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HtmlElement.OffsetParent Property

  • Reference

Definition

Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms.dll

Gets the element from which OffsetRectangle is calculated.

public:
 property System::Windows::Forms::HtmlElement ^ OffsetParent { System::Windows::Forms::HtmlElement ^ get(); };
public System.Windows.Forms.HtmlElement OffsetParent { get; }
public System.Windows.Forms.HtmlElement? OffsetParent { get; }
member this.OffsetParent : System.Windows.Forms.HtmlElement
Public ReadOnly Property OffsetParent As HtmlElement

Property Value

HtmlElement

The element from which the offsets are calculated.

If an element's parent or another element in the element's hierarchy uses relative or absolute positioning, OffsetParent will be the first relatively or absolutely positioned element in which the current element is nested. If none of the elements above the current element are absolutely or relatively positioned, OffsetParent will be the BODY tag of the document.

Examples

The following code example shows how OffsetParent and OffsetRectangle differ for span1, span2 and span3:

<HTML>  
    <BODY id="documentBody">  

        <DIV id="div1">  
            <SPAN id="span1">Placeholder text 1.</SPAN>  
        </DIV>  

        <DIV id="div2" style="position:relative;top:100px;left:100px;">  
            <SPAN id="span2">Placeholder text 2.</SPAN>  
        </DIV>  

        <DIV id="div3" style="position:absolute;top:200px;left:200px;">  
            <DIV id="div4" style="position:relative;top:100px;left:100px;">  
                <SPAN id="span3">Placeholder text 3.</SPAN>  
            </DIV>  
        </DIV>  

    </BODY>  
</HTML>  

private void GetOffsets()
{
    String str = "";
    HtmlDocument doc = webBrowser1.Document;

    foreach (HtmlElement elem in doc.GetElementsByTagName("SPAN"))
    {
        str += "OffsetParent for " + elem.Id + " is " + elem.OffsetParent.Id;
        str += "; OffsetRectangle is " + elem.OffsetRectangle.ToString() + "\n";
    }

    MessageBox.Show(str);
}

Private Sub GetOffsets()
    Dim Str As String = ""
    Dim Doc As HtmlDocument = WebBrowser1.Document

    For Each Elem As HtmlElement In Doc.GetElementsByTagName("SPAN")
        Str &= "OffsetParent for " & Elem.Id & " is " & Elem.OffsetParent.Id
        Str &= "; OffsetRectangle is " & Elem.OffsetRectangle.ToString() & vbCrLf
    Next

    MessageBox.Show(Str)
End Sub

Remarks

Elements can be positioned on an HTML page in one of three ways: default flow positioning; relative positioning, in which the element is offset by a fixed amount relative to its parent; and absolute positioning, in which the element is given a fixed coordinate position relative to the upper-left corner of the document.

When a document's elements use relative or absolute positioning, you can use OffsetParent to calculate an element's coordinate position in the client area.

For more information about element positioning in HTML, see About Element Positioning.

Applies to

See also