Adds the specified error message to the errors collection for the model-state dictionary that is associated with the specified key.
Namespace:  System.Web.Http.ModelBinding
Assembly:  System.Web.Http (in System.Web.Http.dll)
Syntax
'Declaration
Public Sub AddModelError ( _
    key As String, _
    errorMessage As String _
)
'Usage
Dim instance As ModelStateDictionary
Dim key As String
Dim errorMessage As String
instance.AddModelError(key, errorMessage)
public void AddModelError(
    string key,
    string errorMessage
)
public:
void AddModelError(
    String^ key, 
    String^ errorMessage
)
member AddModelError : 
        key:string * 
        errorMessage:string -> unit 
public function AddModelError(
    key : String, 
    errorMessage : String
)
Parameters
- key
 Type: System.String
 The key.
- errorMessage
 Type: System.String
 The error message.