问题
I want to get all the error messages out of the modelState without knowing the key values. Looping through to grab all the error messages that the ModelState contains.
How can I do this?
回答1:
foreach (ModelState modelState in ViewData.ModelState.Values) {
foreach (ModelError error in modelState.Errors) {
DoSomethingWith(error);
}
}
See also How do I get the collection of Model State Errors in ASP.NET MVC?.
回答2:
Using LINQ:
IEnumerable<ModelError> allErrors = ModelState.Values.SelectMany(v => v.Errors);
回答3:
Building on the LINQ verison, if you want to join all the error messages into one string:
string messages = string.Join("; ", ModelState.Values
.SelectMany(x => x.Errors)
.Select(x => x.ErrorMessage));
回答4:
I was able to do this using a little LINQ,
public static List<string> GetErrorListFromModelState
(ModelStateDictionary modelState)
{
var query = from state in modelState.Values
from error in state.Errors
select error.ErrorMessage;
var errorList = query.ToList();
return errorList;
}
The above method returns a list of validation errors.
Further Reading :
How to read all errors from ModelState in ASP.NET MVC
回答5:
During debugging I find it useful to put a table at the bottom of each of my pages to show all ModelState errors.
<table class="model-state">
@foreach (var item in ViewContext.ViewData.ModelState)
{
if (item.Value.Errors.Any())
{
<tr>
<td><b>@item.Key</b></td>
<td>@((item.Value == null || item.Value.Value == null) ? "<null>" : item.Value.Value.RawValue)</td>
<td>@(string.Join("; ", item.Value.Errors.Select(x => x.ErrorMessage)))</td>
</tr>
}
}
</table>
<style>
table.model-state
{
border-color: #600;
border-width: 0 0 1px 1px;
border-style: solid;
border-collapse: collapse;
font-size: .8em;
font-family: arial;
}
table.model-state td
{
border-color: #600;
border-width: 1px 1px 0 0;
border-style: solid;
margin: 0;
padding: .25em .75em;
background-color: #FFC;
}
</style>
回答6:
As I discovered having followed the advice in the answers given so far, you can get exceptions occuring without error messages being set, so to catch all problems you really need to get both the ErrorMessage and the Exception.
String messages = String.Join(Environment.NewLine, ModelState.Values.SelectMany(v => v.Errors)
.Select( v => v.ErrorMessage + " " + v.Exception));
or as an extension method
public static IEnumerable<String> GetErrors(this ModelStateDictionary modelState)
{
return modelState.Values.SelectMany(v => v.Errors)
.Select( v => v.ErrorMessage + " " + v.Exception).ToList();
}
回答7:
In case anyone wants to return the Name of the Model property for binding the error message in a strongly typed view.
List<ErrorResult> Errors = new List<ErrorResult>();
foreach (KeyValuePair<string, ModelState> modelStateDD in ViewData.ModelState)
{
string key = modelStateDD.Key;
ModelState modelState = modelStateDD.Value;
foreach (ModelError error in modelState.Errors)
{
ErrorResult er = new ErrorResult();
er.ErrorMessage = error.ErrorMessage;
er.Field = key;
Errors.Add(er);
}
}
This way you can actually tie the error in with the field that threw the error.
回答8:
For just in case someone need it i made and use the following static class in my projects
Usage example:
if (!ModelState.IsValid)
{
var errors = ModelState.GetModelErrors();
return Json(new { errors });
}
Usings:
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.Mvc;
using WebGrease.Css.Extensions;
Class:
public static class ModelStateErrorHandler
{
/// <summary>
/// Returns a Key/Value pair with all the errors in the model
/// according to the data annotation properties.
/// </summary>
/// <param name="errDictionary"></param>
/// <returns>
/// Key: Name of the property
/// Value: The error message returned from data annotation
/// </returns>
public static Dictionary<string, string> GetModelErrors(this ModelStateDictionary errDictionary)
{
var errors = new Dictionary<string, string>();
errDictionary.Where(k => k.Value.Errors.Count > 0).ForEach(i =>
{
var er = string.Join(", ", i.Value.Errors.Select(e => e.ErrorMessage).ToArray());
errors.Add(i.Key, er);
});
return errors;
}
public static string StringifyModelErrors(this ModelStateDictionary errDictionary)
{
var errorsBuilder = new StringBuilder();
var errors = errDictionary.GetModelErrors();
errors.ForEach(key => errorsBuilder.AppendFormat("{0}: {1} -", key.Key,key.Value));
return errorsBuilder.ToString();
}
}
回答9:
Outputting just the Error messages themselves wasn't sufficient for me, but this did the trick.
var modelQuery = (from kvp in ModelState
let field = kvp.Key
let state = kvp.Value
where state.Errors.Count > 0
let val = state.Value?.AttemptedValue ?? "[NULL]"
let errors = string.Join(";", state.Errors.Select(err => err.ErrorMessage))
select string.Format("{0}:[{1}] (ERRORS: {2})", field, val, errors));
Trace.WriteLine(string.Join(Environment.NewLine, modelQuery));
回答10:
And this works too:
var query = from state in ModelState.Values
from error in state.Errors
select error.ErrorMessage;
var errors = query.ToArray(); // ToList() and so on...
回答11:
This is expanding upon the answer from @Dunc . See xml doc comments
// ReSharper disable CheckNamespace
using System.Linq;
using System.Web.Mvc;
public static class Debugg
{
/// <summary>
/// This class is for debugging ModelState errors either in the quick watch
/// window or the immediate window.
/// When the model state contains dozens and dozens of properties,
/// it is impossible to inspect why a model state is invalid.
/// This method will pull up the errors
/// </summary>
/// <param name="modelState">modelState</param>
/// <returns></returns>
public static ModelError[] It(ModelStateDictionary modelState)
{
var errors = modelState.Values.SelectMany(x => x.Errors).ToArray();
return errors;
}
}
回答12:
Useful for passing array of error messages to View, perhaps via Json:
messageArray = this.ViewData.ModelState.Values.SelectMany(modelState => modelState.Errors, (modelState, error) => error.ErrorMessage).ToArray();
回答13:
In addition, ModelState.Values.ErrorMessage may be empty, but ModelState.Values.Exception.Message may indicate an error.
回答14:
In your implementation you are missing static Class, this should be.
if (!ModelState.IsValid)
{
var errors = ModelStateErrorHandler.GetModelErrors(this.ModelState);
return Json(new { errors });
}
rather
if (!ModelState.IsValid)
{
var errors = ModelState.GetModelErrors();
return Json(new { errors });
}
回答15:
I dont know that is the problem in my case, sometimes I get message in ErrorMessage Section of ModelState and sometimes in the Exception Message of the ModelState error.
Hence I have Created a method that can deal with both the scenarios.. Hope this helps everyone here..
public static string GetErrorMessageFromModelState(ModelStateDictionary modelState)
{
string errorMessage = string.Empty;
try
{
string[] errorMessageList = (from m in modelState
where m.Value.Errors.Count > 0
select string.Join(", ", m.Value.Errors.Select(x =>
!string.IsNullOrEmpty(x.ErrorMessage) ? x.ErrorMessage : !string.IsNullOrEmpty(x.Exception.Message) ?
x.Exception.Message.Split('\'').Length > 0 ? x.Exception.Message.Split('\'')[1].ToString() : m.Key.Split('.').Length > 1 ?
m.Key.Split('.')[1] : m.Key.Split('.')[0] : m.Key.Split('.')[0]))).ToArray();
errorMessage = string.Format("Error in Field(s): " + string.Join(", ", errorMessageList) + " {0} required.", (errorMessageList.Count() > 1 ? "are" : "is"));
}
catch (Exception ex)
{
errorMessage = ex.Message;
if (ex.InnerException != null)
errorMessage += Environment.NewLine + ex.InnerException;
}
return errorMessage;
}
来源：https://stackoverflow.com/questions/1352948/how-to-get-all-errors-from-asp-net-mvc-modelstate