Is it possible to get Dictionary from query string?

问题

My controller method looks like this:

public ActionResult SomeMethod(Dictionary<int, string> model)
{

}

Is it possible to call this method and populate "model" using only query string? I mean, typing something like this:

ControllerName/SomeMethod?model.0=someText&model.1=someOtherText

in our browser address bar. Is it possible?

EDIT:

It would appear my question was misunderstood - I want to bind the query string, so that the Dictionary method parameter is populated automatically. In other words - I don't want to manually create the dictionary inside my method, but have some automathic .NET binder do it form me, so I can access it right away like this:

public ActionResult SomeMethod(Dictionary<int, string> model)
{
    var a = model[SomeKey];
}

Is there an automatic binder, smart enough to do this?

回答1:

In ASP.NET Core, you can use the following syntax (without needing a custom binder):

?dictionaryVariableName[KEY]=VALUE

Assuming you had this as your method:

public ActionResult SomeMethod([FromQuery] Dictionary<int, string> model)

And then called the following URL:

?model[0]=firstString&model[1]=secondString

Your dictionary would then be automatically populated. With values:

(0, "firstString")
(1, "secondString")

回答2:

For .NET Core 2.1, you can do this very easily.

public class SomeController : ControllerBase
{
    public IActionResult Method([FromQuery]IDictionary<int, string> query)
    {
        // Do something
    }
}

And the url

/Some/Method?1=value1&2=value2&3=value3

It will bind that to the dictionary. You don't even have to use the parameter name query.

回答3:

try custom model binder

      public class QueryStringToDictionaryBinder: IModelBinder
{
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        var collection = controllerContext.HttpContext.Request.QueryString;
        var modelKeys =
            collection.AllKeys.Where(
                m => m.StartsWith(bindingContext.ModelName));
        var dictionary = new Dictionary<int, string>();

        foreach (string key in modelKeys)
        {
            var splits = key.Split(new[]{'.'}, StringSplitOptions.RemoveEmptyEntries);
            int nummericKey = -1;
            if(splits.Count() > 1)
            {
                var tempKey = splits[1]; 
                if(int.TryParse(tempKey, out nummericKey))
                {
                    dictionary.Add(nummericKey, collection[key]);    
                }   
            }                 
        }

        return dictionary;
    }
}

in controller action use it on model

     public ActionResult SomeMethod(
        [ModelBinder(typeof(QueryStringToDictionaryBinder))]
        Dictionary<int, string> model)
    {

        //return Content("Test");
    }

回答4:

More specific to mvc model binding is to construct the query string as

/somemethod?model[0].Key=1&model[0].Value=One&model[1].Key=2&model[1].Value=Two

Custom Binder would simply follow DefaultModelBinder

   public class QueryStringToDictionary<TKey, TValue> : IModelBinder
{
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        var modelBindingContext = new ModelBindingContext
        {

            ModelName = bindingContext.ModelName,
            ModelMetadata = new ModelMetadata(new EmptyModelMetadataProvider(), null, 
                null, typeof(Dictionary<TKey, TValue>), bindingContext.ModelName),
            ValueProvider = new QueryStringValueProvider(controllerContext)
        };

        var temp = new DefaultModelBinder().BindModel(controllerContext, modelBindingContext);

        return temp;
    }
}

Apply custom model binder in model as

     public ActionResult SomeMethod(
        [ModelBinder(typeof(QueryStringToDictionary<int, string>))] Dictionary<int, string> model)
    {
       // var a = model[SomeKey];
        return Content("Test");
    }

来源：https://stackoverflow.com/questions/22707788/is-it-possible-to-get-dictionary-from-query-string