バージョン

BeforeDropDown イベント (UltraDateTimeEditor)

ドロップダウン カレンダーがドロップダウンされる前に発生します。
シンタックス
'宣言
 
Public Event BeforeDropDown As CancelEventHandler
public event CancelEventHandler BeforeDropDown
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、CancelEventArgs 型の引数を受け取りました。次の CancelEventArgs 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
Cancel  
使用例
Imports Infragistics.Win
Imports Infragistics.Win.UltraWinEditors

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        '	Set focus to the UltraDateTimeEditor
        Me.UltraDateTimeEditor1.Focus()

        '	Set the AlwaysInEditMode property to false
        Me.UltraDateTimeEditor1.AlwaysInEditMode = False

        '	Don't allow null values
        Me.UltraDateTimeEditor1.Nullable = False

        '	Set the DateTime property to the current date
        Me.UltraDateTimeEditor1.DateTime = DateTime.Today

        '	Use the text selection-related properties to clear the edit portion
        Me.UltraDateTimeEditor1.SelectionStart = 0
        Me.UltraDateTimeEditor1.SelectionLength = Me.UltraDateTimeEditor1.Value.ToString().Length
        Me.UltraDateTimeEditor1.SelectedText = ""

    End Sub

    Private Sub UltraDateTimeEditor1_BeforeDropDown(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles UltraDateTimeEditor1.BeforeDropDown

        If (Not Me.UltraDateTimeEditor1.IsDateValid) Then
            e.Cancel = True
            MessageBox.Show("Please type a valid date.", "BeforeDropDown", MessageBoxButtons.OK)
        End If

    End Sub
using System.Diagnostics;
using Infragistics.Win;
using Infragistics.Win.UltraWinEditors;

		private void button1_Click(object sender, System.EventArgs e)
		{
			//	Set focus to the UltraDateTimeEditor
			this.ultraDateTimeEditor1.Focus();

			//	Set the AlwaysInEditMode property to false
			this.ultraDateTimeEditor1.AlwaysInEditMode = false;

			//	Don't allow null values
			this.ultraDateTimeEditor1.Nullable = false;
		
			//	Set the DateTime property to the current date
			this.ultraDateTimeEditor1.DateTime = DateTime.Today;

			//	Use the text selection-related properties to clear the edit portion
			this.ultraDateTimeEditor1.SelectionStart = 0;
			this.ultraDateTimeEditor1.SelectionLength = this.ultraDateTimeEditor1.Value.ToString().Length;
			this.ultraDateTimeEditor1.SelectedText = "";
		}	

		private void ultraDateTimeEditor1_BeforeDropDown(object sender, System.ComponentModel.CancelEventArgs e)
		{
			if ( ! this.ultraDateTimeEditor1.IsDateValid )
			{
				e.Cancel = true;

				MessageBox.Show( "Please type a valid date.", "BeforeDropDown", MessageBoxButtons.OK );
			}
		}
参照