在学习ASP.NET的过程中,总是遇到不懂的地方,每次到网上查了之后,总会想过后能再温习下,为了方便自己温习,也为了能让大家一起分享,我将网上找到的一些资料帖到博客上。
首先,我将转载一些ASP.NET的类介绍。
1、按钮的command事件涉及到的类和属性。
         ①、 CommandEventArgs 类为 Command 事件提供数据。
命名空间:System.Web.UI.WebControls
程序集:System.Web(在 system.web.dll 中)
Visual Basic(声明)
Public Class CommandEventArgs
    Inherits EventArgs
Visual Basic(用法)
Dim instance As CommandEventArgs
C#
public class CommandEventArgs : EventArgs
C++
public ref class CommandEventArgs : public EventArgs
J#
public class CommandEventArgs extends EventArgs
JScript
public class CommandEventArgs extends EventArgs
 备注 
当单击 ButtonImageButton 控件时,会引发 Command 事件。
CommandEventArgs 对象包含有关可以在事件处理程序中访问的 Command 事件的数据。使用在 CommandEventArgs 类中可用的属性,可以确定要执行的命令的名称,例如 Sort;还可以确定对该命令加以补充的可选参数,例如 Ascending
示例
下面的示例展示如何访问 CommandEventArgs 中的属性以确定要执行的命令。此示例使用 Button 控件的 OnClick 属性,以声明方式指定事件处理程序。
C#代码:
<%@ Page Language="C#" AutoEventWireup="True" %>
<html>
<head>
   <script runat="server">
      void CommandBtn_Click(Object sender, CommandEventArgs e)
      {
         switch(e.CommandName)
         {
            case "Sort":
               // Call the method to sort the list.
               Sort_List((String)e.CommandArgument);
               break;
            case "Submit":
               // Display a message for the Submit button being clicked.
               Message.Text = "You clicked the Submit button";
               // Test whether the command argument is an empty string ("").
               if((String)e.CommandArgument == "")
               {
                  // End the message.
                  Message.Text += ".";
               }
               else
               {
                  // Display an error message for the command argument.
                  Message.Text += ", however the command argument is not recogized.";
               }               
               break;
            default:
               // The command name is not recognized. Display an error message.
               Message.Text = "Command name not recogized.";
               break;
         }
      }
      void Sort_List(string commandArgument)
      {
 
         switch(commandArgument)
         {
 
            case "Ascending":
 
               // Insert code to sort the list in ascending order here.
               Message.Text = "You clicked the Sort Ascending button.";
               break;
 
            case "Descending":
             
               // Insert code to sort the list in descending order here.
               Message.Text = "You clicked the Sort Descending button.";
               break;
 
            default:
       
               // The command argument is not recognized. Display an error message.
               Message.Text = "Command argument not recogized.";
               break;
 
         }
      }
   </script>
</head>
 
<body>
 
   <form runat="server">
      <h3>Button CommandName Example</h3>
      Click on one of the command buttons.
      <br><br>
 
      <asp:Button id="Button1"
           Text="Sort Ascending"
           CommandName="Sort"
           CommandArgument="Ascending"
           OnCommand="CommandBtn_Click"
           runat="server"/>
 
      &nbsp;
      <asp:Button id="Button2"
           Text="Sort Descending"
           CommandName="Sort"
           CommandArgument="Descending"
           OnCommand="CommandBtn_Click"
           runat="server"/>
 
      <br><br>
      <asp:Button id="Button3"
           Text="Submit"
           CommandName="Submit"
           OnCommand="CommandBtn_Click"
           runat="server"/>
 
      &nbsp;
      <asp:Button id="Button4"
           Text="Unknown Command Name"
           CommandName="UnknownName"
           CommandArgument="UnknownArgument"
           OnCommand="CommandBtn_Click"
           runat="server"/>
 
      &nbsp;
      <asp:Button id="Button5"
           Text="Submit Unknown Command Argument"
           CommandName="Submit"
           CommandArgument="UnknownArgument"
           OnCommand="CommandBtn_Click"
           runat="server"/>
      
      <br><br>
 
      <asp:Label id="Message" runat="server"/>
 
   </form>
 </body>
</html>
 
②、CommandEventArgs.CommandArgument 属性
获取命令的参数。
命名空间:System.Web.UI.WebControls
程序集:System.Web(在 system.web.dll 中)
CommandArgument 可以包含由程序员设置的任何字符串。CommandArgument 属性通过允许您为该命令提供任何附加信息,对 CommandName 属性加以补充。例如,可以将 CommandName 属性设置为 Sort 并将 CommandArgument 属性设置为 Ascending,以指定按升序排序的命令。
 
③、CommandEventArgs.CommandName 属性
获取命令的名称。
命名空间:System.Web.UI.WebControls
程序集:System.Web(在 system.web.dll 中)
使用 CommandName 属性确定要执行的命令。CommandName 属性可以包含由程序员设置的任何字符串。程序员然后可以在代码中标识该命令名并执行适当的任务。
 
2、图像热区ImageMap涉及到的类和属性。
                
                    ①、ImageMapEventArgs 类,ImageMap 控件的 Click 事件提供数据。
命名空间:  System.Web.UI.WebControls
程序集:  System.Web(在 System.Web.dll 中)
                示例
              <%@ page language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "[url]http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd[/url]">
<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>
 
 
      ②、ImageMapEventArgs.PostBackValue 属性 ,获取 String,它分配给单击的 HotSpot 对象的 PostBackValue 属性。
命名空间:  System.Web.UI.WebControls
程序集:  System.Web(在 System.Web.dll 中)
使用该属性以编程方式访问单击的 ImageMap 控件中 HotSpot 对象的 PostBackValue 属性。