In this topic:

• Introduction

• Templates

• Binding to Data

• Data Operations

• Customizing the User Interface

• Events

• Accessibility

• Applying CSS Styles

• Declarative Syntax

Introduction

The System.Web.UI.WebControls.FormView control is used to display a single record from a data source. It is similar to the System.Web.UI.WebControls.DetailsView control, except it displays user-defined templates instead of row fields. Creating your own templates gives you greater flexibility in controlling how the data is displayed. The System.Web.UI.WebControls.FormView control supports the following features:

• Binding to data source controls, such as System.Web.UI.WebControls.SqlDataSource and System.Web.UI.WebControls.ObjectDataSource.

• Built-in inserting capabilities.

• Built-in updating and deleting capabilities.

• Built-in paging capabilities.

• Programmatic access to the System.Web.UI.WebControls.FormView object model to dynamically set properties, handle events, and so on.

• Customizable appearance through user-defined templates, themes, and styles.

Templates

For the System.Web.UI.WebControls.FormView control to display content, you need to create templates for the different parts of the control. Most templates are optional; however, you must create a template for the mode in which the control is configured. For example, a System.Web.UI.WebControls.FormView control that supports inserting records must have an insert item template defined. The following table lists the different templates that you can create.

To display the value of a field in an item template, use a data binding expression. For more information on data binding expressions, see Data Binding Expression Syntax.

Input controls in the edit item template and insert item template can be bound to the fields of a data source by using a two-way binding expression. This allows the System.Web.UI.WebControls.FormView control to automatically extract the values of the input control for an update or insert operation. Two-way binding expressions also allow input controls in an edit item template to automatically display the original field values. For more information on two-way binding expressions, see ASP.NET Data Binding.

Binding to Data

The System.Web.UI.WebControls.FormView control can be bound to a data source control (such as System.Web.UI.WebControls.SqlDataSource, System.Web.UI.WebControls.ObjectDataSource, or System.Web.UI.WebControls.AccessDataSource) or to any data source collection that implements the IEnumerable interface, such as System.Data.DataView, ArrayList, List`1, or other collection types. Use one of the following methods to bind the System.Web.UI.WebControls.FormView control to the appropriate data source type:

• To bind to a data source control, set the DataBoundControl.DataSourceID property of the System.Web.UI.WebControls.FormView control to the System.Web.UI.Control.ID value of the data source control. The System.Web.UI.WebControls.FormView control automatically binds to the specified data source control and can take advantage of the data source control's capabilities to perform inserting, updating, deleting, and paging functionality. This is the preferred method to bind to data.

• To bind to a data source that implements the IEnumerable interface, programmatically set the BaseDataBoundControl.DataSource property of the System.Web.UI.WebControls.FormView control to the data source and then call the BaseDataBoundControl.DataBind method. When using this method, the System.Web.UI.WebControls.FormView control does not provide built-in inserting, updating, deleting, and paging functionality. You need to provide this functionality by using the appropriate event.

For more information on data binding, see Accessing Data with ASP.NET.

Data Operations

The System.Web.UI.WebControls.FormView control provides many built-in capabilities that allow the user to update, delete, insert, and page through items in the control. When the System.Web.UI.WebControls.FormView control is bound to a data source control, the System.Web.UI.WebControls.FormView control can take advantage of the data source control's capabilities and provide automatic updating, deleting, inserting, and paging functionality.

Because the System.Web.UI.WebControls.FormView control uses templates, it does not provide a way to automatically generate command buttons to perform updating, deleting, or inserting operations. You must manually include these command buttons in the appropriate template. The System.Web.UI.WebControls.FormView control recognizes certain buttons that have their CommandName properties set to specific values. The following table lists the command buttons that the System.Web.UI.WebControls.FormView control recognizes.

Unlike the Delete button (which deletes the displayed record immediately), when the Edit or New button is clicked, the System.Web.UI.WebControls.FormView control goes into edit or insert mode, respectively. In edit mode, the content contained in the FormView.EditItemTemplate property is displayed for the current data item. Typically, the edit item template is defined such that the Edit button is replaced with an Update and a Cancel button. Input controls that are appropriate for the field's data type (such as a System.Web.UI.WebControls.TextBox or a System.Web.UI.WebControls.CheckBox control) are also usually displayed with a field's value for the user to modify. Clicking the Update button updates the record in the data source, while clicking the Cancel button abandons any changes.

Likewise, the content contained in the FormView.InsertItemTemplate property is displayed for the data item when the control is in insert mode. The insert item template is typically defined such that the New button is replaced with an Insert and a Cancel button, and empty input controls are displayed for the user to enter the values for the new record. Clicking the Insert button inserts the record in the data source, while clicking the Cancel button abandons any changes.

The System.Web.UI.WebControls.FormView control provides a paging feature, which allows the user to navigate to other records in the data source. When enabled, a pager row is displayed in the System.Web.UI.WebControls.FormView control that contains the page navigation controls. To enable paging, set the FormView.AllowPaging property to true. You can customize the pager row by setting the properties of objects contained in the FormView.PagerStyle and the FormView.PagerSettings property. Instead of using the built-in pager row UI, you can create your own UI by using the FormView.PagerTemplate property.

Customizing the User Interface

You can customize the appearance of the System.Web.UI.WebControls.FormView control by setting the style properties for the different parts of the control. The following table lists the different style properties.

Events

The System.Web.UI.WebControls.FormView control provides several events that you can program against. This allows you to run a custom routine whenever an event occurs. The following table lists the events supported by the System.Web.UI.WebControls.FormView control.

Accessibility

For information about how to configure this control so that it generates markup that conforms to accessibility standards, see Accessibility in Visual Studio 2010 and ASP.NET 4 and ASP.NET Controls and Accessibility.

Applying CSS Styles

The System.Web.UI.WebControls.FormView control lets you specify CSS style rules in markup. If you use templates to customize the appearance of the System.Web.UI.WebControls.FormView control, you can specify CSS styles in the markup in the templates. In that case, no extra outer table is required. You can prevent the table from being rendered by setting the FormView.RenderOuterTable property to false.

Declarative Syntax

<asp:FormView
    AccessKey="string"
    AllowPaging="True|