C# 在N层、域驱动设计、MVC应用程序中处理异常
我构建了一个MVC应用程序，如下所示：C# 在N层、域驱动设计、MVC应用程序中处理异常,c#,exception-handling,domain-driven-design,C#,Exception Handling,Domain Driven Design,我构建了一个MVC应用程序，如下所示： MVC应用程序-应用程序层-业务层-存储库-数据 我阅读了应用程序的代码，发现似乎没有人以类似于数据传递的方式传递异常 换句话说，数据通过接口引用，并在不同的上下文中重用。如果数据层发生异常，如何将其发送到GUI或相关层？应该使用接口吗？应用程序中处理异常的结构是什么？我没有阅读链接的文档，但我有一个简单的例子，在这个例子中，我提出异常以响应无法满足不变量的情况。假设我正在创建一个实例，但由于某种原因它是“无效的”，比如说用户输入错误。与其让我的实体处于无
MVC应用程序-应用程序层-业务层-存储库-数据换句话说，数据通过接口引用，并在不同的上下文中重用。如果数据层发生异常，如何将其发送到GUI或相关层？应该使用接口吗？应用程序中处理异常的结构是什么？我没有阅读链接的文档，但我有一个简单的例子，在这个例子中，我提出异常以响应无法满足不变量的情况。假设我正在创建一个实例，但由于某种原因它是“无效的”，比如说用户输入错误。与其让我的实体处于无效状态（在DDD中是no-no）并让系统“验证”它，不如在创建它时抛出一个异常。相关的“验证消息”（针对用户）是从未满足的同一规范实例中提取的，并且我的派生异常包含UI需要的值 不变量异常的示例：
public class InvariantException : MyAppException
{
public object FailingObject = null;
public ModelStateDictionary ModelState = new ModelStateDictionary();
public InvariantException() { }
public InvariantException(object failingObject, ModelStateDictionary messages)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
public InvariantException(object failingObject, ModelStateDictionary messages,
Exception innerException)
: base("refer to ModelState", innerException)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
}
public class PostFieldLengthSpecification : ISpecification<Post>
{
private const string TITLE_LENGTH_RANGE = "5-100";
private const string BODY_LENGTH_RANGE = "20-10000";
public bool IsSatisfiedBy(Post post)
{
return this.GetErrors(post).IsValid;
}
public ModelStateDictionary GetErrors(Post post)
{
ModelStateDictionary modelState = new ModelStateDictionary();
if (!post.Title.Trim().Length.Within(TITLE_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.Title),
"Please make sure the title is between {0} characters in length".With(TITLE_LENGTH_RANGE));
if (!post.BodyMarkup.Trim().Length.Within(BODY_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.BodyMarkup),
"Please make sure the post is between {0} characters in length".With(BODY_LENGTH_RANGE));
return modelState;
}
}
public static Post GetNewPost(string title, string bodyMarkup, DateTime posted)
{
var post = new Post(0, title, bodyMarkup, posted, new List<Comment>());
var fieldLengthSpec = new PostFieldLengthSpecification();
if (fieldLengthSpec.IsSatisfiedBy(post))
return post;
else
throw new InvariantException(post, fieldLengthSpec.GetErrors(post));
}
public class PostModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
if (bindingContext.ModelType == typeof(Post))
{
try
{
// Create Post
return base.BindModel(controllerContext, bindingContext);
}
catch (InvariantException ie)
{
// If invalid, add errors from factory to ModelState
bindingContext.ModelState.AddNewErrors(ie.ModelState);
bindingContext.ModelState.AddValuesFor<Post>(bindingContext.ValueProvider);
return ie.FailingObject;
}
}
public class InvariantException : MyAppException
{
public object FailingObject = null;
public ModelStateDictionary ModelState = new ModelStateDictionary();
public InvariantException() { }
public InvariantException(object failingObject, ModelStateDictionary messages)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
public InvariantException(object failingObject, ModelStateDictionary messages,
Exception innerException)
: base("refer to ModelState", innerException)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
}
public class PostFieldLengthSpecification : ISpecification<Post>
{
private const string TITLE_LENGTH_RANGE = "5-100";
private const string BODY_LENGTH_RANGE = "20-10000";
public bool IsSatisfiedBy(Post post)
{
return this.GetErrors(post).IsValid;
}
public ModelStateDictionary GetErrors(Post post)
{
ModelStateDictionary modelState = new ModelStateDictionary();
if (!post.Title.Trim().Length.Within(TITLE_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.Title),
"Please make sure the title is between {0} characters in length".With(TITLE_LENGTH_RANGE));
if (!post.BodyMarkup.Trim().Length.Within(BODY_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.BodyMarkup),
"Please make sure the post is between {0} characters in length".With(BODY_LENGTH_RANGE));
return modelState;
}
}
public static Post GetNewPost(string title, string bodyMarkup, DateTime posted)
{
var post = new Post(0, title, bodyMarkup, posted, new List<Comment>());
var fieldLengthSpec = new PostFieldLengthSpecification();
if (fieldLengthSpec.IsSatisfiedBy(post))
return post;
else
throw new InvariantException(post, fieldLengthSpec.GetErrors(post));
}
public class PostModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
if (bindingContext.ModelType == typeof(Post))
{
try
{
// Create Post
return base.BindModel(controllerContext, bindingContext);
}
catch (InvariantException ie)
{
// If invalid, add errors from factory to ModelState
bindingContext.ModelState.AddNewErrors(ie.ModelState);
bindingContext.ModelState.AddValuesFor<Post>(bindingContext.ValueProvider);
return ie.FailingObject;
}
}
公共类PostFieldLength规范：I规范
{
私有常量字符串标题\u长度\u范围=“5-100”；
私有常量字符串正文\u长度\u范围=“20-10000”；
公共图书馆（邮政）满意
{
返回此.GetErrors（post）.IsValid；
}
公共ModelStateDictionary GetErrors（Post Post）
{
ModelStateDictionary modelState=新的ModelStateDictionary（）；
如果（！post.Title.Trim（）.Length.在（Title\u Length\u范围内））
modelState.AddModelError（StongTypeHelpers.GetPropertyName（（Post p）=>p.Title），
“请确保标题长度在{0}个字符之间”。使用（title_length_RANGE））；
如果（！post.BodyMarkup.Trim（）.Length.在（BODY\u Length\u范围内））
modelState.AddModelError（StongTypeHelpers.GetPropertyName（（Post p）=>p.BodyMarkup），
“请确保帖子长度在{0}个字符之间”。使用（BODY_length_RANGE））；
返回模型状态；
}
}
public class InvariantException : MyAppException
{
public object FailingObject = null;
public ModelStateDictionary ModelState = new ModelStateDictionary();
public InvariantException() { }
public InvariantException(object failingObject, ModelStateDictionary messages)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
public InvariantException(object failingObject, ModelStateDictionary messages,
Exception innerException)
: base("refer to ModelState", innerException)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
}
public class PostFieldLengthSpecification : ISpecification<Post>
{
private const string TITLE_LENGTH_RANGE = "5-100";
private const string BODY_LENGTH_RANGE = "20-10000";
public bool IsSatisfiedBy(Post post)
{
return this.GetErrors(post).IsValid;
}
public ModelStateDictionary GetErrors(Post post)
{
ModelStateDictionary modelState = new ModelStateDictionary();
if (!post.Title.Trim().Length.Within(TITLE_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.Title),
"Please make sure the title is between {0} characters in length".With(TITLE_LENGTH_RANGE));
if (!post.BodyMarkup.Trim().Length.Within(BODY_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.BodyMarkup),
"Please make sure the post is between {0} characters in length".With(BODY_LENGTH_RANGE));
return modelState;
}
}
public static Post GetNewPost(string title, string bodyMarkup, DateTime posted)
{
var post = new Post(0, title, bodyMarkup, posted, new List<Comment>());
var fieldLengthSpec = new PostFieldLengthSpecification();
if (fieldLengthSpec.IsSatisfiedBy(post))
return post;
else
throw new InvariantException(post, fieldLengthSpec.GetErrors(post));
}
public class PostModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
if (bindingContext.ModelType == typeof(Post))
{
try
{
// Create Post
return base.BindModel(controllerContext, bindingContext);
}
catch (InvariantException ie)
{
// If invalid, add errors from factory to ModelState
bindingContext.ModelState.AddNewErrors(ie.ModelState);
bindingContext.ModelState.AddValuesFor<Post>(bindingContext.ValueProvider);
return ie.FailingObject;
}
}
publicstaticpost-GetNewPost（字符串标题、字符串bodyMarkup、DateTime-Post）
{
var post=new post（0，title，bodyMarkup，posted，new List（））；
var fieldLengthSpec=新的PostFieldLengthSpecification（）；
if（现场长度规格符合（post））
回程站；
其他的
抛出新的不变量异常（post，fieldLengthSpec.GetErrors（post））；
}
public class InvariantException : MyAppException
{
public object FailingObject = null;
public ModelStateDictionary ModelState = new ModelStateDictionary();
public InvariantException() { }
public InvariantException(object failingObject, ModelStateDictionary messages)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
public InvariantException(object failingObject, ModelStateDictionary messages,
Exception innerException)
: base("refer to ModelState", innerException)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
}
public class PostFieldLengthSpecification : ISpecification<Post>
{
private const string TITLE_LENGTH_RANGE = "5-100";
private const string BODY_LENGTH_RANGE = "20-10000";
public bool IsSatisfiedBy(Post post)
{
return this.GetErrors(post).IsValid;
}
public ModelStateDictionary GetErrors(Post post)
{
ModelStateDictionary modelState = new ModelStateDictionary();
if (!post.Title.Trim().Length.Within(TITLE_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.Title),
"Please make sure the title is between {0} characters in length".With(TITLE_LENGTH_RANGE));
if (!post.BodyMarkup.Trim().Length.Within(BODY_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.BodyMarkup),
"Please make sure the post is between {0} characters in length".With(BODY_LENGTH_RANGE));
return modelState;
}
}
public static Post GetNewPost(string title, string bodyMarkup, DateTime posted)
{
var post = new Post(0, title, bodyMarkup, posted, new List<Comment>());
var fieldLengthSpec = new PostFieldLengthSpecification();
if (fieldLengthSpec.IsSatisfiedBy(post))
return post;
else
throw new InvariantException(post, fieldLengthSpec.GetErrors(post));
}
public class PostModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
if (bindingContext.ModelType == typeof(Post))
{
try
{
// Create Post
return base.BindModel(controllerContext, bindingContext);
}
catch (InvariantException ie)
{
// If invalid, add errors from factory to ModelState
bindingContext.ModelState.AddNewErrors(ie.ModelState);
bindingContext.ModelState.AddValuesFor<Post>(bindingContext.ValueProvider);
return ie.FailingObject;
}
}
公共类PostModelBinder:DefaultModelBinder
{
公共重写对象BindModel（ControllerContext ControllerContext，ModelBindingContext bindingContext）
{
if（bindingContext.ModelType==typeof（Post））
{
尝试
{
//创建帖子
返回base.BindModel（controllerContext、bindingContext）；
}
捕获（不变量异常）
{
//如果无效，请将错误从factory添加到ModelState
bindingContext.ModelState.AddNewErrors（即ModelState）；
bindingContext.ModelState.AddValuesFor（bindingContext.ValueProvider）；
返回ie.FailingObject；
}
}
希望这能有所帮助。我还没有阅读链接的文档，但我有一个简单的例子，在这个例子中，我提出了异常，以响应无法满足不变量的情况。假设我正在创建一个实例，它由于某种原因是“无效”的，让我们假设用户输入错误。与其让我的实体处于无效状态（在DDD中是“否”），不如让系统“验证”它，它在创建时抛出异常。相关的“验证消息”（针对用户）是从未满足的同一规范实例中提取的，并且我的派生异常包含UI需要的值 不变量异常的示例：
public class InvariantException : MyAppException
{
public object FailingObject = null;
public ModelStateDictionary ModelState = new ModelStateDictionary();
public InvariantException() { }
public InvariantException(object failingObject, ModelStateDictionary messages)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
public InvariantException(object failingObject, ModelStateDictionary messages,
Exception innerException)
: base("refer to ModelState", innerException)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
}
public class PostFieldLengthSpecification : ISpecification<Post>
{
private const string TITLE_LENGTH_RANGE = "5-100";
private const string BODY_LENGTH_RANGE = "20-10000";
public bool IsSatisfiedBy(Post post)
{
return this.GetErrors(post).IsValid;
}
public ModelStateDictionary GetErrors(Post post)
{
ModelStateDictionary modelState = new ModelStateDictionary();
if (!post.Title.Trim().Length.Within(TITLE_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.Title),
"Please make sure the title is between {0} characters in length".With(TITLE_LENGTH_RANGE));
if (!post.BodyMarkup.Trim().Length.Within(BODY_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.BodyMarkup),
"Please make sure the post is between {0} characters in length".With(BODY_LENGTH_RANGE));
return modelState;
}
}
public static Post GetNewPost(string title, string bodyMarkup, DateTime posted)
{
var post = new Post(0, title, bodyMarkup, posted, new List<Comment>());
var fieldLengthSpec = new PostFieldLengthSpecification();
if (fieldLengthSpec.IsSatisfiedBy(post))
return post;
else
throw new InvariantException(post, fieldLengthSpec.GetErrors(post));
}
public class PostModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
if (bindingContext.ModelType == typeof(Post))
{
try
{
// Create Post
return base.BindModel(controllerContext, bindingContext);
}
catch (InvariantException ie)
{
// If invalid, add errors from factory to ModelState
bindingContext.ModelState.AddNewErrors(ie.ModelState);
bindingContext.ModelState.AddValuesFor<Post>(bindingContext.ValueProvider);
return ie.FailingObject;
}
}
public class InvariantException : MyAppException
{
public object FailingObject = null;
public ModelStateDictionary ModelState = new ModelStateDictionary();
public InvariantException() { }
public InvariantException(object failingObject, ModelStateDictionary messages)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
public InvariantException(object failingObject, ModelStateDictionary messages,
Exception innerException)
: base("refer to ModelState", innerException)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
}
public class PostFieldLengthSpecification : ISpecification<Post>
{
private const string TITLE_LENGTH_RANGE = "5-100";
private const string BODY_LENGTH_RANGE = "20-10000";
public bool IsSatisfiedBy(Post post)
{
return this.GetErrors(post).IsValid;
}
public ModelStateDictionary GetErrors(Post post)
{
ModelStateDictionary modelState = new ModelStateDictionary();
if (!post.Title.Trim().Length.Within(TITLE_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.Title),
"Please make sure the title is between {0} characters in length".With(TITLE_LENGTH_RANGE));
if (!post.BodyMarkup.Trim().Length.Within(BODY_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.BodyMarkup),
"Please make sure the post is between {0} characters in length".With(BODY_LENGTH_RANGE));
return modelState;
}
}
public static Post GetNewPost(string title, string bodyMarkup, DateTime posted)
{
var post = new Post(0, title, bodyMarkup, posted, new List<Comment>());
var fieldLengthSpec = new PostFieldLengthSpecification();
if (fieldLengthSpec.IsSatisfiedBy(post))
return post;
else
throw new InvariantException(post, fieldLengthSpec.GetErrors(post));
}
public class PostModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
if (bindingContext.ModelType == typeof(Post))
{
try
{
// Create Post
return base.BindModel(controllerContext, bindingContext);
}
catch (InvariantException ie)
{
// If invalid, add errors from factory to ModelState
bindingContext.ModelState.AddNewErrors(ie.ModelState);
bindingContext.ModelState.AddValuesFor<Post>(bindingContext.ValueProvider);
return ie.FailingObject;
}
}
公共类PostFieldLength规范：I规范
{
私有常量字符串标题\u长度\u范围=“5-100”；
私有常量字符串正文\u长度\u范围=“20-10000”；
公共图书馆（邮政）满意
{
返回此.GetErrors（post）.IsValid；
}
公共ModelStateDictionary GetErrors（Post Post）
{
ModelStateDictionary modelState=新的ModelStateDictionary（）；
如果（！post.Title.Trim（）.Length.在（Title\u Length\u范围内））
modelState.AddModelError（StongTypeHelpers.GetPropertyName（（Post p）=>p.Title），
“请确保标题长度在{0}个字符之间”。使用（title_length_RANGE））；
如果（！post.BodyMarkup.Trim（）.Length.在（BODY\u Length\u范围内））
modelState.AddModelError（StongTypeHelpers.GetPropertyName（（Post p）=>p.BodyMarkup），
“请确保帖子长度在{0}个字符之间”。使用（BODY_length_RANGE））；
返回模型状态；
}
}
public class InvariantException : MyAppException
{
public object FailingObject = null;
public ModelStateDictionary ModelState = new ModelStateDictionary();
public InvariantException() { }
public InvariantException(object failingObject, ModelStateDictionary messages)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
public InvariantException(object failingObject, ModelStateDictionary messages,
Exception innerException)
: base("refer to ModelState", innerException)
{
this.FailingObject = failingObject;
this.ModelState = messages;
}
}
public class PostFieldLengthSpecification : ISpecification<Post>
{
private const string TITLE_LENGTH_RANGE = "5-100";
private const string BODY_LENGTH_RANGE = "20-10000";
public bool IsSatisfiedBy(Post post)
{
return this.GetErrors(post).IsValid;
}
public ModelStateDictionary GetErrors(Post post)
{
ModelStateDictionary modelState = new ModelStateDictionary();
if (!post.Title.Trim().Length.Within(TITLE_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.Title),
"Please make sure the title is between {0} characters in length".With(TITLE_LENGTH_RANGE));
if (!post.BodyMarkup.Trim().Length.Within(BODY_LENGTH_RANGE))
modelState.AddModelError(StongTypeHelpers.GetPropertyName((Post p) => p.BodyMarkup),
"Please make sure the post is between {0} characters in length".With(BODY_LENGTH_RANGE));
return modelState;
}
}
public static Post GetNewPost(string title, string bodyMarkup, DateTime posted)
{
var post = new Post(0, title, bodyMarkup, posted, new List<Comment>());
var fieldLengthSpec = new PostFieldLengthSpecification();
if (fieldLengthSpec.IsSatisfiedBy(post))
return post;
else
throw new InvariantException(post, fieldLengthSpec.GetErrors(post));
}
public class PostModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
if (bindingContext.ModelType == typeof(Post))
{
try
{
// Create Post
return base.BindModel(controllerContext, bindingContext);
}
catch (InvariantException ie)
{
// If invalid, add errors from factory to ModelState
bindingContext.ModelState.AddNewErrors(ie.ModelState);
bindingContext.ModelState.AddValuesFor<Post>(bindingContext.ValueProvider);
return ie.FailingObject;
}
}
publicstaticpost-GetNewPost（字符串标题、字符串bodyMarkup、DateTime-Post）
{
var post=new post（0，title，bodyMarkup，posted，new List）（）