="CustomerID"
autogeneratedeletebutton="true"
autogeneraterows="true"
allowpaging="true"
onitemdeleting="CustomerDetailsView_ItemDeleting"
runat="server">
<fieldheaderstyle backcolor="Navy"
forecolor="White"/>
</asp:detailsview>
<asp:label id="MessageLabel"
forecolor="Red"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the web.config file. -->
<asp:sqldatasource id="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
deletecommand="Delete [Customers]
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
備註
使用該 Keys 屬性來存取要刪除記錄的金鑰欄位或欄位的值。 例如,你可以利用這些值在刪除前驗證紀錄、將紀錄改為刪除,或記錄已刪除紀錄。
備註
此性質僅包含關鍵欄位。 要存取非鍵欄位的名稱/值對值值,請使用該 Values 屬性。
該 Keys 屬性會回傳一個實作介面的 IOrderedDictionary 物件。 該物件包含 DictionaryEntry 代表關鍵欄位的物件。
備註
作為捷徑,你也可以使用物件的 IOrderedDictionary 索引器來存取關鍵欄位的值。 使用索引器的優點是它能直接回傳關鍵欄位值。
此屬性為唯讀;不過,你可以修改它回傳物件的 IOrderedDictionary 鍵欄位值。 如果你更改了關鍵欄位的值,對應的記錄就會從資料來源中刪除。