XsdSchemaFileEditor 類別

定義

public ref class XsdSchemaFileEditor : System::Web::UI::Design::UrlEditor

public class XsdSchemaFileEditor : System.Web.UI.Design.UrlEditor

type XsdSchemaFileEditor = class
    inherit UrlEditor

Public Class XsdSchemaFileEditor
Inherits UrlEditor

繼承

Object

UITypeEditor

UrlEditor

XsdSchemaFileEditor

範例

以下程式碼範例示範如何將該類別的實例 XsdSchemaFileEditor 與包含在自訂控制項中的屬性關聯起來。 當控制屬性在設計表面被編輯時，類別 XsdSchemaFileEditor 提供使用者介面，讓使用者能選擇並編輯屬性值的 XML 結構定義檔名。

using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Web.UI;
using System.Web.UI.Design;
using System.Web.UI.Design.WebControls;
using System.Web.UI.WebControls;
using System.IO;

namespace ControlDesignerSamples.CS
{
    // Define a simple text control, derived from the 
    // System.Web.UI.WebControls.Label class.
    [
        Designer(typeof(TextControlDesigner))
    ]
    public class SimpleTextControl : Label
    {
        // Define a private member to store the file name value in the control.
        private string _filename = "";
        private string _internalText = "";

        // Define the public XML schema file property.  Indicate that the
        // property can be edited at design-time with the XsdSchemaFileEditor class.
        [EditorAttribute(typeof(System.Web.UI.Design.XsdSchemaFileEditor), 
                         typeof(System.Drawing.Design.UITypeEditor))]
        public string SchemaFileName
        {
            get
            {
                return _filename;
            }
            set
            {
                _filename = value;
            }
        }

        // Define a property that returns the timestamp
        // for the selected file.
        public string LastChanged
        {
            get
            {
                if ((_filename != null) && (_filename.Length > 0))
                {
                    if (File.Exists(_filename))
                    {
                        DateTime lastChangedStamp = File.GetLastWriteTime(_filename);
                        return lastChangedStamp.ToLongDateString();
                    }
                }
                return "";
            }
        }

        // Override the control Text property, setting the default
        // text to the LastChanged string value for the selected
        // file name.  If the file name has not been set in the
        // design view, then default to an empty string.
        public override string Text
        {
            get
            {
                if ((_internalText == "") && (LastChanged.Length > 0))
                {
                    // If the internally stored value hasn't been set,
                    // and the file name property has been set,
                    // return the last changed timestamp for the file.
                    _internalText = LastChanged;
                } 
                return _internalText;
            }

            set
            {
                if ((value != null) && (value.Length > 0))
                {
                    _internalText = value;
                }
                else {
                    _internalText = "";
                }
            }
        }
    }
}

Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Web.UI
Imports System.Web.UI.Design
Imports System.Web.UI.Design.WebControls
Imports System.Web.UI.WebControls
Imports System.IO

Namespace ControlDesignerSamples.VB


    ' Define a simple text control, derived from the 
    ' System.Web.UI.WebControls.Label class.

    <Designer(GetType(TextControlDesigner))> _
    Public Class SimpleTextControl
        Inherits Label

        ' Define a private member to store the file name value in the control.
        Private _filename As String = ""
        Private _internalText As String = ""

        ' Define the public XSD schema file name property.  Indicate that the
        ' property can be edited at design-time with the XsdSchemaFileEditor class.
        <EditorAttribute(GetType(System.Web.UI.Design.XsdSchemaFileEditor), _
                         GetType(System.Drawing.Design.UITypeEditor))> _
        Public Property SchemaFileName() As String
            Get
                Return _filename
            End Get

            Set(ByVal value As String)
                _filename = value
            End Set
        End Property

        ' Define a property that returns the timestamp
        ' for the selected file.
        Public ReadOnly Property LastChanged() As String
            Get
                If Not _filename Is Nothing AndAlso _filename.Length > 0 Then
                    If File.Exists(_filename) Then
                        Dim lastChangedStamp As DateTime
                        lastChangedStamp = File.GetLastWriteTime(_filename)
                        Return lastChangedStamp.ToLongDateString()
                    End If
                End If

                Return String.Empty

            End Get

        End Property

        ' Override the control Text property, setting the default
        ' text to the LastChanged string value for the selected
        ' file name.  If the file name has not been set in the
        ' design view, then default to an empty string.
        Public Overrides Property Text() As String
            Get
                If _internalText.Length = 0 And LastChanged.Length > 0 Then
                    ' If the internally stored value hasn't been set,
                    ' and the file name property has been set,
                    ' return the last changed timestamp for the file.

                    _internalText = LastChanged
                End If
                Return _internalText
            End Get

            Set(ByVal value As String)
                If Not value Is Nothing AndAlso value.Length > 0 Then
                    _internalText = value
                Else
                    _internalText = String.Empty
                End If

            End Set
        End Property

    End Class
End Namespace

備註

XsdSchemaFileEditor在設計時，物件用於選擇並編輯 XML 結構定義檔案（.xsd）的 URL，並將該 URL 指派給控制屬性。

使用屬性 EditorAttribute 來將 與 XsdSchemaFileEditor 屬性關聯。 當相關屬性在設計表面被編輯時，設計主機會呼叫該 EditValue 方法。 該 EditValue 方法使用的方法 BuildUrl ，該方法會顯示一個使用者介面以選擇 URL，然後回傳使用者所選的 URL。 此 GetEditStyle 方法顯示使用者介面的顯示風格。

從中 XsdSchemaFileEditor 衍生一個類別，以定義一個自訂編輯器，以設定一個 XML schema URL 屬性。 例如，導出類別可以覆寫該EditValue方法，然後用自訂BuildUrl值Filter呼叫該Caption方法。

另請參閱

• UrlEditor
• EditorAttribute