HtmlDocument Class
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HtmlDocument Class

 

Provides top-level programmatic access to an HTML document hosted by the WebBrowser control.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

System.Object
  System.Windows.Forms.HtmlDocument

[PermissionSetAttribute(SecurityAction.LinkDemand, Name = "FullTrust")]
public sealed class HtmlDocument

NameDescription
System_CAPS_pubpropertyActiveElement

Provides the HtmlElement which currently has user input focus.

System_CAPS_pubpropertyActiveLinkColor

Gets or sets the Color of a hyperlink when clicked by a user.

System_CAPS_pubpropertyAll

Gets an instance of HtmlElementCollection, which stores all HtmlElement objects for the document.

System_CAPS_pubpropertyBackColor

Gets or sets the background color of the HTML document.

System_CAPS_pubpropertyBody

Gets the HtmlElement for the BODY tag.

System_CAPS_pubpropertyCookie

Gets or sets the HTTP cookies associated with this document.

System_CAPS_pubpropertyDefaultEncoding

Gets the encoding used by default for the current document.

System_CAPS_pubpropertyDomain

Gets or sets the string describing the domain of this document for security purposes.

System_CAPS_pubpropertyDomDocument

Gets the unmanaged interface pointer for this HtmlDocument.

System_CAPS_pubpropertyEncoding

Gets or sets the character encoding for this document.

System_CAPS_pubpropertyFocused

Gets a value indicating whether the document has user input focus.

System_CAPS_pubpropertyForeColor

Gets or sets the text color for the document.

System_CAPS_pubpropertyForms

Gets a collection of all of the <FORM> elements in the document.

System_CAPS_pubpropertyImages

Gets a collection of all image tags in the document.

System_CAPS_pubpropertyLinkColor

Gets or sets the color of hyperlinks.

System_CAPS_pubpropertyLinks

Gets a list of all the hyperlinks within this HTML document.

System_CAPS_pubpropertyRightToLeft

Gets or sets the direction of text in the current document.

System_CAPS_pubpropertyTitle

Gets or sets the text value of the <TITLE> tag in the current HTML document.

System_CAPS_pubpropertyUrl

Gets the URL describing the location of this document.

System_CAPS_pubpropertyVisitedLinkColor

Gets or sets the Color of links to HTML pages that the user has already visited.

System_CAPS_pubpropertyWindow

Gets the HtmlWindow associated with this document.

NameDescription
System_CAPS_pubmethodAttachEventHandler(String, EventHandler)

Adds an event handler for the named HTML DOM event.

System_CAPS_pubmethodCreateElement(String)

Creates a new HtmlElement of the specified HTML tag type.

System_CAPS_pubmethodDetachEventHandler(String, EventHandler)

Removes an event handler from a named event on the HTML DOM.

System_CAPS_pubmethodEquals(Object)

Tests the object for equality against the current object.(Overrides Object.Equals(Object).)

System_CAPS_pubmethodExecCommand(String, Boolean, Object)

Executes the specified command against the document.

System_CAPS_pubmethodFocus()

Sets user input focus on the current document.

System_CAPS_pubmethodGetElementById(String)

Retrieves a single HtmlElement using the element's ID attribute as a search key.

System_CAPS_pubmethodGetElementFromPoint(Point)

Retrieves the HTML element located at the specified client coordinates.

System_CAPS_pubmethodGetElementsByTagName(String)

Retrieve a collection of elements with the specified HTML tag.

System_CAPS_pubmethodGetHashCode()

Retrieves the hash code for this object.(Overrides Object.GetHashCode().)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodInvokeScript(String)

Executes an Active Scripting function defined in an HTML page.

System_CAPS_pubmethodInvokeScript(String, Object[])

Executes an Active Scripting function defined in an HTML page.

System_CAPS_pubmethodOpenNew(Boolean)

Gets a new HtmlDocument to use with the Write method.

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubmethodWrite(String)

Writes a new HTML page.

NameDescription
System_CAPS_pubeventClick

Occurs when the user clicks anywhere on the document.

System_CAPS_pubeventContextMenuShowing

Occurs when the user requests to display the document's context menu.

System_CAPS_pubeventFocusing

Occurs before focus is given to the document.

System_CAPS_pubeventLosingFocus

Occurs while focus is leaving a control.

System_CAPS_pubeventMouseDown

Occurs when the user clicks the left mouse button.

System_CAPS_pubeventMouseLeave

Occurs when the mouse is no longer hovering over the document.

System_CAPS_pubeventMouseMove

Occurs when the mouse is moved over the document.

System_CAPS_pubeventMouseOver

Occurs when the mouse is moved over the document.

System_CAPS_pubeventMouseUp

Occurs when the user releases the left mouse button.

System_CAPS_pubeventStop

Occurs when navigation to another Web page is halted.

NameDescription
System_CAPS_puboperatorSystem_CAPS_staticEquality(HtmlDocument, HtmlDocument)

Returns a value that indicates whether the specified HtmlDocument instances represent the same value.

System_CAPS_puboperatorSystem_CAPS_staticInequality(HtmlDocument, HtmlDocument)

Returns a value that indicates whether the specified HtmlDocument instances do not represent the same value.

HtmlDocument provides a managed wrapper around Internet Explorer's document object, also known as the HTML Document Object Model (DOM). You obtain an instance of HtmlDocument through the Document property of the WebBrowser control.

HTML tags inside of an HTML document can be nested inside one another. HtmlDocument thus represents a document tree, whose children are instances of the HtmlElement class. The following code example shows a simple HTML file.

<HTML>
    <BODY>
        <DIV name="Span1">Simple HTML Form</DIV>
        <FORM>
            <SPAN name="TextLabel">Enter Your Name:</SPAN>
            <INPUT type="text" size="20" name="Text1">
        </FORM>
    </BODY>
</HTML>

In this example, HtmlDocument represents the entire document inside the HTML tags. The BODY, DIV, FORM and SPAN tags are represented by individual HtmlElement objects.

There are several ways you can access the elements in this tree. Use the Body property to access the BODY tag and all of its children. The ActiveElement property gives you the HtmlElement for the element on an HTML page that has user input focus. All elements within an HTML page can have a name; the All collection provides access to each HtmlElement using its name as an index. GetElementsByTagName will return an HtmlElementCollection of all HtmlElement objects with a given HTML tag name, such as DIV or TABLE. GetElementById will return the single HtmlElement corresponding to the unique ID that you supply. GetElementFromPoint will return the HtmlElement that can be found on the screen at the supplied mouse pointer coordinates.

You can also use the Forms and Images collection to iterate through elements that represent user input forms and graphics, respectively.

HtmlDocument is based on the unmanaged interfaces implemented by Internet Explorer's DHTML DOM: IHTMLDocument, IHTMLDocument2, IHTMLDocument3, and IHTMLDocument4. Only the most frequently used properties and methods on these unmanaged interfaces are exposed by HtmlDocument. You can access all other properties and methods directly using the DomDocument property, which you can cast to the desired unmanaged interface pointer.

An HTML document may contain frames, which are different windows inside of the WebBrowser control. Each frame displays its own HTML page. The Frames collection is available through the Window property. You may also use the Window property to resize the displayed page, scroll the document, or display alerts and prompts to the user.

HtmlDocument exposes the most common events you would expect to handle when hosting HTML pages. For events not exposed directly by the interface, you can add a handler for the event using AttachEventHandler.

HTML files may contain SCRIPT tags that encapsulate code written in one of the Active Scripting languages, such as JScript or VBScript. The InvokeScript method provides for execution of properties and methods defined in a SCRIPT tag.

System_CAPS_noteNote

While most of the properties, methods, and events on HtmlDocument have kept the same names as they have on the unmanaged DOM, some have been changed for consistency with the .NET Framework.

The following code example uses data from the Northwind database to create an HTML TABLE dynamically using CreateElement. The AppendChild method is also used, first to add cells (TD elements) to rows (TR elements), then to add rows to the table, and finally to append the table to the end of the current document. The code example requires that your application has a WebBrowser control named WebBrowser1. The code should be called after a document has been loaded.

private void DisplayCustomersTable()
{
    DataSet customersSet = new DataSet();
    DataTable customersTable = null;
    SqlDataAdapter sda = new SqlDataAdapter("SELECT * FROM Customers", "Data Source=localhost;Integrated Security=SSPI;Initial Catalog=Northwind;");
    sda.Fill(customersTable);
    customersTable = customersSet.Tables[0];

    if (webBrowser1.Document != null)
    {
        HtmlElement tableRow = null;
        HtmlElement headerElem = null;

        HtmlDocument doc = webBrowser1.Document;
        HtmlElement tableElem = doc.CreateElement("TABLE");
        doc.Body.AppendChild(tableElem);

        HtmlElement tableHeader = doc.CreateElement("THEAD");
        tableElem.AppendChild(tableHeader);
        tableRow = doc.CreateElement("TR");
        tableHeader.AppendChild(tableRow);

        foreach (DataColumn col in customersTable.Columns)
        {
            headerElem = doc.CreateElement("TH");
            headerElem.InnerText = col.ColumnName;
            tableRow.AppendChild(headerElem);
        }

        // Create table rows.
        HtmlElement tableBody = doc.CreateElement("TBODY");
        tableElem.AppendChild(tableBody);
        foreach (DataRow dr in customersTable.Rows)
        {
            tableRow = doc.CreateElement("TR");
            tableBody.AppendChild(tableRow);
            foreach (DataColumn col in customersTable.Columns)
            {
                Object dbCell = dr[col];
                HtmlElement tableCell = doc.CreateElement("TD");
                if (!(dbCell is DBNull))
                {
                    tableCell.InnerText = dbCell.ToString();
                }
                tableRow.AppendChild(tableCell);
            }
        }
    }
}

.NET Framework
Available since 2.0

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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