ComboBoxProperties.NullValueItemDisplayText Property

Gets or sets the display text for the item whose value is null.

Namespace: DevExpress.Web

Assembly: DevExpress.Web.v24.2.dll

Declaration

C#

[DefaultValue("")]
public string NullValueItemDisplayText { get; set; }

VB.NET

<DefaultValue("")>
Public Property NullValueItemDisplayText As String

Property Value

Type	Default	Description
String	String.Empty	A string value that specifies the text displayed within the item whose value is null.

Remarks

Use the NullValueItemDisplayText property to specify the text displayed within the item whose value is null. If the NullValueItemDisplayText property is not specified, the NullValueItemDisplayText property value equals the ASPxAutoCompleteBoxBase.TextFormatString property value.

Note

The NullValueItemDisplayText property is in effect if the combo box contains multiple columns.

the following example illustrates how to use the NullValueItemDisplayText property.

C#

var dataSource = new[] {
      new {  Column1 = (String)null, Column2 = (String)null, Column3=(String)null },
      new {  Column1 = "1", Column2 = "2", Column3="3" },
      new {  Column1 = "4", Column2 = "5", Column3="6" },
      new {  Column1 = "7", Column2 = "8", Column3="9" },
    };

    this.ASPxComboBox1.DataSource = dataSource;
    this.ASPxComboBox1.DataBind();

ASPX

<dx:ASPxComboBox ID="ASPxComboBox1" runat="server" AllowNull="true" ValueField="Column1" Width="300px" TextFormatString="Item {0}, {1}, {2}" NullValueItemDisplayText="Item has null value">
    <Columns>
        <dx:ListBoxColumn Caption="Column1" FieldName="Column1" Name="Column1">
        </dx:ListBoxColumn>
        <dx:ListBoxColumn Caption="Column2" FieldName="Column2" Name="Column2">
        </dx:ListBoxColumn>
        <dx:ListBoxColumn Caption="Column3" FieldName="Column3" Name="Column3">
        </dx:ListBoxColumn>
    </Columns>
</dx:ASPxComboBox>