PolygonHotSpot Constructor ()

 

Initializes a new instance of the PolygonHotSpot class.

Namespace:   System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

Public Sub New

Use this constructor to initialize a new instance of the PolygonHotSpot class.

The following code example demonstrates how to programmatically create a PolygonHotSpot object and add it to an ImageMap control. The ImageMap control contains two other PolygonHotSpot objects that have been added declaratively. Each PolygonHotSpot object represents a geographical region on the map. When the user clicks a PolygonHotSpot object, it posts back to the server and the type and name of the hot spot are displayed in a label.

<%@ Page Language="VB" %>

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

  Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    ' Programmatically create a PolygonHotSpot.
    Dim Polygon1 As New PolygonHotSpot
    Polygon1.Coordinates = "128,185,335,157,400,224,400,400,228,400"
    Polygon1.PostBackValue = "Southern"
    Polygon1.AlternateText = "Southern Region"

    ' Add it to the end of the ImageMap control's
    ' HotSpotCollection.
    Regions.HotSpots.Add(Polygon1)
  End Sub

  Sub RegionMap_Clicked(ByVal sender As Object, ByVal e As ImageMapEventArgs)
    Dim hotSpotType As String

    ' When a user clicks a hot spot, display
    ' the hot spot's type and name.
    Select Case (e.PostBackValue)

      Case ("Western")
        hotSpotType = Regions.HotSpots(0).ToString()
        Message1.Text = "You selected " & hotSpotType & " " & e.PostBackValue

      Case ("Northern")
        hotSpotType = Regions.HotSpots(1).ToString()
        Message1.Text = "You selected " & hotSpotType & " " & e.PostBackValue

      Case ("Southern")
        hotSpotType = Regions.HotSpots(2).ToString()
        Message1.Text = "You selected " & hotSpotType & " " & e.PostBackValue

      Case Else
        Message1.Text = "You did not click a valid hot spot region."

    End Select
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
  <title>PolygonHotSpot Constructor Example</title>
</head>
  <body>
    <form id="Form1" runat="server">

      <h3>PolygonHotSpot Constructor Example</h3>

      <!-- Change or remove the width and height attributes as
           appropriate for your image. -->
      <asp:imagemap id="Regions"           
        imageurl="Images/RegionMap.jpg"
        alternatetext="Sales regions" 
        hotspotmode="PostBack"
        width="400"
        height="400"
        onclick="RegionMap_Clicked"   
        runat="Server">            

        <asp:PolygonHotSpot 
          coordinates="0,0,176,0,125,182,227,400,0,400"         
          postbackvalue="Western"
          alternatetext="Western Region">
        </asp:PolygonHotSpot>

        <asp:PolygonHotSpot 
          coordinates="177,0,400,0,400,223,335,154,127,180"         
          postbackvalue="Northern"
          alternatetext="Northern Region">
        </asp:PolygonHotSpot>

      </asp:imagemap>

      <br /><br />

      <asp:label id="Message1"
        runat="Server">
      </asp:label>                 

    </form>      
  </body>
</html>

.NET Framework
Available since 2.0
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