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ButtonField Constructor

  • Reference

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Initializes a new instance of the ButtonField class.

C# 
public ButtonField();

Examples

The following code example demonstrates how to use the M:System.Web.UI.WebControls.ButtonField.#ctor constructor to add a ButtonField object dynamically to a GridView control.

ASP.NET (C#) 

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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void CustomersGridView_RowCommand(Object sender, GridViewCommandEventArgs e)
  {
  
    // If multiple ButtonField column fields are used, use the
    // CommandName property to determine which button was clicked.
    if(e.CommandName=="Select")
    {
    
      // Convert the row index stored in the CommandArgument
      // property to an Integer.
      int index = Convert.ToInt32(e.CommandArgument);    
    
      // Get the last name of the selected Customer from the appropriate
      // cell in the GridView control.
      GridViewRow selectedRow = CustomersGridView.Rows[index];
      TableCell contactCell = selectedRow.Cells[1];
      string contact = contactCell.Text;  
    
      // Display the selected Customer.
      Message.Text = "You selected " + contact + ".";
      
    }
    
  }

  void Page_Load(Object sender, EventArgs e)
  {
  
    // The field columns need to be created only the first time
    // the page is loaded.
    if (!IsPostBack)
    {
      
      // Dynamically create field columns to display the desired
      // fields from the data source.
      
      // Create a ButtonField object to allow the user to 
      // select an Customer.
      ButtonField selectButtonField = new ButtonField ();

      selectButtonField.ButtonType = ButtonType.Button;
      selectButtonField.CommandName = "Select";
      selectButtonField.HeaderText = "Select Customer";
      selectButtonField.Text = "Select";

      // Create a BoundField object to display an Customer's last name.
      BoundField contactNameBoundField = new BoundField();

      contactNameBoundField.DataField = "ContactName";
      contactNameBoundField.HeaderText = "Contact Name";

      // Create a BoundField object to display an Customer's first name.
      BoundField contactTitleBoundField = new BoundField();

      contactTitleBoundField.DataField = "ContactTitle";
      contactTitleBoundField.HeaderText = "Contact Title";

      // Add the field columns to the Columns collection of the
      // GridView control.
      CustomersGridView.Columns.Add (selectButtonField);
      CustomersGridView.Columns.Add(contactNameBoundField);
      CustomersGridView.Columns.Add(contactTitleBoundField);
      
    }
    
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ButtonField Constructor Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>ButtonField Constructor Example</h3>

      <asp:label id="Message"
        forecolor="Red"
        runat="server"
        AssociatedControlID="CustomersGridView"/>

      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSqlDataSource" 
        autogeneratecolumns="False"
        onrowcommand="CustomersGridView_RowCommand"
        runat="server">                
      </asp:gridview>
            
        <!-- This example uses Microsoft SQL Server and connects -->
        <!-- to the Northwind sample database.                   -->
        <asp:sqldatasource id="CustomersSqlDataSource"  
          selectcommand="Select [CustomerID], [CompanyName], [ContactName], [ContactTitle] From [Customers]"
          connectionstring="<%$ ConnectionStrings:NorthWindConnection%>"
          runat="server">
        </asp:sqldatasource>
            
    </form>
  </body>
</html>

Remarks

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

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

Poznámka

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

Applies to

Produkt Verzie
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

See also