This documentation is archived and is not being maintained.

ImageField Constructor

Note: This constructor is new in the .NET Framework version 2.0.

Initializes a new instance of the ImageField class.

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

public ImageField ()
public ImageField ()
public function ImageField ()

Use this constructor to initialize a new instance of the ImageField class. This constructor is commonly used when adding fields to a dynamically created data-bound control.

To dynamically add an ImageField object to a data-bound control, create a new ImageField object, set its properties, and then add it to the data-bound control's field collection. For example, if you are using the GridView control, add the ImageField object to the Columns collection.

NoteNote

Although you can dynamically add fields to a data-bound control, it is strongly recommended that fields be statically declared and then shown or hidden, as appropriate. Statically declaring all your fields reduces the size of the view state for the parent data-bound control.

The following example demonstrates how to use this constructor to dynamically add an ImageField object to the Columns collection of a GridView control.


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

<script runat="server">

  void Page_Load(Object sender, EventArgs e)
  {

    if (!IsPostBack)
    {
      
      // Dynamically create a GridView control.
      GridView employeesView = new GridView();
      employeesView.ID = "EmployeesGrid";
      employeesView.AutoGenerateColumns = false;
      employeesView.DataSourceID = "EmployeeSource";

      // Dynamically create field columns to display the desired
      // fields from the data source.

      // Create an ImageField object to display an employee's photo.
      ImageField photoImageField = new ImageField();
      photoImageField.DataImageUrlField = "PhotoPath";
      photoImageField.AlternateText = "Employee Photo";
      photoImageField.NullDisplayText = "No image on file.";
      photoImageField.HeaderText = "Photo";
      photoImageField.ReadOnly = true;

      // Create a BoundField object to display an employee's last name.
      BoundField lastNameBoundField = new BoundField();
      lastNameBoundField.DataField = "LastName";
      lastNameBoundField.HeaderText = "Last Name";

      // Create a BoundField object to display an employee's first name.
      BoundField firstNameBoundField = new BoundField();
      firstNameBoundField.DataField = "FirstName";
      firstNameBoundField.HeaderText = "First Name";

      // Add the field columns to the Fields collection of the
      // GridView control.
      employeesView.Columns.Add(photoImageField);
      employeesView.Columns.Add(lastNameBoundField);
      employeesView.Columns.Add(firstNameBoundField);
      
      // Add the GridView control to the Controls collection
      // of the PlaceHolder control. 
      GridViewPlaceHolder.Controls.Add(employeesView);

    }

  }

</script>

<html>
  <body>
    <form runat="server">
        
      <h3>ImageField Constructor Example</h3>
                  
      <asp:placeholder id="GridViewPlaceHolder"
        runat="server"/>            
           
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="EmployeeSource"
        selectcommand="Select [EmployeeID], [LastName], [FirstName], [PhotoPath] From [Employees]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>


Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

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

.NET Framework

Supported in: 2.0
Show: