HtmlTextArea Class

Reference

Definition

Namespace:: System.Web.UI.HtmlControls

Assembly:: System.Web.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Allows programmatic access to the <textarea> HTML element on the server.

public ref class HtmlTextArea : System::Web::UI::HtmlControls::HtmlContainerControl, System::Web::UI::IPostBackDataHandler

[System.Web.UI.ValidationProperty("Value")]
public class HtmlTextArea : System.Web.UI.HtmlControls.HtmlContainerControl, System.Web.UI.IPostBackDataHandler

[<System.Web.UI.ValidationProperty("Value")>]
type HtmlTextArea = class
    inherit HtmlContainerControl
    interface IPostBackDataHandler

Public Class HtmlTextArea
Inherits HtmlContainerControl
Implements IPostBackDataHandler

Inheritance: Object

Control

HtmlControl

HtmlContainerControl
HtmlTextArea

Attributes: ValidationPropertyAttribute

Implements: IPostBackDataHandler

Examples

The following code example demonstrates how to use the HtmlTextArea control to create a multiline text box.

<%@ Page Language="C#" AutoEventWireup="True" %>

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

  void SubmitBtn_Click(Object sender, EventArgs e)
  {
    Span1.InnerHtml = "You wrote: <br />" + TextArea1.Value;
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
   <title>HtmlTextArea Example</title>
</head>
<body>

   <form id="form1" runat="server">

      <h3>HtmlTextArea Example</h3>

      Enter your comments: <br />

      <textarea rows="2" cols="20" id="TextArea1" 
                runat="server"/>

      <br />

      <input type="submit"  
             value="Submit" 
             onserverclick="SubmitBtn_Click" 
             runat="server"/>

      <br />

      <span id="Span1" 
            runat="server" />

   </form>

</body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>

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

  Sub SubmitBtn_Click(ByVal sender As Object, ByVal e As EventArgs)
      
    Span1.InnerHtml = "You wrote: <br />" + TextArea1.Value
      
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
   <title>HtmlTextArea Example</title>
</head>
<body>

   <form id="form1" runat="server">

      <h3>HtmlTextArea Example</h3>

      Enter your comments: <br />

      <textarea rows="2" cols="20" id="TextArea1" 
                runat="server"/>

      <br />

      <input type="submit"  
             value="Submit" 
             onserverclick="SubmitBtn_Click" 
             runat="server"/>

      <br />

      <span id="Span1" 
            runat="server" />

   </form>

</body>
</html>

Remarks

The HtmlTextArea control corresponds to the <textarea> HTML element that allows you to create a multiline text box on a Web page. Use this control to programmatically manipulate a <textarea> HTML element.

This class allows you to control the height and width of a multiline text box by setting the Rows and Cols properties, respectively. You also can assign a name to the control by setting the Name property. To determine or specify the text in the text box, use the Value property.

The HtmlTextArea class provides a ServerChange event that allows you to perform a custom set of instructions every time the value of the text box changes between posts to the server. This event is commonly used for data validation.

Note

If you want to create a single-line text box, use the HtmlInputText control.

For a list of initial property values for an instance of HtmlTextArea, see the HtmlTextArea constructor.

Caution

This control can be used to display user input, which might include malicious client script. Check any information that is sent from a client for executable script, SQL statements, or other code before displaying it in your application. ASP.NET provides an input request validation feature to block script and HTML in user input. Validation server controls are also provided to assess user input. For more information, see Validation Server Control Syntax.

Constructors

HtmlTextArea()

Initializes a new instance of the HtmlTextArea class.

Properties

Adapter	Gets the browser-specific adapter for the control. (Inherited from Control)
AppRelativeTemplateSourceDirectory	Gets or sets the application-relative virtual directory of the Page or UserControl object that contains this control. (Inherited from Control)
Attributes	Gets a collection of all attribute name and value pairs expressed on a server control tag within the ASP.NET page. (Inherited from HtmlControl)
BindingContainer	Gets the control that contains this control's data binding. (Inherited from Control)
ChildControlsCreated	Gets a value that indicates whether the server control's child controls have been created. (Inherited from Control)
ClientID	Gets the control ID for HTML markup that is generated by ASP.NET. (Inherited from Control)
ClientIDMode	Gets or sets the algorithm that is used to generate the value of the ClientID property. (Inherited from Control)
ClientIDSeparator	Gets a character value representing the separator character used in the ClientID property. (Inherited from Control)
Cols	Gets or sets the width (in characters) of the HtmlTextArea control.
Context	Gets the HttpContext object associated with the server control for the current Web request. (Inherited from Control)
Controls	Gets a ControlCollection object that represents the child controls for a specified server control in the UI hierarchy. (Inherited from Control)
DataItemContainer	Gets a reference to the naming container if the naming container implements IDataItemContainer. (Inherited from Control)
DataKeysContainer	Gets a reference to the naming container if the naming container implements IDataKeysControl. (Inherited from Control)
DesignMode	Gets a value indicating whether a control is being used on a design surface. (Inherited from Control)
Disabled	Gets or sets a value indicating whether the HTML server control is disabled. (Inherited from HtmlControl)
EnableTheming	Gets or sets a value indicating whether themes apply to this control. (Inherited from Control)
EnableViewState	Gets or sets a value indicating whether the server control persists its view state, and the view state of any child controls it contains, to the requesting client. (Inherited from Control)
Events	Gets a list of event handler delegates for the control. This property is read-only. (Inherited from Control)
HasChildViewState	Gets a value indicating whether the current server control's child controls have any saved view-state settings. (Inherited from Control)
ID	Gets or sets the programmatic identifier assigned to the server control. (Inherited from Control)
IdSeparator	Gets the character used to separate control identifiers. (Inherited from Control)
InnerHtml	Gets or sets the content found between the opening and closing tags of the specified HTML server control. (Inherited from HtmlContainerControl)
InnerText	Gets or sets the text between the opening and closing tags of the specified HTML server control. (Inherited from HtmlContainerControl)
IsChildControlStateCleared	Gets a value indicating whether controls contained within this control have control state. (Inherited from Control)
IsTrackingViewState	Gets a value that indicates whether the server control is saving changes to its view state. (Inherited from Control)
IsViewStateEnabled	Gets a value indicating whether view state is enabled for this control. (Inherited from Control)
LoadViewStateByID	Gets a value indicating whether the control participates in loading its view state by ID instead of index. (Inherited from Control)
Name	Gets or sets the unique identifier name for the HtmlTextArea control.
NamingContainer	Gets a reference to the server control's naming container, which creates a unique namespace for differentiating between server controls with the same ID property value. (Inherited from Control)
Page	Gets a reference to the Page instance that contains the server control. (Inherited from Control)
Parent	Gets a reference to the server control's parent control in the page control hierarchy. (Inherited from Control)
RenderingCompatibility	Gets a value that specifies the ASP.NET version that rendered HTML will be compatible with. (Inherited from Control)
Rows	Gets or sets the height (in characters) of the HtmlTextArea control.
Site	Gets information about the container that hosts the current control when rendered on a design surface. (Inherited from Control)
SkinID	Gets or sets the skin to apply to the control. (Inherited from Control)
Style	Gets a collection of all cascading style sheet (CSS) properties applied to a specified HTML server control in the ASP.NET file. (Inherited from HtmlControl)
TagName	Gets the element name of a tag that contains a `runat=server` attribute and value pair. (Inherited from HtmlControl)
TemplateControl	Gets or sets a reference to the template that contains this control. (Inherited from Control)
TemplateSourceDirectory	Gets the virtual directory of the Page or UserControl that contains the current server control. (Inherited from Control)
UniqueID	Gets the unique, hierarchically qualified identifier for the server control. (Inherited from Control)
ValidateRequestMode	Gets or sets a value that indicates whether the control checks client input from the browser for potentially dangerous values. (Inherited from Control)
Value	Gets or sets the text entered in the HtmlTextArea control.
ViewState	Gets a dictionary of state information that allows you to save and restore the view state of a server control across multiple requests for the same page. (Inherited from Control)
ViewStateIgnoresCase	Gets a value that indicates whether the HtmlControl view state is case-sensitive. (Inherited from HtmlControl)
ViewStateMode	Gets or sets the view-state mode of this control. (Inherited from Control)
Visible	Gets or sets a value that indicates whether a server control is rendered as UI on the page. (Inherited from Control)

Methods

AddedControl(Control, Int32)	Called after a child control is added to the Controls collection of the Control object. (Inherited from Control)
AddParsedSubObject(Object)	Notifies the HtmlTextArea control that an object was parsed and adds the object to the HtmlTextArea control's ControlCollection object.
ApplyStyleSheetSkin(Page)	Applies the style properties defined in the page style sheet to the control. (Inherited from Control)
BeginRenderTracing(TextWriter, Object)	Begins design-time tracing of rendering data. (Inherited from Control)
BuildProfileTree(String, Boolean)	Gathers information about the server control and delivers it to the Trace property to be displayed when tracing is enabled for the page. (Inherited from Control)
ClearCachedClientID()	Sets the cached ClientID value to `null`. (Inherited from Control)
ClearChildControlState()	Deletes the control-state information for the server control's child controls. (Inherited from Control)
ClearChildState()	Deletes the view-state and control-state information for all the server control's child controls. (Inherited from Control)
ClearChildViewState()	Deletes the view-state information for all the server control's child controls. (Inherited from Control)
ClearEffectiveClientIDMode()	Sets the ClientIDMode property of the current control instance and of any child controls to Inherit. (Inherited from Control)
CreateChildControls()	Called by the ASP.NET page framework to notify server controls that use composition-based implementation to create any child controls they contain in preparation for posting back or rendering. (Inherited from Control)
CreateControlCollection()	Creates a new ControlCollection object to hold the child controls (both literal and server) of the server control. (Inherited from HtmlContainerControl)
DataBind()	Binds a data source to the invoked server control and all its child controls. (Inherited from Control)
DataBind(Boolean)	Binds a data source to the invoked server control and all its child controls with an option to raise the DataBinding event. (Inherited from Control)
DataBindChildren()	Binds a data source to the server control's child controls. (Inherited from Control)
Dispose()	Enables a server control to perform final clean up before it is released from memory. (Inherited from Control)
EndRenderTracing(TextWriter, Object)	Ends design-time tracing of rendering data. (Inherited from Control)
EnsureChildControls()	Determines whether the server control contains child controls. If it does not, it creates child controls. (Inherited from Control)
EnsureID()	Creates an identifier for controls that do not have an identifier assigned. (Inherited from Control)
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
FindControl(String, Int32)	Searches the current naming container for a server control with the specified `id` and an integer, specified in the `pathOffset` parameter, which aids in the search. You should not override this version of the FindControl method. (Inherited from Control)
FindControl(String)	Searches the current naming container for a server control with the specified `id` parameter. (Inherited from Control)
Focus()	Sets input focus to a control. (Inherited from Control)
GetAttribute(String)	Gets the value of the named attribute on the HtmlControl control. (Inherited from HtmlControl)
GetDesignModeState()	Gets design-time data for a control. (Inherited from Control)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetRouteUrl(Object)	Gets the URL that corresponds to a set of route parameters. (Inherited from Control)
GetRouteUrl(RouteValueDictionary)	Gets the URL that corresponds to a set of route parameters. (Inherited from Control)
GetRouteUrl(String, Object)	Gets the URL that corresponds to a set of route parameters and a route name. (Inherited from Control)
GetRouteUrl(String, RouteValueDictionary)	Gets the URL that corresponds to a set of route parameters and a route name. (Inherited from Control)
GetType()	Gets the Type of the current instance. (Inherited from Object)
GetUniqueIDRelativeTo(Control)	Returns the prefixed portion of the UniqueID property of the specified control. (Inherited from Control)
HasControls()	Determines if the server control contains any child controls. (Inherited from Control)
HasEvents()	Returns a value indicating whether events are registered for the control or any child controls. (Inherited from Control)
IsLiteralContent()	Determines if the server control holds only literal content. (Inherited from Control)
LoadControlState(Object)	Restores control-state information from a previous page request that was saved by the SaveControlState() method. (Inherited from Control)
LoadPostData(String, NameValueCollection)	Processes the postback data for the HtmlTextArea control.
LoadViewState(Object)	Restores the HtmlContainerControl control's view state from a previous page request that was saved by the SaveViewState() method. (Inherited from HtmlContainerControl)
MapPathSecure(String)	Retrieves the physical path that a virtual path, either absolute or relative, maps to. (Inherited from Control)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
OnBubbleEvent(Object, EventArgs)	Determines whether the event for the server control is passed up the page's UI server control hierarchy. (Inherited from Control)
OnDataBinding(EventArgs)	Raises the DataBinding event. (Inherited from Control)
OnInit(EventArgs)	Raises the Init event. (Inherited from Control)
OnLoad(EventArgs)	Raises the Load event. (Inherited from Control)
OnPreRender(EventArgs)	Raises the PreRender event.
OnServerChange(EventArgs)	Raises the ServerChange event of the HtmlTextArea control. This allows you to provide a custom handler for the event.
OnUnload(EventArgs)	Raises the Unload event. (Inherited from Control)
OpenFile(String)	Gets a Stream used to read a file. (Inherited from Control)
RaiseBubbleEvent(Object, EventArgs)	Assigns any sources of the event and its information to the control's parent. (Inherited from Control)
RaisePostDataChangedEvent()	Calls the OnServerChange(EventArgs) method to signal the HtmlTextArea control that the state of the control has changed.
RemovedControl(Control)	Called after a child control is removed from the Controls collection of the Control object. (Inherited from Control)
Render(HtmlTextWriter)	Renders the HtmlContainerControl control to the specified HtmlTextWriter object. (Inherited from HtmlContainerControl)
RenderAttributes(HtmlTextWriter)	Renders the HtmlTextArea control's attributes to the specified HtmlTextWriter object.
RenderBeginTag(HtmlTextWriter)	Renders the opening HTML tag of the control into the specified HtmlTextWriter object. (Inherited from HtmlControl)
RenderChildren(HtmlTextWriter)	Outputs the content of a server control's children to a provided HtmlTextWriter object, which writes the content to be rendered on the client. (Inherited from Control)
RenderControl(HtmlTextWriter, ControlAdapter)	Outputs server control content to a provided HtmlTextWriter object using a provided ControlAdapter object. (Inherited from Control)
RenderControl(HtmlTextWriter)	Outputs server control content to a provided HtmlTextWriter object and stores tracing information about the control if tracing is enabled. (Inherited from Control)
RenderEndTag(HtmlTextWriter)	Renders the closing tag for the HtmlContainerControl control to the specified HtmlTextWriter object. (Inherited from HtmlContainerControl)
ResolveAdapter()	Gets the control adapter responsible for rendering the specified control. (Inherited from Control)
ResolveClientUrl(String)	Gets a URL that can be used by the browser. (Inherited from Control)
ResolveUrl(String)	Converts a URL into one that is usable on the requesting client. (Inherited from Control)
SaveControlState()	Saves any server control state changes that have occurred since the time the page was posted back to the server. (Inherited from Control)
SaveViewState()	Saves any server control view-state changes that have occurred since the time the page was posted back to the server. (Inherited from Control)
SetAttribute(String, String)	Sets the value of the named attribute on the HtmlControl control. (Inherited from HtmlControl)
SetDesignModeState(IDictionary)	Sets design-time data for a control. (Inherited from Control)
SetRenderMethodDelegate(RenderMethod)	Assigns an event handler delegate to render the server control and its content into its parent control. (Inherited from Control)
SetTraceData(Object, Object, Object)	Sets trace data for design-time tracing of rendering data, using the traced object, the trace data key, and the trace data value. (Inherited from Control)
SetTraceData(Object, Object)	Sets trace data for design-time tracing of rendering data, using the trace data key and the trace data value. (Inherited from Control)
ToString()	Returns a string that represents the current object. (Inherited from Object)
TrackViewState()	Causes tracking of view-state changes to the server control so they can be stored in the server control's StateBag object. This object is accessible through the ViewState property. (Inherited from Control)

Events

DataBinding	Occurs when the server control binds to a data source. (Inherited from Control)
Disposed	Occurs when a server control is released from memory, which is the last stage of the server control lifecycle when an ASP.NET page is requested. (Inherited from Control)
Init	Occurs when the server control is initialized, which is the first step in its lifecycle. (Inherited from Control)
Load	Occurs when the server control is loaded into the Page object. (Inherited from Control)
PreRender	Occurs after the Control object is loaded but prior to rendering. (Inherited from Control)
ServerChange	Occurs when the content of the HtmlTextArea control changes between posts to the server.
Unload	Occurs when the server control is unloaded from memory. (Inherited from Control)

Explicit Interface Implementations

IAttributeAccessor.GetAttribute(String)	For a description of this member, see GetAttribute(String). (Inherited from HtmlControl)
IAttributeAccessor.SetAttribute(String, String)	For a description of this member, see SetAttribute(String, String). (Inherited from HtmlControl)
IControlBuilderAccessor.ControlBuilder	For a description of this member, see ControlBuilder. (Inherited from Control)
IControlDesignerAccessor.GetDesignModeState()	For a description of this member, see GetDesignModeState(). (Inherited from Control)
IControlDesignerAccessor.SetDesignModeState(IDictionary)	For a description of this member, see SetDesignModeState(IDictionary). (Inherited from Control)
IControlDesignerAccessor.SetOwnerControl(Control)	For a description of this member, see SetOwnerControl(Control). (Inherited from Control)
IControlDesignerAccessor.UserData	For a description of this member, see UserData. (Inherited from Control)
IDataBindingsAccessor.DataBindings	For a description of this member, see DataBindings. (Inherited from Control)
IDataBindingsAccessor.HasDataBindings	For a description of this member, see HasDataBindings. (Inherited from Control)
IExpressionsAccessor.Expressions	For a description of this member, see Expressions. (Inherited from Control)
IExpressionsAccessor.HasExpressions	For a description of this member, see HasExpressions. (Inherited from Control)
IParserAccessor.AddParsedSubObject(Object)	For a description of this member, see AddParsedSubObject(Object). (Inherited from Control)
IPostBackDataHandler.LoadPostData(String, NameValueCollection)	For a description of this member, see LoadPostData(String, NameValueCollection).
IPostBackDataHandler.RaisePostDataChangedEvent()	For a description of this member, see RaisePostDataChangedEvent().

Extension Methods

FindDataSourceControl(Control)	Returns the data source that is associated with the data control for the specified control.
FindFieldTemplate(Control, String)	Returns the field template for the specified column in the specified control's naming container.
FindMetaTable(Control)	Returns the metatable object for the containing data control.

Applies to

Jaa