<!--自定义异常配置-->
<settingException>
 <exceptions>
  <!--add优先级高于group-->
  <add exception="Exceptions.PasswordErrorException"
     view ="PasswordErrorView"
     handler="ExceptionHandlers.PasswordErrorExceptionHandler"/>
  <groups>
   <!--group可以配置一种异常的view和handler-->
   <group view="EmptyErrorView" handler="ExceptionHandlers.EmptyExceptionHandler">
    <add exception="Exceptions.UserNameEmptyException"/>
    <add exception="Exceptions.EmailEmptyException"/>
   </group>    
  </groups>
 </exceptions>
</settingException>

public class ExceptionConfig
{
  /// <summary>
  /// 视图
  /// </summary>
  public string View{get;set;}
 
  /// <summary>
  /// 异常对象
  /// </summary>
  public Exception Exception{get;set;}
 
  /// <summary>
  /// 异常处理程序
  /// </summary>
  public IExceptionHandler Handler{get;set;}
}

public interface IExceptionHandler
{
  /// <summary>
  /// 异常是否处理完成
  /// </summary>
  bool HasHandled{get;set;}
 
  /// <summary>
  /// 处理异常
  /// </summary>
  /// <param name="ex"></param>
  void Handle(Exception ex);
}

public class SettingHandleErrorFilter : IExceptionFilter
{
  public void OnException(ExceptionContext filterContext)
  {
    if(filterContext == null)
    {
      throw new ArgumentNullException("filterContext");
    }
    ExceptionConfig config = SettingExceptionProvider.Container[filterContext.Exception.GetType()];
    if(config == null)
    {
      return;
    }
    if(config.Handler != null)
    {
      //执行Handle方法        
      config.Handler.Handle(filterContext.Exception);
      if (config.Handler.HasHandled)
      {
        //异常已处理，不需要后续操作
        filterContext.ExceptionHandled = true;
        return;
      }
    }      
    //否则，如果有定制页面，则显示
    if(!string.IsNullOrEmpty(config.View))
    {
      //这里还可以扩展成实现IView的视图
      ViewResult view = new ViewResult();
      view.ViewName = config.View;
      filterContext.Result = view;
      filterContext.ExceptionHandled = true;
      return;
    }
    //否则将异常继续传递
  }
}

public class SettingExceptionProvider
{
  public static Dictionary<Type, ExceptionConfig> Container =
    new Dictionary<Type, ExceptionConfig>();
 
  static SettingExceptionProvider()
  {
    InitContainer();
  }
 
  //读取配置信息，初始化容器
  private static void InitContainer()
  {
    var section = WebConfigurationManager.GetSection("settingException") as SettingExceptionSection;
    if(section == null)
    {
      return;
    }
    InitFromGroups(section.Exceptions.Groups);
    InitFromAddCollection(section.Exceptions.AddCollection);
  }
 
  private static void InitFromGroups(GroupCollection groups)
  {           
    foreach (var group in groups.Cast<GroupElement>())
    { 
      ExceptionConfig config = new ExceptionConfig();
      config.View = group.View;
      config.Handler = CreateHandler(group.Handler);
      foreach(var item in group.AddCollection.Cast<AddElement>())
      {
        Exception ex = CreateException(item.Exception);
        config.Exception = ex;
        Container[ex.GetType()] = config;
      }
    }
  }
 
  private static void InitFromAddCollection(AddCollection collection)
  {
    foreach(var item in collection.Cast<AddElement>())
    {
      ExceptionConfig config = new ExceptionConfig();
      config.View = item.View;
      config.Handler = CreateHandler(item.Handler);
      config.Exception = CreateException(item.Exception);
      Container[config.Exception.GetType()] = config;
    }
  }
 
  //根据完全限定名创建IExceptionHandler对象
  private static IExceptionHandler CreateHandler(string fullName)      
  {
    if(string.IsNullOrEmpty(fullName))
    {
      return null;
    }
    Type type = Type.GetType(fullName);
    return Activator.CreateInstance(type) as IExceptionHandler;
  }
 
  //根据完全限定名创建Exception对象
  private static Exception CreateException(string fullName)
  {
    if(string.IsNullOrEmpty(fullName))
    {
      return null;
    }
    Type type = Type.GetType(fullName);
    return Activator.CreateInstance(type) as Exception;
  }
}

/// <summary>
/// settingExceptions节点
/// </summary>
public class SettingExceptionSection : ConfigurationSection
{
  [ConfigurationProperty("exceptions",IsRequired=true)]
  public ExceptionsElement Exceptions
  {
    get
    {
      return (ExceptionsElement)base["exceptions"];
    }
  }
}

/// <summary>
/// exceptions节点
/// </summary>
public class ExceptionsElement : ConfigurationElement
{
  private static readonly ConfigurationProperty _addProperty =
    new ConfigurationProperty("", typeof(AddCollection), null, ConfigurationPropertyOptions.IsDefaultCollection);
 
  [ConfigurationProperty("", IsDefaultCollection = true)]
  public AddCollection AddCollection
  {
    get
    {
      return (AddCollection)base[_addProperty];
    }
  }
 
  [ConfigurationProperty("groups")]
  public GroupCollection Groups
  {
    get
    {
      return (GroupCollection)base["groups"];
    }
  }
}

/// <summary>
/// group节点集
/// </summary>
[ConfigurationCollection(typeof(GroupElement),AddItemName="group")]
public class GroupCollection : ConfigurationElementCollection
{   
  /*override*/
 
  protected override ConfigurationElement CreateNewElement()
  {
    return new GroupElement();
  }
 
  protected override object GetElementKey(ConfigurationElement element)
  {
    return element;
  }
}

/// <summary>
/// group节点
/// </summary>
public class GroupElement : ConfigurationElement
{
  private static readonly ConfigurationProperty _addProperty =
    new ConfigurationProperty("", typeof(AddCollection), null, ConfigurationPropertyOptions.IsDefaultCollection);
 
  [ConfigurationProperty("view")]
  public string View
  {
    get
    {
      return base["view"].ToString();
    }
  }
 
  [ConfigurationProperty("handler")]
  public string Handler
  {
    get
    {
      return base["handler"].ToString();
    }
  }
 
  [ConfigurationProperty("", IsDefaultCollection = true)]
  public AddCollection AddCollection
  {
    get
    {
      return (AddCollection)base[_addProperty];
    }
  }    
}

/// <summary>
/// add节点集
/// </summary>  
public class AddCollection : ConfigurationElementCollection
{     
  /*override*/
 
  protected override ConfigurationElement CreateNewElement()
  {
    return new AddElement();
  }
 
  protected override object GetElementKey(ConfigurationElement element)
  {
    return element;
  }
}

/// <summary>
/// add节点
/// </summary>
public class AddElement : ConfigurationElement
{
  [ConfigurationProperty("view")]
  public string View
  {
    get
    {
      return base["view"] as string;
    }
  }
 
  [ConfigurationProperty("handler")]
  public string Handler
  {
    get
    {
      return base["handler"] as string;
    }
  }
 
  [ConfigurationProperty("exception", IsRequired = true)]
  public string Exception
  {
    get
    {
      return base["exception"] as string;
    }
  }
}

public class PasswordErrorException : Exception{}
public class UserNameEmptyException : Exception{}
public class EmailEmptyException : Exception{}

public class PasswordErrorExceptionHandler : IExceptionHandler
{
  public bool HasHandled{get;set;}
   
  public void Handle(Exception ex)
  {
    //具体处理逻辑...
  }
}
 
public class EmptyExceptionHandler : IExceptionHandler
{
  public bool HasHandled { get; set; }
 
  public void Handle(Exception ex)
  {
    //具体处理逻辑...
  }
}

public ActionResult Index()
{
  throw new PasswordErrorException();
}
public ActionResult Index2()
{
  throw new UserNameEmptyException();
}
public ActionResult Index3()
{
  throw new EmailEmptyException();
}