ListView.ItemInserting 事件
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。
當要求插入作業時,但是在 ListView 控制項執行插入之前發生。
public:
event EventHandler<System::Web::UI::WebControls::ListViewInsertEventArgs ^> ^ ItemInserting;
public event EventHandler<System.Web.UI.WebControls.ListViewInsertEventArgs> ItemInserting;
member this.ItemInserting : EventHandler<System.Web.UI.WebControls.ListViewInsertEventArgs>
Public Custom Event ItemInserting As EventHandler(Of ListViewInsertEventArgs)
事件類型
範例
下列範例示範如何新增 事件的事件處理程式 ItemInserting 。
重要
此範例包含接受使用者輸入的控件,這是潛在的安全性威脅。 根據預設,ASP.NET Web 網頁會驗證使用者輸入未包含指令碼或 HTML 項目。 如需詳細資訊,請參閱 Script Exploits Overview (指令碼攻擊概觀)。
<%@ 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 Page_Load()
{
Message.Text = String.Empty;
}
//<Snippet2>
void ContactsListView_ItemInserting(Object sender, ListViewInsertEventArgs e)
{
// Iterate through the values to verify if they are not empty.
foreach (DictionaryEntry de in e.Values)
{
if (de.Value == null)
{
Message.Text = "Cannot insert an empty value.";
e.Cancel = true;
}
}
}
//</Snippet2>
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView.ItemInserting Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView.ItemInserting Example</h3>
<asp:Label ID="Message"
ForeColor="Red"
runat="server"/>
<br/>
<asp:ListView ID="ContactsListView"
DataSourceID="ContactsDataSource"
DataKeyNames="ContactID"
OnItemInserting="ContactsListView_ItemInserting"
InsertItemPosition="LastItem"
runat="server">
<LayoutTemplate>
<table cellpadding="2" border="1" runat="server" id="tblProducts" width="640px">
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="PeopleDataPager" PageSize="12">
<Fields>
<asp:NextPreviousPagerField
ShowFirstPageButton="true" ShowLastPageButton="true"
FirstPageText="|<< " LastPageText=" >>|"
NextPageText=" > " PreviousPageText=" < " />
</Fields>
</asp:DataPager>
</LayoutTemplate>
<ItemTemplate>
<tr runat="server">
<td valign="top">
<asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
</tr>
</ItemTemplate>
<InsertItemTemplate>
<tr style="background-color:#B0C4DE">
<td valign="top">
<asp:Label runat="server" ID="FirstNameLabel"
AssociatedControlID="FirstNameTextBox" Text="First Name"/>
<asp:TextBox ID="FirstNameTextBox" runat="server"
Text='<%#Bind("FirstName") %>' MaxLength="50" /><br />
<asp:Label runat="server" ID="LastNameLabel"
AssociatedControlID="LastNameTextBox" Text="Last Name" />
<asp:TextBox ID="LastNameTextBox" runat="server"
Text='<%#Bind("LastName") %>' MaxLength="50" /><br />
<asp:Label runat="server" ID="EmailLabel"
AssociatedControlID="EmailTextBox" Text="Email" />
<asp:TextBox ID="EmailTextBox" runat="server"
Text='<%#Bind("EmailAddress") %>' MaxLength="50" /><br />
</td>
<td>
<asp:LinkButton ID="InsertButton" runat="server" CommandName="Insert" Text="Insert" />
</td>
</tr>
</InsertItemTemplate>
</asp:ListView>
<asp:SqlDataSource ID="ContactsDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
SelectCommand="SELECT [ContactID], [FirstName], [LastName], [EmailAddress]
FROM Person.Contact"
InsertCommand="INSERT INTO Person.Contact
([FirstName], [LastName], [EmailAddress], [PasswordHash], [PasswordSalt])
Values(@FirstName, @LastName, @EmailAddress, '', '');
SELECT @ContactID = SCOPE_IDENTITY()">
<InsertParameters>
<asp:Parameter Name="FirstName" />
<asp:Parameter Name="LastName" />
<asp:Parameter Name="EmailAddress" />
<asp:Parameter Name="ContactID" Type="Int32" Direction="Output" />
</InsertParameters>
</asp:SqlDataSource>
</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 Page_Load()
Message.Text = String.Empty
End Sub
'<Snippet2>
Sub ContactsListView_ItemInserting(ByVal sender As Object, _
ByVal e As ListViewInsertEventArgs)
' Iterate through the values to verify if they are not empty.
For Each de As DictionaryEntry In e.Values
If de.Value Is Nothing Then
Message.Text = "Cannot insert an empty value."
e.Cancel = True
End If
Next
End Sub
'</Snippet2>
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView.ItemInserting Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView.ItemInserting Example</h3>
<asp:Label ID="Message"
ForeColor="Red"
runat="server"/>
<br/>
<asp:ListView ID="ContactsListView"
DataSourceID="ContactsDataSource"
DataKeyNames="ContactID"
OnItemInserting="ContactsListView_ItemInserting"
InsertItemPosition="LastItem"
runat="server">
<LayoutTemplate>
<table cellpadding="2" border="1" runat="server" id="tblProducts" width="640px">
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="PeopleDataPager" PageSize="12">
<Fields>
<asp:NextPreviousPagerField
ShowFirstPageButton="true" ShowLastPageButton="true"
FirstPageText="|<< " LastPageText=" >>|"
NextPageText=" > " PreviousPageText=" < " />
</Fields>
</asp:DataPager>
</LayoutTemplate>
<ItemTemplate>
<tr runat="server">
<td valign="top">
<asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
</tr>
</ItemTemplate>
<InsertItemTemplate>
<tr style="background-color:#B0C4DE">
<td valign="top">
<asp:Label runat="server" ID="FirstNameLabel"
AssociatedControlID="FirstNameTextBox" Text="First Name"/>
<asp:TextBox ID="FirstNameTextBox" runat="server"
Text='<%#Bind("FirstName") %>' MaxLength="50" /><br />
<asp:Label runat="server" ID="LastNameLabel"
AssociatedControlID="LastNameTextBox" Text="Last Name" />
<asp:TextBox ID="LastNameTextBox" runat="server"
Text='<%#Bind("LastName") %>' MaxLength="50" /><br />
<asp:Label runat="server" ID="EmailLabel"
AssociatedControlID="EmailTextBox" Text="Email" />
<asp:TextBox ID="EmailTextBox" runat="server"
Text='<%#Bind("EmailAddress") %>' MaxLength="50" /><br />
</td>
<td>
<asp:LinkButton ID="InsertButton" runat="server" CommandName="Insert" Text="Insert" />
</td>
</tr>
</InsertItemTemplate>
</asp:ListView>
<asp:SqlDataSource ID="ContactsDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
SelectCommand="SELECT [ContactID], [FirstName], [LastName], [EmailAddress]
FROM Person.Contact"
InsertCommand="INSERT INTO Person.Contact
([FirstName], [LastName], [EmailAddress], [PasswordHash], [PasswordSalt])
Values(@FirstName, @LastName, @EmailAddress, '', '');
SELECT @ContactID = SCOPE_IDENTITY()">
<InsertParameters>
<asp:Parameter Name="FirstName" />
<asp:Parameter Name="LastName" />
<asp:Parameter Name="EmailAddress" />
<asp:Parameter Name="ContactID" Type="Int32" Direction="Output" />
</InsertParameters>
</asp:SqlDataSource>
</form>
</body>
</html>
備註
ListView當單擊範本中的 InsertItemTemplate [插入] 按鈕或InsertNewItem呼叫 方法,但在控件插入記錄之前ListView,控件就會引發 ItemInserting 事件。 (Insert 按鈕是一個按鈕控件,其 CommandName 屬性設定為 “Insert”。) 這可讓您在發生此事件時執行自定義例程,例如在數據源中插入記錄之前,先以 HTML 編碼方式傳送記錄的值。
ListViewInsertEventArgs物件會傳遞至事件處理程式,可讓您判斷傳送至ListView控件的選擇性命令自變數值。 它也可讓您指出應該取消插入作業。 若要取消插入工作,請將 Cancel 屬性設定為 true
。 您可以使用 屬性來讀取或修改新記錄 Values 的域值。
如需如何處理事件的詳細資訊,請參閱 處理和引發事件。