我是ASP.NET Core的初学者,只是关于ObjectResult的一个问题。我看到这样的代码:
public override void OnException(ExceptionContext context)
{
var myerror = new
{
Success = false,
Errors = new [] { context.Exception.Message }
};
context.Result = new ObjectResult(myerror)
{
StatusCode = 500
};
context.ExceptionHandled = true;
...
}
我的问题是:
1-是属性'错误'匿名类型的对象“myerror”创建带有异常消息的响应主体?
var myerror = new
{
mySuccess = false,
myErrors = new [] { context.Exception.Message }
};
好吗?
context.ExceptionHandled = true;
的目的是什么?该书说,将异常标记为防止它从MvcMiddleware传播出来。但为什么它需要阻止它传播出去?1)是的。
2)是的,没关系。您可以创建所需结构的对象,而不仅仅是匿名对象。
public class ErrorModel
{
public string Error { get; set; }
public int Id { get; set; }
public List<int> Values { get; set; }
}
//filter
var error = new ErrorModel
{
Error = context.Exception.Message,
Id = 1,
Values = new List<int> { 1, 2, 3 }
};
context.Result = new ObjectResult(error)
{
StatusCode = 500
};
3)您的应用程序中可能存在多个异常过滤器,如果在处理异常时未将ExceptionHandled
设置为true
,则会调用每个过滤器并覆盖Result
。此属性的目的是指示某个筛选器能够处理异常,并且不需要运行其他异常筛选器。当过滤器只能处理某些类型的异常时,它非常有用。
//handles only exceptions caused by dividing by zero
public class DivideByZeroExceptionFilterAttribute : Attribute, IExceptionFilter
{
public void OnException(ExceptionContext context)
{
//chech if this is divide by zero exception
if (!(context.Exception is DivideByZeroException))
return;
var myerror = new
{
result = false,
message = "Division by zero went wrong"
};
context.Result = new ObjectResult(myerror)
{
StatusCode = 500
};
//set "handled" to true since exception is already property handled
//and there is no need to run other filters
context.ExceptionHandled = true;
}
}