ImageMapEventArgs 类

参考

定义

命名空间:: System.Web.UI.WebControls

程序集:: System.Web.dll

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

为 Click 控件的 ImageMap 事件提供数据。

public ref class ImageMapEventArgs : EventArgs

public class ImageMapEventArgs : EventArgs

type ImageMapEventArgs = class
    inherit EventArgs

Public Class ImageMapEventArgs
Inherits EventArgs

继承: Object

EventArgs
ImageMapEventArgs

示例

下面的代码示例演示如何为 Click 事件创建事件处理程序。控件 ImageMap 包含两个 RectangleHotSpot 对象。属性 ImageMap.HotSpotMode 设置为 HotSpotMode.PostBack，这会导致每次用户单击其中一个 RectangleHotSpot 对象时，页面都会发回服务器。事件 Click 由 VoteMap_Clicked 事件处理程序处理。检查VoteMap_ClickedPostBackValue在数据中发送的 ImageMapEventArgs 属性，以确定哪个RectangleHotSpot对象与事件相关联。若要使此示例正常工作，必须为属性提供自己的映像 ImageUrl ，并相应地更新映像的路径，以便应用程序能够找到它。

<%@ 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>

注解

单击Click控件中的 ImageMap 对象时HotSpot，将引发事件。若要允许 HotSpot 对象引发 Click 事件，必须先将 ImageMap.HotSpotMode 属性或 HotSpot.HotSpotMode 属性设置为 HotSpotMode.PostBack。若要以编程方式控制单击回发 HotSpot 时执行的操作，请为 Click 事件提供事件处理程序。

属性 PostBackValue 存储一个字符串，该字符串与单击时对象的行为 HotSpot 相关联。单击时HotSpot，ImageMapEventArgs此字符串在事件数据中传递。

构造函数

ImageMapEventArgs(String)

初始化 ImageMapEventArgs 类的新实例。

属性

PostBackValue

获取 String，它分配给单击的 PostBackValue 对象的 HotSpot 属性。

方法

Equals(Object)	确定指定对象是否等于当前对象。 (继承自 Object)
GetHashCode()	作为默认哈希函数。 (继承自 Object)
GetType()	获取当前实例的 Type。 (继承自 Object)
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
ToString()	返回表示当前对象的字符串。 (继承自 Object)

适用于

通过

ImageMapEventArgs 类

定义

示例

注解

构造函数

属性

方法

适用于

另请参阅

其他资源