Nullable Property

Gets/sets a value which describes how an UltraTreeNodeColumn handles empty cell values.

Syntax

Visual Basic

'Declaration
 
Public Property Nullable As Nullable

C#

public Nullable Nullable {get; set;}

Remarks

The Nullable property can be used to cause the CellValidationError to fire when the end user deactivates a cell whose contents are empty by setting the property's value to 'Disallow'. This is useful in scenarios where a cell's value cannot be empty. Setting the Nullable property to 'DbNull' or 'Nothing' causes empty cells to assume a value of DbNull.Value or null (Nothing in VB), respectively. Setting the Nullable property to 'EmptyString' causes the value of empty cells to be string.Empty rather than null. When the Nullable property is set to 'Automatic', the value of an empty cell is determined by the underlying System.Data.DataColumn, if the UltraTreeNodeColumn is data bound. In that case, the DataColumn's AllowDbNull property makes the determination of how empty values are handled.

Example

The following code sample demonstrates how to use the cell editing related properties pf the UltraTreeNodeColumn to customize the cell editing functionality for a particular column:

Visual Basic

Imports Infragistics.Win
Imports Infragistics.Win.UltraWinTree

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

        Dim columnQuantity As UltraTreeNodeColumn = Me.ultraTree1.ColumnSettings.ColumnSets("Order Details").Columns("Quantity")
        Dim columnDiscount As UltraTreeNodeColumn = Me.ultraTree1.ColumnSettings.ColumnSets("Order Details").Columns("Discount")
        Dim columnProduct As UltraTreeNodeColumn = Me.ultraTree1.ColumnSettings.ColumnSets("Order Details").Columns("ProductID")

        '	Set the 'Quantity' column to have a ForeColor of blue for
        '	the active cell, allow editing, and restrict the number of
        '	characters accepted for input so that the end user cannot
        '	enter a value greater than 99. Also, don't allow null values.
        columnQuantity.ActiveCellAppearance.ForeColor = Color.Blue
        columnQuantity.AllowCellEdit = AllowCellEdit.Full
        columnQuantity.MaxLength = 2
        columnQuantity.Nullable = Nullable.Disallow

        '	make the 'Discount' column read-only.
        columnDiscount.AllowCellEdit = AllowCellEdit.ReadOnly

        '	Enable tooltips for the 'Product' column, since the
        '	name of the product might not always be fully visible.
        columnProduct.TipStyleCell = TipStyleCell.Show
    End Sub

C#

using Infragistics.Win;
using Infragistics.Win.UltraWinTree;
using System.Diagnostics;

		private void button3_Click(object sender, System.EventArgs e)
		{
			UltraTreeNodeColumn columnQuantity = this.ultraTree1.ColumnSettings.ColumnSets["Order Details"].Columns["Quantity"];
			UltraTreeNodeColumn columnDiscount = this.ultraTree1.ColumnSettings.ColumnSets["Order Details"].Columns["Discount"];
			UltraTreeNodeColumn columnProduct = this.ultraTree1.ColumnSettings.ColumnSets["Order Details"].Columns["ProductID"];

			//	Set the 'Quantity' column to have a ForeColor of blue for
			//	the active cell, allow editing, and restrict the number of
			//	characters accepted for input so that the end user cannot
			//	enter a value greater than 99. Also, don't allow null values.
			columnQuantity.ActiveCellAppearance.ForeColor = Color.Blue;
			columnQuantity.AllowCellEdit = AllowCellEdit.Full;
			columnQuantity.MaxLength = 2;
			columnQuantity.Nullable = Nullable.Disallow;

			//	make the 'Discount' column read-only.
			columnDiscount.AllowCellEdit = AllowCellEdit.ReadOnly;

			//	Enable tooltips for the 'Product' column, since the
			//	name of the product might not always be fully visible.
			columnProduct.TipStyleCell = TipStyleCell.Show;
		}

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