Infragistics logo
메뉴
.NET and JavaScript UI Controls
Version

ColumnHeaderInitializing Event

Fired immediately before the child elements are initialized for a ColumnHeaderUIElement, giving listeners the opportunity to change the text and/or image that is displayed.
Syntax
'Declaration
 
Public Event ColumnHeaderInitializing As ColumnHeaderInitializingHandler
public event ColumnHeaderInitializingHandler ColumnHeaderInitializing
Event Data

The event handler receives an argument of type ColumnHeaderInitializingEventArgs containing data related to this event. The following ColumnHeaderInitializingEventArgs properties provide information specific to this event.

PropertyDescription
AppearanceData Returns or sets an AppearanceData struct which can be used to override the resolves appearance for a particular header.
DateTimeInterval Returns the DateTimeInterval instance for which the column header is being displayed.
DateTimeRange Returns a DateTimeRange instance which describes the date/time range spanned by the header.
HeaderElement Returns the ColumnHeaderUIElement instance that is being initialized.
Text Returns or sets the text that will be displayed on the header.
Example
The following code sample demonstrates how to use the ColumnHeaderInitializing event to display an analog clock in place of the header text to depict the time spanned by that header:

For an overview of how to handle events in Visual Basic or Visual C#, see Event Handlers in Visual Basic and Visual C#. For specific information and code examples illustrating how to consume events in your application, see Consuming Events in the .NET Framework Developer's Guide.

Imports System.Collections.Generic
Imports Infragistics.Win
Imports Infragistics.Win.UltraWinSchedule
Imports System.Diagnostics

    Public Sub ShowClocks(ByVal control As UltraTimelineView)
        '  Don't show any additional intervals
        control.AdditionalIntervals.Clear()

        '  Create a new TimeInterval with 15-minute intervals
        '  and assign it to the PrimaryInterval property.
        Dim primaryInterval As New TimeInterval(15, TimeIntervalUnits.Minutes)
        control.PrimaryInterval = primaryInterval

        '  Set the image alignment to middle/center
        control.ColumnHeaderAppearance.ImageHAlign = HAlign.Center
        control.ColumnHeaderAppearance.ImageVAlign = VAlign.Middle

        '  Set ColumnHeaderImageSize to a size that is large
        '  enough to display an analog clock image set the
        '  ColumnWidth property to a slightly larger size.
        control.ColumnHeaderImageSize = ClockSize
        control.ColumnWidth = ClockSize.Width + Padding

        '  Handle the ColumnHeaderInitializing event so we can
        '  show an image on the header instead of the text, and
        '  the ColumnHeaderToolTipDisplaying event so we can force
        '  a tooltip to be displayed.
        AddHandler control.ColumnHeaderInitializing, AddressOf Me.OnColumnHeaderInitializing
        AddHandler control.ColumnHeaderToolTipDisplaying, AddressOf Me.OnColumnHeaderToolTipDisplaying
    End Sub


    Private Sub OnColumnHeaderToolTipDisplaying(ByVal sender As Object, ByVal e As ColumnHeaderToolTipDisplayingEventArgs)

        '  If this is a primary interval header, show the start time
        '  in a tooltip, since there is no text on the header.
        If Not e.HeaderElement Is Nothing AndAlso e.HeaderElement.DateTimeInterval.IsPrimaryInterval Then
            Dim toolTipInfo As ToolTipInfo = e.ToolTipInfo
            toolTipInfo.ToolTipText = e.HeaderElement.DateTimeRange.StartDateTime.ToString(TimeInterval.ShortTimePattern)
            e.ToolTipInfo = toolTipInfo
        End If
    End Sub

    Private Sub OnColumnHeaderInitializing(ByVal sender As Object, ByVal e As ColumnHeaderInitializingEventArgs)

        If (e.DateTimeInterval.IsPrimaryInterval) Then
            '  Create an image of an analog clock, depicting the
            '  start time for this header, and assign it to the
            '  Image property of the e.AppearanceData
            Dim time As TimeSpan = e.DateTimeRange.StartDateTime.TimeOfDay
            Dim bmp As Bitmap = ClockImage.GetImage(time, ClockSize, Color.Black, Color.White)
            Dim appData As AppearanceData = New AppearanceData()
            appData.Image = bmp
            e.AppearanceData = appData

            '  Assign a space character to the text, so that
            '  nothing appears, but a tooltip can still be displayed
            e.Text = " "
        End If
    End Sub
using System.Collections.Generic;
using Infragistics.Win;
using Infragistics.Win.UltraWinSchedule;
using System.Diagnostics;

    public void ShowClocks( UltraTimelineView control )
    {
        //  Don't show any additional intervals
        control.AdditionalIntervals.Clear();

        //  Create a new TimeInterval with 15-minute intervals
        //  and assign it to the PrimaryInterval property.
        TimeInterval primaryInterval = new TimeInterval(15, TimeIntervalUnits.Minutes);
        control.PrimaryInterval = primaryInterval;

        //  Set the image alignment to middle/center
        control.ColumnHeaderAppearance.ImageHAlign = HAlign.Center;
        control.ColumnHeaderAppearance.ImageVAlign = VAlign.Middle;

        //  Set ColumnHeaderImageSize to a size that is large
        //  enough to display an analog clock image; set the
        //  ColumnWidth property to a slightly larger size,
        //  and set MinimumColumnResizeWidth as well so the user
        //  can't resize the headers any smaller than that size.
        control.ColumnHeaderImageSize = ClockSize;
        control.ColumnWidth = ClockSize.Width + Padding;
        control.MinimumColumnResizeWidth = control.ColumnWidth;

        //  Handle the ColumnHeaderInitializing event so we can
        //  show an image on the header instead of the text, and
        //  the ColumnHeaderToolTipDisplaying event so we can force
        //  a tooltip to be displayed.
        control.ColumnHeaderInitializing += new ColumnHeaderInitializingHandler(this.OnColumnHeaderInitializing);
        control.ColumnHeaderToolTipDisplaying += new ColumnHeaderToolTipDisplayingHandler(OnColumnHeaderToolTipDisplaying);
    }

    private void OnColumnHeaderToolTipDisplaying(object sender, ColumnHeaderToolTipDisplayingEventArgs e)
    {
        //  If this is a primary interval header, show the start time
        //  in a tooltip, since there is no text on the header.
        if ( e.HeaderElement != null && e.HeaderElement.DateTimeInterval.IsPrimaryInterval )
        {
            ToolTipInfo toolTipInfo = e.ToolTipInfo;
            toolTipInfo.ToolTipText = e.HeaderElement.DateTimeRange.StartDateTime.ToString(TimeInterval.ShortTimePattern);
            e.ToolTipInfo = toolTipInfo;
        }
    }

    private void OnColumnHeaderInitializing(object sender, ColumnHeaderInitializingEventArgs e)
    {
        if ( e.DateTimeInterval.IsPrimaryInterval )
        {
            //  Create an image of an analog clock, depicting the
            //  start time for this header, and assign it to the
            //  Image property of the e.AppearanceData
            TimeSpan time = e.DateTimeRange.StartDateTime.TimeOfDay;
            Bitmap bmp = ClockImage.GetImage( time, ClockSize, Color.Black, Color.White );
            AppearanceData appData = new AppearanceData();
            appData.Image = bmp;
            e.AppearanceData = appData;

            //  Assign a space character to the text, so that
            //  nothing appears, but a tooltip can still be displayed
            e.Text = " ";
        }
    }
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

See Also