CODEWITHSUNDEEP
c#asp.netasp.net-mvcrazorasp.net-mvc-5
Unbreakable
Unbreakable

Reputation: 8084

When to use @using in my razor syntax view in ASP.Net MVC 5

And yes, I searched it on google I could not find the exact answer.

So, When to use @using SomeModel in my razor syntax view. I am new to ASP.net MVC 5 and I know that each view can be strongly bound to a model or a viewModel and we use @model ModelName. What will be the situation when I will have to use @using in my razor view. Any example would be highly appreciated.

Upvotes: 7

Views: 7107

Answers (3)

Willy David Jr
Willy David Jr

Reputation: 9131

Aside from the answers above, you would typically use @using on creating form:

@using (Html.BeginForm("Upload", "Upload", FormMethod.Post, 
                                  new { enctype = "multipart/form-data" }))
{
//TODO: Logic here
}

This provides convenient syntax that ensures the correct use of IDisposable objects. For more reference you can visit here.

Upvotes: 3

Federico Dipuma
Federico Dipuma

Reputation: 18265

Every time you need to import a namespace inside your view. This is the same as when you import a namespace in a standard C# code file.

So, if you need to use a type which is declared in a different namespace than the View one, you'll need to add a using statement before using that type.

@using OtherNamespace

@{
    var example = new ExampleClass(); // full name is OtherNamespace.ExampleClass
}

Be aware that there is another method for importing namespaces inside Views in MVC 5, which uses the Web.config file located in "Views" folder (note that this is not the global Web.config file). You may add further namespaces by adding the following parts:

<system.web.webPages.razor>
    <pages pageBaseType="System.Web.Mvc.WebViewPage">
        <namespaces>
            <add namespace="System.Web.Mvc" />
            <add namespace="OtherNamespace" />
        </namespaces>
    </pages>
</system.web.webPages.razor>

This way you will not need to add a @using statement inside the .cshtml file.

[Edit]

Regarding the @model statement inside a view, there are essentially two options:

@using MyNamespace.MyNestedNamespace
@model MyModel

Or, if you think you will not need any other types from that namespace:

@model MyNamespace.MyNestedNamespace.MyModel

There is no real difference, is up to you what you think is better for that view.

Upvotes: 8

User3250
User3250

Reputation: 3423

Many situations where you would need @using, for e.g. see below:

You have a function the view

@using System.Text.RegularExpressions;
 public string StripHtml(string inputHTML)
 {
    if (inputHTML == null) {
        return string.Empty;
    }
    string noHTML = Regex.Replace(inputHTML, @"<[^>]+>|&nbsp;", "").Trim();
    string noHTMLNormalised = Regex.Replace(noHTML, @"\s{2,}", " ");
    return noHTMLNormalised;
}

Here my func need Regex from System.Text.RegularExpressions;

Pass some new model class to another view

@using Model.Customer
@model Model.User

var cust = new Customer();
cust.Name = Model.Name;
Html.RenderPartial("_CustomerDetails", cust);

Hope, it made some sense.

Upvotes: 1

Related Questions