PersistChildrenAttribute.IsDefaultAttribute 方法
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。
傳回值，指出 PersistChildrenAttribute 類別目前執行個體的值是否為衍生類別的預設值。
public:
override bool IsDefaultAttribute();public override bool IsDefaultAttribute ();override this.IsDefaultAttribute : unit -> boolPublic Overrides Function IsDefaultAttribute () As Boolean傳回
如果 PersistChildrenAttribute 目前執行個體的值是預設執行個體，則為 true，否則為 false。
範例
下列程式碼範例示範如何使用 IsDefaultAttribute 方法來判斷類別的目前實例是否與預設實例 PersistChildrenAttribute 相同。
此程式碼範例是提供給 類別之較大範例的 PersistChildrenAttribute 一部分。
<%@ Page Language="C#" %>
<%@ Register TagPrefix="AspSample" Assembly="Samples.AspNet.CS.Controls" Namespace="PersistChildrenSamples" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
// Create two new employees and add them to the custom control.
Employee e1 = new Employee("Employee 1", "Title 1", "Alias 1");
Employee e2 = new Employee("Employee 2", "Title 2", "Alias 2");
CollectionPropertyControl1.Employees.Add(e1);
CollectionPropertyControl1.Employees.Add(e2);
// Verify attribute values.
PersistChildrenAttribute p =
(PersistChildrenAttribute)Attribute.GetCustomAttribute(typeof(CollectionPropertyControl),
typeof(PersistChildrenAttribute));
StringBuilder sb = new StringBuilder();
sb.Append("The Persist property is " + p.Persist.ToString() + "<br />");
sb.Append("The UseCustomPersistence property is " + p.UsesCustomPersistence.ToString() + "<br />");
sb.Append("The IsDefault method returns " + p.IsDefaultAttribute().ToString());
Message.Text = sb.ToString();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>PersistChildrenAttribute</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Label ID="Message"
runat="server"/>
<AspSample:CollectionPropertyControl id="CollectionPropertyControl1"
runat="server">
</AspSample:CollectionPropertyControl>
</div>
</form>
</body>
</html>
<%@ Page Language="VB" %>
<%@ Register TagPrefix="AspSample" Assembly="Samples.AspNet.VB.Controls" Namespace="PersistChildrenSampleVB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
' Create two new employees and add them to the custom control.
Dim e1 As New Employee("Employee 1", "Title 1", "Alias 1")
Dim e2 As New Employee("Employee 2", "Title 2", "Alias 2")
CollectionPropertyControl1.Employees.Add(e1)
CollectionPropertyControl1.Employees.Add(e2)
' Verify attribute values.
Dim p As PersistChildrenAttribute = _
Attribute.GetCustomAttribute(GetType(CollectionPropertyControl), _
GetType(PersistChildrenAttribute))
Dim sb As New StringBuilder()
sb.Append("The Persist property is " & p.Persist.ToString() & "<br />")
sb.Append("The UseCustomPersistence property is " & p.UsesCustomPersistence.ToString() & "<br />")
sb.Append("The IsDefault method returns " & p.IsDefaultAttribute().ToString())
Message.Text = sb.ToString()
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>PersistChildrenAttribute</title>
</head>
<body>
<form id="Form1" runat="server">
<div>
<asp:Label ID="Message"
runat="server"/>
<AspSample:CollectionPropertyControl id="CollectionPropertyControl1"
runat="server">
</AspSample:CollectionPropertyControl>
</div>
</form>
</body>
</html>
