ValueObjectChanging イベント

コントロールの Value プロパティまたは ValueObject プロパティが変更される直前に発生します。

シンタックス

Visual Basic

'宣言
 
Public Event ValueObjectChanging As Infragistics.Win.UltraWinEditors.TrackBarValueChangingEventHandler

C#

public event Infragistics.Win.UltraWinEditors.TrackBarValueChangingEventHandler ValueObjectChanging

イベント データ

イベント ハンドラが、このイベントに関連するデータを含む、Infragistics.Win.UltraWinEditors.TrackBarValueChangingEventArgs 型の引数を受け取りました。次の TrackBarValueChangingEventArgs プロパティには、このイベントの固有の情報が記載されます。

プロパティ	解説
NewValue
OldValue
Source

使用例

Visual Basic

Imports Infragistics.Win.UltraWinEditors

    Private Sub UltraTrackBar1_ValueObjectChanging(ByVal sender As System.Object, ByVal e As Infragistics.Win.TrackBarValueChangingEventArgs) Handles UltraTrackBar1.ValueObjectChanging

        Dim trackBar As UltraTrackBar = CType(sender, UltraTrackBar)

        ' This sample code will prevent the thumb from snapping to a value unless that value is a 
        ' multiple of a number.

        Const multiple As Integer = 5

        ' Is the value changing due to the dragging of the thumb?
        If (e.Source = TrackBarActionSource.Thumb) Then
            ' Cast the NewValue to an Integer. 
            ' Under some circumstances, NewValue could be Nothing. Or it could be any object, since
            ' the control supports DataFilters. 
            ' In this case, we will assume that nulls and DataFilters are not being used.
            Dim newValue As Integer = CType(e.NewValue, Integer)

            Dim extra As Integer = newValue Mod multiple

            ' Is the value not evenly divisible by 5. 
            If (extra <> 0) Then

                newValue += (multiple - extra)

                ' Make sure the value doesn't go past the MaxValue. 
                e.NewValue = Math.Min(newValue, trackBar.MaxValue)
            End If
        End If

    End Sub

C#

using Infragistics.Win.UltraWinEditors;

        private void ultraTrackBar1_ValueObjectChanging(object sender, Infragistics.Win.TrackBarValueChangingEventArgs e)
        {
            UltraTrackBar trackBar = sender as UltraTrackBar;

            // This sample code will prevent the thumb from snapping to a value unless that value is a 
            // multiple of a number.

            const int multiple = 5;
            
            // Is the value changing due to the dragging of the thumb?
            if (e.Source == TrackBarActionSource.Thumb)
            {                
                // Cast the NewValue to an int. 
                // Under some circumstances, NewValue could be null. Or it could be any object, since
                // the control supports DataFilters. 
                // In this case, we will assume that nulls and DataFilters are not being used.
                int newValue = (int)e.NewValue;

                int extra = newValue % multiple;
                    
                // Is the value not evenly divisible by 5. 
                if (extra != 0)
                {                    
                    newValue += (multiple - extra);

                    // Make sure the value doesn't go past the MaxValue. 
                    e.NewValue = Math.Min(newValue, trackBar.MaxValue);
                }
            }
        }