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BoundField.NullDisplayText Property

Gets or sets the caption displayed for a field when the field's value is null.

Namespace:  System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

public virtual string NullDisplayText { get; set; }

Property Value

Type: System.String
The caption displayed for a field when the field's value is null. The default is an empty string (""), which indicates that this property is not set.

Sometimes a field's value is stored as null in the data source. You can specify a custom caption to display for fields that have a null value by setting the NullDisplayText property. If this property is not set, null field values are displayed as empty strings (""). When a record is being updated or inserted in a data-bound control, if the user enters the value specified by this property (other than an empty string) for a field in a data-bound control, that value is automatically converted to null in the data source.

NoteNote:

To convert an empty string field value to a null value, set the ConvertEmptyStringToNull property to true.

The following code example demonstrates how to use the NullDisplayText property to specify a custom caption to display for null field values.

<%@ Page language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>BoundField NullDisplayText Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>BoundField NullDisplayText Example</h3>

      <asp:gridview id="DiscountsGridView" 
        datasourceid="DiscountsSqlDataSource" 
        autogeneratecolumns="false"
        runat="server">

        <columns>

          <asp:boundfield datafield="discounttype"
            nulldisplaytext="No Data"
            headertext="Discount Type"/>

          <asp:boundfield datafield="stor_id"
            nulldisplaytext="No Data"
            headertext="Store ID"/> 

          <asp:boundfield datafield="lowqty"
            nulldisplaytext="No Data"
            headertext="Low Quantity"/>

          <asp:boundfield datafield="highqty"
            nulldisplaytext="No Data"
            headertext="High Quantity"/>

          <asp:boundfield datafield="discount"
            nulldisplaytext="No Data"
            dataformatstring="{0:F4}%" 
            itemstyle-horizontalalign="Right" 
            headertext="Discount"/>     

        </columns>

      </asp:gridview>

      <!-- This example uses Microsoft SQL Server and connects -->
      <!-- to the Pubs sample database.                        -->
      <asp:sqldatasource id="DiscountsSqlDataSource"  
        selectcommand="SELECT [discounttype], [stor_id], [lowqty], [highqty], [discount] FROM [discounts]"
        connectionstring="<%$ ConnectionStrings:PubsConnectionString%>"
        runat="server">
      </asp:sqldatasource>

    </form>
  </body>
</html>

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0
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