UrlPropertyAttribute 类

定义

public ref class UrlPropertyAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Property)]
public sealed class UrlPropertyAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Property)>]
type UrlPropertyAttribute = class
    inherit Attribute

Public NotInheritable Class UrlPropertyAttribute
Inherits Attribute

继承

Object

Attribute

UrlPropertyAttribute

属性

AttributeUsageAttribute

示例

下面的代码示例演示了实现特定于 URL 的属性的类。 在此代码示例中，特性 UrlPropertyAttribute 应用于 TargetUrl 类的 CustomHyperLinkControl 属性。 属性为 ASP.NET 文件设置特定的文件筛选器。

public class CustomHyperLinkControl : WebControl
{
    public CustomHyperLinkControl() { }

    // The TargetUrl property represents the URL that 
    // the custom hyperlink control navigates to.
    [UrlProperty("*.aspx")]
    public string TargetUrl
    {
        get
        {
            string s = (string)ViewState["TargetUrl"];
            return ((s == null) ? String.Empty : s);
        }
        set
        {
            ViewState["TargetUrl"] = value;
        }
    }

    // The Text property represents the visible text that 
    // the custom hyperlink control is displayed with.        
    public virtual string Text
    {
        get
        {
            string s = (string)ViewState["Text"];
            return ((s == null) ? String.Empty : s);
        }
        set
        {
            ViewState["Text"] = value;
        }
    }

    // Implement method to render the control.
}

Public Class CustomHyperLinkControl
    Inherits WebControl

    Public Sub New()
    End Sub

    ' The TargetUrl property represents the URL that 
    ' the custom hyperlink control navigates to.        
    <UrlProperty("*.aspx")> _
    Public Property TargetUrl() As String
        Get
            Dim s As String = CStr(ViewState("TargetUrl"))
            If (s Is Nothing) Then
                Return String.Empty
            Else
                Return s
            End If
        End Get
        Set(ByVal value As String)
            ViewState("TargetUrl") = value
        End Set
    End Property

    ' The Text property represents the visible text that 
    ' the custom hyperlink control is displayed with.                
    Public Overridable Property [Text]() As String
        Get
            Dim s As String = CStr(ViewState("Text"))
            If (s Is Nothing) Then
                Return String.Empty
            Else
                Return s
            End If
        End Get
        Set(ByVal value As String)
            ViewState("Text") = value
        End Set
    End Property

    ' Implement method to render the control.

End Class

注解

特性 UrlPropertyAttribute 是应用于表示 URL 的控件属性的属性。 除了将字符串属性标记为表示 URL 之外， UrlPropertyAttribute 特性还 Filter 定义用于标识可用于筛选属性的特定文件类型的属性。