MVC3删除模型状态错误

You can remove model errors by doing something like this:

if (ModelState.ContainsKey("{key}"))
ModelState["{key}"].Errors.Clear();

This builds off previous answers, but simplifies it a little more:

foreach (var modelValue in ModelState.Values)
{
modelValue.Errors.Clear();
}

In general, you don't want to turn off the server-side validation or remove ModelState errors manually. It's doable, but error-prone since it must rely on strings as keys. I upvoted the answer on how to remove the keys, because it is correct and useful, but I recommend against designing yourself into a case where you must strongly consider it.

In your case, you have multiple submit buttons for the same form, but you really aren't submitting the form when you upload the image. To prevent the client-side validation, you can use the "cancel" class as you've already indicated, but I also recommend having the 2nd submit button in a different form, in which case it causes no validation on your main form.

There is a second advantage to using the different form: you can send it to a different ActionResult method which would just handle the logic of uploading the image. This different method would simply not bother to check the "IsValid" property of the model state: it only cares if there is information in the image, and that can be checked separately. (Even if you use the same ActionResult method, you can funnel the logic so that you don't rely on the IsValid property of the model state.)

If you must clear the errors from the model state, and it makes sense to clear all of them, try this:

foreach (var key in ModelState.Keys)
{
ModelState[key].Errors.Clear();
}

This keeps you from depending on getting the key names correct, but preserves the values should any values (valid or invalid) already exist in the model.

One last thing to check for in these cases is whether you have values that are only sometimes in the view, which will not cause client-side validation (they're not in the view), but do result in server-side validation issues. In this case, it's best to use @Html.HiddenFor(model => model.PropertyName, if you can, assuming the value has already been set, it just isn't visible in this view.

I use it sometimes, so I've made an extension method out of it:

public static ModelStateDictionary ClearError(this ModelStateDictionary m, string fieldName)
{
if (m.ContainsKey(fieldName))
m[fieldName].Errors.Clear();
return m;
}

It can be used fluently to clear error for multiple fields.

use ModelState.Remove("{key}") to remove the error from model , which will reset the ModelState.IsValid to true

ModelState.Remove("{key}");

ModelState.ClearValidationState("KeyName");
ModelState.MarkFieldValid("KeyName");

Here's code that loops through all the errors and removes the ones that are NOT in the desired page. I have two pages and I only want to show the errors for the 1st page. (The 2nd page is hidden but will be visible later when page 1 is hidden.) You simply get the errors and loop through and remove the errors that are not in the currently visible page. PageNum is an integer set earlier.

var errors = ModelState.Keys.Where(k => ModelState[k].Errors.Count > 0).Select(k => new { propertyName = k, errorMessage = ModelState[k].Errors[0].ErrorMessage });


bool isError = false;


foreach (var error in errors)
{
isError = CheckForErrors(error.propertyName, pageNum);
ModelState.Remove(error.propertyName);
}


private bool CheckForErrors(string propertyName, int page)
{
var Page1Properties = new Dictionary<string, string>();
Page1Properties.Add("biz_dbaBusinessName", "biz_dbaBusinessName");


var Page2Properties = new Dictionary<string, string>();
Page2Properties.Add("bank_name", "bank_name");


string result;


switch (page)
{
case 1:
return (Page1Properties.TryGetValue(propertyName, out result));
break;
case 2:
return (Page2Properties.TryGetValue(propertyName, out result));
break;
default:
break;
}


return false;
}