DataControlField Class
Serves as the base class for all data control field types, which represent a column of data in tabular data-bound controls such as DetailsView and GridView.
Assembly: System.Web (in System.Web.dll)
[TypeConverterAttribute(typeof(ExpandableObjectConverter))] [AspNetHostingPermissionAttribute(SecurityAction::LinkDemand, Level = AspNetHostingPermissionLevel::Minimal)] [AspNetHostingPermissionAttribute(SecurityAction::InheritanceDemand, Level = AspNetHostingPermissionLevel::Minimal)] public ref class DataControlField abstract : IStateManager, IDataSourceViewSchemaAccessor
The DataControlField class serves as the base class for all data control field types. Data control fields are used by data-bound controls to represent a field of data, similar to how a DataGridColumn object represents a type of column in the DataGrid control.
Use the classes that are derived from DataControlField to control how a field of data is displayed in a data-bound control such as DetailsView or GridView. The following table lists the different data control field types provided by ASP.NET.
Column field type | Description |
|---|---|
Displays the value of a field in a data source as text. | |
Displays a command button in a data-bound control. Depending on the control, this allows you to display either a row or a column with a custom button control, such as an Add or a Remove button. | |
Displays a check box in a data-bound control. This data control field type is commonly used to display fields with a Boolean value. | |
Displays built-in command buttons to perform edit, insert, or delete operations in a data-bound control. | |
Displays the value of a field in a data source as a hyperlink. This data control field type allows you to bind a second field to the hyperlink's URL. | |
Displays an image in a data-bound control. | |
Displays user-defined content in a data-bound control according to a specified template. |
You can also extend the DataControlField and BoundField classes to create your own data control field types.
The DataControlField class provides many properties that determine how user interface (UI) elements are presented in the data-bound control. Not every control uses every available data control field property when rendering a UI. For example, the DetailsView control, which displays the data control fields as rows, includes a header item for each data control field, but no footer item. Therefore, the FooterText and FooterStyle properties are ignored by the DetailsView control. The GridView control, however, uses the FooterText and FooterStyle properties if the ShowFooter property is set to true. Similarly, the data control field properties affect the presentation of UI elements depending on what the element is. The ItemStyle property is always applied to the field. If the type derived from DataControlField contains a control, as in the ButtonField or CheckBoxField classes, the ControlStyle property is applied to the field.
The following code example demonstrates how to use BoundField and ButtonField objects, which are derived from DataControlField, to display rows in a DetailsView control. The DetailsView control has the AutoGenerateRows property set to false, which enables it to display a subset of the data returned by the SelectCommand property.
The following code example demonstrates how to extend the BoundField class to create a custom bound field that can be used in a GridView control. Similar to the CheckBoxField class, the RadioButtonField class represents a column of true or false data. However, although the data that the CheckBoxField class is bound to can be any set of true or false values, the set of data that the RadioButtonField class is bound to can have only one true value at any given time. This example demonstrates how to implement the ExtractValuesFromCell and InitializeCell methods, two important methods of all classes derived from DataControlField.
The following code example demonstrates how to use the RadioButtonField class, which is provided in the previous example, in a GridView control. In this example, the GridView control displays data for a sports team. The player data is maintained in a data table that includes an ID column, columns for the player names, and a true or false column that identifies the captain of the team. The RadioButtonField class is used to display which team member is the current team captain. The GridView control can be edited to choose a new team captain or to change other player information.
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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.