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RectangleHotSpot Class

.NET Framework 4.5

Defines a rectangular hot spot region in an ImageMap control. This class cannot be inherited.

System.Object
  System.Web.UI.WebControls.HotSpot
    System.Web.UI.WebControls.RectangleHotSpot

Namespace:  System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)
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public sealed class RectangleHotSpot : HotSpot

The RectangleHotSpot type exposes the following members.

  NameDescription
Public methodRectangleHotSpotInitializes a new instance of the RectangleHotSpot class.
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  NameDescription
Public propertyAccessKeyGets or sets the access key that allows you to quickly navigate to the HotSpot region. (Inherited from HotSpot.)
Public propertyAlternateTextGets or sets the alternate text to display for a HotSpot object in an ImageMap control when the image is unavailable or renders to a browser that does not support images. (Inherited from HotSpot.)
Public propertyBottomGets or sets the y-coordinate of the bottom side of the rectangular region defined by this RectangleHotSpot object.
Public propertyHotSpotModeGets or sets the behavior of a HotSpot object in an ImageMap control when the HotSpot is clicked. (Inherited from HotSpot.)
Public propertyLeftGets or sets the x-coordinate of the left side of the rectangular region defined by this RectangleHotSpot object.
Protected propertyMarkupNameWhen overridden in a derived class, gets the string representation for the HotSpot object's shape. (Inherited from HotSpot.)
Public propertyNavigateUrlGets or sets the URL to navigate to when a HotSpot object is clicked. (Inherited from HotSpot.)
Public propertyPostBackValueGets or sets the name of the HotSpot object to pass in the event data when the HotSpot is clicked. (Inherited from HotSpot.)
Public propertyRightGets or sets the x-coordinate of the right side of the rectangular region defined by this RectangleHotSpot object.
Public propertyTabIndexGets or sets the tab index of the HotSpot region. (Inherited from HotSpot.)
Public propertyTargetGets or sets the target window or frame in which to display the Web page content linked to when a HotSpot object that navigates to a URL is clicked. (Inherited from HotSpot.)
Public propertyTopGets or sets the y-coordinate of the top side of the rectangular region defined by this RectangleHotSpot object.
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  NameDescription
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Public methodGetCoordinatesReturns a string that represents the x -and y-coordinates of a RectangleHotSpot object's top left corner and the x- and y-coordinates of its bottom right corner. (Overrides HotSpot.GetCoordinates().)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodToStringReturns the String representation of this instance of a HotSpot object. (Inherited from HotSpot.)
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  NameDescription
Explicit interface implemetationPrivate propertyIStateManager.IsTrackingViewStateInfrastructure. Gets a value indicating whether the HotSpot object is tracking its view-state changes. (Inherited from HotSpot.)
Explicit interface implemetationPrivate methodIStateManager.LoadViewStateInfrastructure. Restores the HotSpot object's previously saved view state to the object. (Inherited from HotSpot.)
Explicit interface implemetationPrivate methodIStateManager.SaveViewStateInfrastructure. Saves the changes to the HotSpot object's view state since the last time the page was posted back to the server. (Inherited from HotSpot.)
Explicit interface implemetationPrivate methodIStateManager.TrackViewStateInfrastructure. Instructs the HotSpot region to track changes to its view state. (Inherited from HotSpot.)
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This class defines a rectangular hot spot region in an ImageMap control. To define the region of the RectangleHotSpot object, set the Left property to the value that represents the x-coordinate of the rectangular region's top left corner. Set the Top property to the value that represents the y-coordinate of the rectangular region's top left corner. Set the Right property to the value that represents the x-coordinate of the rectangular region's bottom right corner. Set of the Bottom property to the value that represents the y-coordinate of the rectangular region's bottom right corner.

When a RectangleHotSpot control is clicked, the page navigates to a URL, generates a post back to the server, or does nothing. The HotSpotMode property specifies this behavior. To navigate to a URL, set the HotSpotMode property to HotSpotMode.Navigate and use the NavigateUrl property to specify the URL to navigate to. To post back to the server, set the HotSpotMode property to HotSpotMode.PostBack and use the PostBackValue property to specify a name for the RectangleHotSpot object. This name will be passed in the ImageMapEventArgs event data when the RectangleHotSpot is clicked. . If you want the HotSpot object to have no behavior, set the HotSpotMode property to HotSpotMode.Inactive.

TopicLocation
How to: Add ImageMap Web Server Controls to a Web Forms PageBuilding ASP .NET Web Applications
How to: Add ImageMap Web Server Controls to a Web Forms PageBuilding ASP .NET Web Applications

The following code example demonstrates how to declaratively create an ImageMap control that contains two RectangleHotSpot objects. The ImageMap.HotSpotMode property is set to HotSpotMode.PostBack, which causes the page to post back to the server each time a user clicks one of the hot spot regions. Each time the user clicks one of the RectangleHotSpot objects, the GetCoordinates method is called and the coordinates of the selected hot spot are displayed to the user. For this example to work correctly, you must supply your own image for the ImageUrl property and update the path to the image appropriately so that the application can locate it.

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

  void VoteMap_Clicked (Object sender, ImageMapEventArgs e)
  {
    string coordinates;
    string hotSpotType;
    int yescount = ((ViewState["yescount"] != null)? (int)ViewState["yescount"] : 0);
    int nocount = ((ViewState["nocount"] != null)? (int)ViewState["nocount"] : 0);

    // When a user clicks the "Yes" hot spot,
    // display the hot spot's name and coordinates.
    if (e.PostBackValue.Contains("Yes"))
    {
      yescount += 1;
      coordinates = Vote.HotSpots[0].GetCoordinates();
      hotSpotType = Vote.HotSpots[0].ToString ();
      Message1.Text = "You selected " + hotSpotType + " " + e.PostBackValue + ".<br />" +
                      "The coordinates are " + coordinates + ".<br />" +
                      "The current vote count is " + yescount.ToString() + 
            " yes votes and " + nocount.ToString() + " no votes.";
    }

    // When a user clicks the "No" hot spot,
    // display the hot spot's name and coordinates.
    else if (e.PostBackValue.Contains("No"))
    {
      nocount += 1;
      coordinates = Vote.HotSpots[1].GetCoordinates();
      hotSpotType = Vote.HotSpots[1].ToString ();
      Message1.Text = "You selected " + hotSpotType + " " + e.PostBackValue + ".<br />" +
                      "The coordinates are " + coordinates + ".<br />" +
            "The current vote count is " + yescount.ToString() +
            " yes votes and " + nocount.ToString() + " no votes.";
    }

    else
    {
      Message1.Text = "You did not click a valid hot spot region.";
    }

    ViewState["yescount"] = yescount;
    ViewState["nocount"] = nocount;
  }           

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="head1" runat="server">
  <title>ImageMap Class Post Back Example</title>
</head>
  <body>
    <form id="form1" runat="server">

      <h3>ImageMap Class Post Back Example</h3>

      <asp:imagemap id="Vote"           
        imageurl="Images/VoteImage.jpg"
        width="400" 
        height="200" 
        alternatetext="Vote Yes or No"
        hotspotmode="PostBack"
        onclick="VoteMap_Clicked"
        runat="Server">            

        <asp:RectangleHotSpot          
          top="0"
          left="0"
          bottom="200"
          right="200"
          postbackvalue="Yes"
          alternatetext="Vote yes">
        </asp:RectangleHotSpot>

        <asp:RectangleHotSpot 
          top="0"
          left="201"
          bottom="200"
          right="400"
          postbackvalue="No"
          alternatetext="Vote no">
        </asp:RectangleHotSpot>

      </asp:imagemap>

      <br /><br />

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

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

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0

Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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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