using System;

/// <summary>
/// 自定义异常A
/// </summary>
public class MyExceptionA : Exception
{
    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="message"></param>
    public MyExceptionA(string message)
        : base(message)
    { }

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="message"></param>
    /// <param name="ex"></param>
    public MyExceptionA(string message, Exception ex)
        : base(message, ex)
    { }

}

/// <summary>
/// 自定义异常B
/// </summary>
public class MyExceptionB : Exception
{
    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="message"></param>
    public MyExceptionB(string message)
        : base(message)
    { }

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="message"></param>
    /// <param name="ex"></param>
    public MyExceptionB(string message, Exception ex)
        : base(message, ex)
    { }

}

/// <summary>
/// 自定义异常C
/// </summary>
public class MyExceptionC : Exception
{
    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="message"></param>
    public MyExceptionC(string message)
        : base(message)
    { }

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="message"></param>
    /// <param name="ex"></param>
    public MyExceptionC(string message, Exception ex)
        : base(message, ex)
    { }

}

protected void Page_Load(object sender, EventArgs e)
{
    try
    {
        throw new MyExceptionA("发生异常A.");
        //throw new MyExceptionB("发生异常B.");
        //throw new MyExceptionC("发生异常C.");
    }
    catch (MyExceptionA ex)
    {
        Response.Write(ex.Message);
    }
    catch (MyExceptionB ex)
    {
        Response.Write(ex.Message);
    }
    catch (MyExceptionC ex)
    {
        Response.Write(ex.Message);
    }
}