CheckBoxField Class
Definition
Important
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Represents a Boolean field that is displayed as a check box in a data-bound control.
public ref class CheckBoxField : System::Web::UI::WebControls::BoundFieldpublic class CheckBoxField : System.Web.UI.WebControls.BoundFieldtype CheckBoxField = class
inherit BoundFieldPublic Class CheckBoxField
Inherits BoundField- Inheritance
Examples
The following code example demonstrates how to use a CheckBoxField object in a GridView control to display a field from a Microsoft SQL Server data source with a Boolean data type.
<%@ 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>CheckBoxField Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>CheckBoxField Example</h3>
<asp:gridview id="AuthorsGridView"
datasourceid="AuthorsSqlDataSource"
autogeneratecolumns="False"
runat="server">
<columns>
<asp:boundfield datafield="au_lname"
headertext="Last Name"/>
<asp:checkboxfield datafield="contract"
text="Contract"
headertext="Contract"/>
</columns>
</asp:gridview>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Pubs sample database. -->
<asp:sqldatasource id="AuthorsSqlDataSource"
selectcommand="SELECT [au_lname], [au_fname], [address], [city], [state], [zip], [contract] FROM [authors]"
connectionstring="server=localhost;database=pubs;integrated security=SSPI"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
<%@ Page language="VB" %>
<!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>CheckBoxField Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>CheckBoxField Example</h3>
<asp:gridview id="AuthorsGridView"
datasourceid="AuthorsSqlDataSource"
autogeneratecolumns="False"
runat="server">
<columns>
<asp:boundfield datafield="au_lname"
headertext="Last Name"/>
<asp:checkboxfield datafield="contract"
text="Contract"
headertext="Contract"/>
</columns>
</asp:gridview>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Pubs sample database. -->
<asp:sqldatasource id="AuthorsSqlDataSource"
selectcommand="SELECT [au_lname], [au_fname], [address], [city], [state], [zip], [contract] FROM [authors]"
connectionstring="server=localhost;database=pubs;integrated security=SSPI"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
Remarks
The CheckBoxField class is used by data-bound controls (such as GridView and DetailsView) to display the value of a Boolean data field in a check box. The CheckBoxField object is displayed differently depending on the data-bound control in which it is used. For example, the GridView control displays a CheckBoxField object as a column, while the DetailsView control displays it as a row.
Note
A check box is disabled (read-only) until the data-bound control displays a record that contains the check box in edit mode. For more information on how to put a record into edit mode, see the documentation for the parent control that contains the CheckBoxField object.
To specify the field to display in a CheckBoxField object, set the DataField property with the field's name.
Note
Because a check box can display only a selected or an unselected state, a CheckBoxField object can be bound only to a field with a Boolean data type or a string that can be parsed by Parse.
You can display a caption next to each check box by setting the Text property. A CheckBoxField object is hidden in a data-bound control when the Visible property is set to false. To prevent the value of a field from being modified in edit mode, set the ReadOnly property to true. In data-bound controls that support inserting records (such as the DetailsView control), you can hide a CheckBoxField object in insert mode by setting the InsertVisible property to false.
You can customize the header and footer sections of a CheckBoxField object. To display a caption in the header or footer sections, set the HeaderText or FooterText properties, respectively. Instead of displaying text in the header section, you can display an image by setting the HeaderImageUrl property. The header section can be hidden in the CheckBoxField object by setting the ShowHeader property to false.
Note
Some data-bound controls (such as the GridView control) can show or hide only the entire header section of the control. These data-bound controls do not support the ShowHeader property for an individual bound field. To show or hide the entire header section of a data-bound control (if available), use the control's ShowHeader property.
You also can customize the appearance of the CheckBoxField object (font color, background color, and so on) by setting the style properties for the different parts of the field. The following table lists the different style properties.
| Style property | Description |
|---|---|
| ControlStyle | The style settings for the child Web server controls of the CheckBoxField object. |
| FooterStyle | The style settings for the footer section of the CheckBoxField object. |
| HeaderStyle | The style settings for the header section of the CheckBoxField object. |
| ItemStyle | The style settings for the data items in the CheckBoxField object. |
Constructors
| CheckBoxField() |
Initializes a new instance of the CheckBoxField class. |
Properties
| AccessibleHeaderText |
Gets or sets text that is rendered as the |
| ApplyFormatInEditMode |
Overrides the ApplyFormatInEditMode property. This property is not supported by the CheckBoxField class. |
| Control |
Gets a reference to the data control that the DataControlField object is associated with. (Inherited from DataControlField) |
| ControlStyle |
Gets the style of any Web server controls contained by the DataControlField object. (Inherited from DataControlField) |
| ConvertEmptyStringToNull |
Overrides the ConvertEmptyStringToNull property. This property is not supported by the CheckBoxField class. |
| DataField |
Gets or sets the name of the data field to bind to the CheckBoxField object. |
| DataFormatString |
Gets or sets the string that specifies the display format for the value of the field. This property is not supported by the CheckBoxField class. |
| DesignMode |
Gets a value indicating whether a data control field is currently viewed in a design-time environment. (Inherited from DataControlField) |
| FooterStyle |
Gets or sets the style of the footer of the data control field. (Inherited from DataControlField) |
| FooterText |
Gets or sets the text that is displayed in the footer item of a data control field. (Inherited from DataControlField) |
| HeaderImageUrl |
Gets or sets the URL of an image that is displayed in the header item of a data control field. (Inherited from DataControlField) |
| HeaderStyle |
Gets or sets the style of the header of the data control field. (Inherited from DataControlField) |
| HeaderText |
Gets or sets the text that is displayed in the header of a data control. (Inherited from BoundField) |
| HtmlEncode |
Overrides the HtmlEncode property. This property is not supported by the CheckBoxField class. |
| HtmlEncodeFormatString |
Gets or sets a value that indicates whether the formatted text should be HTML encoded before it is displayed. |
| InsertVisible |
Gets a value indicating whether the DataControlField object is visible when its parent data-bound control is in insert mode. (Inherited from DataControlField) |
| IsTrackingViewState |
Gets a value indicating whether the DataControlField object is saving changes to its view state. (Inherited from DataControlField) |
| ItemStyle |
Gets the style of any text-based content displayed by a data control field. (Inherited from DataControlField) |
| NullDisplayText |
Gets or sets the text displayed for a field when the field's value is |
| ReadOnly |
Gets or sets a value indicating whether the value of the field can be modified in edit mode. (Inherited from BoundField) |
| ShowHeader |
Gets or sets a value indicating whether the header item of a data control field is rendered. (Inherited from DataControlField) |
| SortExpression |
Gets or sets a sort expression that is used by a data source control to sort data. (Inherited from DataControlField) |
| SupportsHtmlEncode |
Gets a Boolean value indicating whether the control supports HTML encoding. |
| Text |
Gets or sets the caption to display next to each check box in a CheckBoxField object. |
| ValidateRequestMode |
Gets or sets a value that determines whether the control validates client input or not. (Inherited from BoundField) |
| ViewState |
Gets a dictionary of state information that allows you to save and restore the view state of a DataControlField object across multiple requests for the same page. (Inherited from DataControlField) |
| Visible |
Gets or sets a value indicating whether a data control field is rendered. (Inherited from DataControlField) |
Methods
| CloneField() |
Creates a duplicate copy of the current DataControlField-derived object. (Inherited from DataControlField) |
| CopyProperties(DataControlField) |
Copies the properties of the current CheckBoxField object to the specified DataControlField object. |
| CreateField() |
Creates an empty CheckBoxField object. |
| Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
| ExtractValuesFromCell(IOrderedDictionary, DataControlFieldCell, DataControlRowState, Boolean) |
Fills the specified IDictionary object with the values from the specified DataControlFieldCell object. |
| FormatDataValue(Object, Boolean) |
Formats the specified field value for a cell in the BoundField object. (Inherited from BoundField) |
| GetDesignTimeValue() |
Retrieves the value used for the field's value when rendering the CheckBoxField object in a designer. |
| GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| GetValue(Control) |
Retrieves the value of the field bound to the BoundField object. (Inherited from BoundField) |
| Initialize(Boolean, Control) |
Initializes the BoundField object. (Inherited from BoundField) |
| InitializeCell(DataControlFieldCell, DataControlCellType, DataControlRowState, Int32) |
Initializes the specified TableCell object to the specified row state. (Inherited from BoundField) |
| InitializeDataCell(DataControlFieldCell, DataControlRowState) |
Initializes the specified DataControlFieldCell object to the specified row state. |
| LoadViewState(Object) |
Restores the previously stored view-state information for this field. (Inherited from BoundField) |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| OnDataBindField(Object, EventArgs) |
Binds the value of a field to a check box in the CheckBoxField object. |
| OnFieldChanged() |
Raises the |
| SaveViewState() |
Saves the changes made to the DataControlField view state since the time the page was posted back to the server. (Inherited from DataControlField) |
| ToString() |
Returns a string that represents this DataControlField object. (Inherited from DataControlField) |
| TrackViewState() |
Causes the DataControlField object to track changes to its view state so they can be stored in the control's ViewState property and persisted across requests for the same page. (Inherited from DataControlField) |
| ValidateSupportsCallback() |
Determines whether the controls contained in a CheckBoxField object support callbacks. |
Explicit Interface Implementations
| IDataSourceViewSchemaAccessor.DataSourceViewSchema |
Gets or sets the schema associated with this DataControlField object. (Inherited from DataControlField) |
| IStateManager.IsTrackingViewState |
Gets a value indicating whether the DataControlField object is saving changes to its view state. (Inherited from DataControlField) |
| IStateManager.LoadViewState(Object) |
Restores the data control field's previously saved view state. (Inherited from DataControlField) |
| IStateManager.SaveViewState() |
Saves the changes made to the DataControlField view state since the time the page was posted back to the server. (Inherited from DataControlField) |
| IStateManager.TrackViewState() |
Causes the DataControlField object to track changes to its view state so they can be stored in the control's ViewState property and persisted across requests for the same page. (Inherited from DataControlField) |
