.NET Framework Class Library ImageMapEventHandler Delegate Represents the method that handles the Click event of an ImageMap control. (in System.Web.dll)
Syntax
Public Delegate Sub ImageMapEventHandler ( _
sender As Object, _
e As ImageMapEventArgs _
)
public delegate void ImageMapEventHandler(
Object sender,
ImageMapEventArgs e
)
public delegate void ImageMapEventHandler(
Object^ sender,
ImageMapEventArgs^ e
)
type ImageMapEventHandler =
delegate of
sender:Object *
e:ImageMapEventArgs -> unit
Remarks
When you create an ImageMapEventHandler delegate, you identify the method that handles the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see Events and Delegates.
Examples
The following code example demonstrates how to create an event handler for the Click event. The ImageMap control 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 RectangleHotSpot objects. The Click event is handled by the VoteMap_Clicked event handler. 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.
<%@ 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 VoteMap_Clicked(ByVal sender As Object, ByVal e As ImageMapEventArgs)
Dim coordinates As String
Dim hotSpotType As String
Dim yescount As Integer
Dim nocount As Integer
If (ViewState("yescount") IsNot Nothing) Then
yescount = Convert.ToInt32(ViewState("yescount"))
Else
yescount = 0
End If
If (ViewState("nocount") IsNot Nothing) Then
nocount = Convert.ToInt32(ViewState("nocount"))
Else
nocount = 0
End If
' When a user clicks the "Yes" hot spot,
' display the hot spot's name and coordinates.
If (e.PostBackValue.Contains("Yes")) Then
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.
ElseIf (e.PostBackValue.Contains("No")) Then
nocount += 1
coordinates = Vote.HotSpots.Item(1).GetCoordinates()
hotSpotType = Vote.HotSpots.Item(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."
End If
ViewState("yescount") = yescount
ViewState("nocount") = nocount
End Sub
</script>
<html >
<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>
<%@ 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 >
<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>
Version Information
.NET FrameworkSupported in: 4, 3.5, 3.0, 2.0
Platforms
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role not supported), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
See Also
|
Bibliothèque de classes .NET Framework ImageMapEventHandler, délégué Représente la méthode qui gère l'événement Click d'un contrôle ImageMap. (dans System.Web.dll)
Syntaxe
Public Delegate Sub ImageMapEventHandler ( _
sender As Object, _
e As ImageMapEventArgs _
)
public delegate void ImageMapEventHandler(
Object sender,
ImageMapEventArgs e
)
public delegate void ImageMapEventHandler(
Object^ sender,
ImageMapEventArgs^ e
)
type ImageMapEventHandler =
delegate of
sender:Object *
e:ImageMapEventArgs -> unit
Notes
Lorsque vous créez un délégué ImageMapEventHandler, vous spécifiez la méthode qui gérera l'événement. Pour associer l'événement à votre gestionnaire d'événements, ajoutez une instance du délégué à l'événement. Le gestionnaire d'événements est appelé à chaque fois que l'événement se produit, sauf si vous supprimez le délégué. Pour plus d'informations sur les délégués de gestionnaires d'événements, consultez Événements et délégués.
Exemples
L'exemple de code suivant montre comment créer un gestionnaire d'événements pour l'événement Click. Le contrôle ImageMap contient deux objets RectangleHotSpot. La propriété ImageMap..::.HotSpotMode a la valeur HotSpotMode.PostBack, ce qui a pour effet de publier la page sur le serveur chaque fois qu'un utilisateur clique sur l'un des objets RectangleHotSpot. L'événement Click est géré par le gestionnaire d'événements VoteMap_Clicked. Pour que cet exemple fonctionne correctement, vous devez fournir votre propre image pour la propriété ImageUrl et mettre à jour le chemin d'accès à l'image de façon à ce que l'application puisse la localiser.
<%@ 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 VoteMap_Clicked(ByVal sender As Object, ByVal e As ImageMapEventArgs)
Dim coordinates As String
Dim hotSpotType As String
Dim yescount As Integer
Dim nocount As Integer
If (ViewState("yescount") IsNot Nothing) Then
yescount = Convert.ToInt32(ViewState("yescount"))
Else
yescount = 0
End If
If (ViewState("nocount") IsNot Nothing) Then
nocount = Convert.ToInt32(ViewState("nocount"))
Else
nocount = 0
End If
' When a user clicks the "Yes" hot spot,
' display the hot spot's name and coordinates.
If (e.PostBackValue.Contains("Yes")) Then
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.
ElseIf (e.PostBackValue.Contains("No")) Then
nocount += 1
coordinates = Vote.HotSpots.Item(1).GetCoordinates()
hotSpotType = Vote.HotSpots.Item(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."
End If
ViewState("yescount") = yescount
ViewState("nocount") = nocount
End Sub
</script>
<html >
<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>
<%@ 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 >
<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>
Informations de version
.NET FrameworkPris en charge dans : 4, 3.5, 3.0, 2.0
Plateformes
Windows 7, Windows Vista SP1 ou ultérieur, Windows XP SP3, Windows XP SP2 Édition x64, Windows Server 2008 (installation minimale non prise en charge), Windows Server 2008 R2 (installation minimale prise en charge avec SP1 ou version ultérieure), Windows Server 2003 SP2
Le .NET Framework ne prend pas en charge toutes les versions de chaque plateforme. Pour obtenir la liste des versions prises en charge, consultez Configuration requise du .NET Framework.
Voir aussi
RéférenceAutres ressources
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