ImageMapEventHandler Delegat

Definicja

Reprezentuje metodę, która obsługuje Click zdarzenie ImageMap formantu.Represents the method that handles the Click event of an ImageMap control.

public delegate void ImageMapEventHandler(System::Object ^ sender, ImageMapEventArgs ^ e);
public delegate void ImageMapEventHandler(object sender, ImageMapEventArgs e);
type ImageMapEventHandler = delegate of obj * ImageMapEventArgs -> unit
Public Delegate Sub ImageMapEventHandler(sender As Object, e As ImageMapEventArgs)

Parametry

sender
Object

Źródło zdarzenia.The source of the event.

e
ImageMapEventArgs

Argument typu ImageMapEventArgs , który zawiera dane zdarzenia.The argument of type ImageMapEventArgs that contains the event data.

Dziedziczenie
ImageMapEventHandler

Przykłady

Poniższy przykład kodu demonstruje, jak utworzyć procedurę obsługi zdarzeń dla Click zdarzenia.The following code example demonstrates how to create an event handler for the Click event. ImageMapKontrolka zawiera dwa RectangleHotSpot obiekty.The ImageMap control contains two RectangleHotSpot objects. ImageMap.HotSpotModeWłaściwość jest ustawiona na HotSpotMode.PostBack , która powoduje, że strona jest ogłaszana z powrotem na serwerze za każdym razem, gdy użytkownik kliknie jeden z RectangleHotSpot obiektów.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. ClickZdarzenie jest obsługiwane przez VoteMap_Clicked program obsługi zdarzeń.The Click event is handled by the VoteMap_Clicked event handler. Aby ten przykład działał prawidłowo, należy podać własny obraz ImageUrl właściwości i odpowiednio zaktualizować ścieżkę do obrazu, aby aplikacja mogła go zlokalizować.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="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>
<%@ 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 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>

Uwagi

Podczas tworzenia ImageMapEventHandler delegata identyfikuje się metodę, która obsługuje zdarzenie.When you create an ImageMapEventHandler delegate, you identify the method that handles the event. Aby skojarzyć zdarzenie z programem obsługi zdarzeń, Dodaj wystąpienie delegata do zdarzenia.To associate the event with your event handler, add an instance of the delegate to the event. Program obsługi zdarzeń jest wywoływany przy każdym wystąpieniu zdarzenia, o ile nie usunięto delegata.The event handler is called whenever the event occurs, unless you remove the delegate. Aby uzyskać więcej informacji na temat delegatów obsługi zdarzeń, zobacz temat Obsługa iwywoływanie zdarzeń.For more information about event handler delegates, see Handling and Raising Events.

Metody rozszerzania

GetMethodInfo(Delegate)

Pobiera obiekt, który reprezentuje metodę reprezentowaną przez określony delegat.Gets an object that represents the method represented by the specified delegate.

Dotyczy

Zobacz też