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MailFileEditor Class

Note: This class is new in the .NET Framework version 2.0.

Provides a user interface for selecting and editing a mail file name for a property at design time.

Namespace: System.Web.UI.Design
Assembly: System.Design (in system.design.dll)

public class MailFileEditor : UrlEditor
public class MailFileEditor extends UrlEditor
public class MailFileEditor extends UrlEditor

The MailFileEditor class is an UITypeEditor object that can be used at design time to select and edit a mail file name as a string, and assign the string to a control property. For example, the EmbeddedMailObject control uses the MailFileEditor class at design time to set the value of the Path property.

Use the EditorAttribute attribute to associate the MailFileEditor with a property. When the associated property is edited in the design surface, the designer host calls the EditValue method. The EditValue method displays a dialog box for selecting a mail file name from a filtered list of files, and returns the file name that is selected by the user. The GetEditStyle method indicates the display style of the user interface.

Derive a class from the MailFileEditor to define a custom editor for a mail file name property. For example, a derived class can override the EditValue method, and display an OpenFileDialog instance with a custom mail file filter or title.

The following code example demonstrates how to associate an instance of the MailFileEditor class with a property that is contained within a custom control. When the control property is edited in the design surface, the MailFileEditor class provides the user interface to select and edit a mail file name for the property value.

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;

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 file name property.  Indicate that the
        // property can be edited at design-time with the MailFileEditor class.
        [EditorAttribute(typeof(System.Web.UI.Design.MailFileEditor), 
                         typeof(System.Drawing.Design.UITypeEditor))]
        public string MailFileName
        {
            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 (System.IO.File.Exists(_filename))
                    {
                        DateTime lastChangedStamp = System.IO.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 = "";
                }
            }
        }
    }

}

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0
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