类、结构或接口成员声明中的标记“尝试”无效答案

【问题标题】：Invalid token 'try' in class, struct, or interface member declaration类、结构或接口成员声明中的标记“尝试”无效
【发布时间】：2014-02-02 22:33:36
【问题描述】：

今天早上刚开始使用 ASPX 文件，但遇到了障碍。

我收到以下错误：

Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. 

Compiler Error Message: CS1519: Invalid token 'try' in class, struct, or interface member declaration

Source Error:

Line 5:  int portno = 52791;
Line 6:  IPAddress ipa = Dns.GetHostEntry(hostname).AddressList[0];
Line 7:  try
Line 8:  {
Line 9:      System.Net.Sockets.Socket sock = new System.Net.Sockets.Socket(System.Net.Sockets.AddressFamily.InterNetwork, System.Net.Sockets.SocketType.Stream, System.Net.Sockets.ProtocolType.Tcp);

Source File: c:\inetpub\wwwroot\test.aspx    Line: 7

来自以下 ASPX 文件代码：

<%@ Page Language="C#" %>
<%@ Import namespace="System" %>
<script runat="server">
string hostname = "localhost";
int portno = 52791;
IPAddress ipa = Dns.GetHostEntry(hostname).AddressList[0];
try
{
    System.Net.Sockets.Socket sock = new System.Net.Sockets.Socket(System.Net.Sockets.AddressFamily.InterNetwork, System.Net.Sockets.SocketType.Stream, System.Net.Sockets.ProtocolType.Tcp);
    sock.Connect(ipa, portno);
    if (sock.Connected == true)  // Port is in use and connection is successful
            string output = "Port is Closed";
    sock.Close();

}
catch (System.Net.Sockets.SocketException ex)
{
    if (ex.ErrorCode == 10061)  // Port is unused and could not establish connection 
        string output = "Port is Open!";
    else
        string output = ex.Message;
}
</script>
<html>...

谷歌搜索数小时没有解决我的问题。

【问题讨论】：

可能你忘了把这些东西包装在一个方法中？
简单的答案是不要在标记中这样做；这是属于后面代码的东西，你的错误会很明显。
另外，你在各种范围内重复定义字符串output，它永远无法使用。这实际上是一个编译器错误，除了荒谬之外。
基于this answer，似乎假设您的脚本是Javascript而不是C#，否则您需要明确告知它。
对于内联代码，使用<% 和%> 而不是<script runat="server"> 和</script>。

标签： c# asp.net try-catch

【解决方案1】：

<%@ Page Language="C#"  Debug="true" %>
<%@ Import namespace="System.Net" %>
<script runat="server">
public class Whatever
{
public static string output()
{
string hostname = "localhost";
int portno = 52791;
//IPAddress ipa = Dns.GetHostEntry(hostname).AddressList[0];
byte[] ipb = {192,168,1,30};
IPAddress ipa = new IPAddress(ipb);
string ret = "";
try
{
    System.Net.Sockets.Socket sock = new System.Net.Sockets.Socket(System.Net.Sockets.AddressFamily.InterNetwork, System.Net.Sockets.SocketType.Stream, System.Net.Sockets.ProtocolType.Tcp);
    sock.Connect(ipa, portno);
    if (sock.Connected == true)  // Port is in use and connection is successful
            ret = "Port is Closed";
    sock.Close();

}
catch (System.Net.Sockets.SocketException ex)
{
    if (ex.ErrorCode == 10061)  // Port is unused and could not establish connection 
        ret = "Port is Open!";
    else
        ret = ex.Message;
}
return ret;
}
}
</script>

【讨论】：