How to create a readonly textbox in ASP.NET MVC3 Razor

@Html.TextBoxFor(m => m.userCode, new { @readonly="readonly" })

You are welcome to make an HTML Helper for this, but this is simply just an HTML attribute like any other. Would you make an HTML Helper for a text box that has other attributes?

UPDATE: Now it's very simple to add HTML attributes to the default editor templates. It neans instead of doing this:

@Html.TextBoxFor(m => m.userCode, new { @readonly="readonly" })

you simply can do this:

@Html.EditorFor(m => m.userCode, new { htmlAttributes = new { @readonly="readonly" } })

Benefits: You haven't to call .TextBoxFor, etc. for templates. Just call .EditorFor.

While @Shark's solution works correctly, and it is simple and useful, my solution (that I use always) is this one: Create an editor-template that can handles readonly attribute:

1. Create a folder named EditorTemplates in ~/Views/Shared/
2. Create a razor PartialView named String.cshtml

3. Fill the String.cshtml with this code:

   @if(ViewData.ModelMetadata.IsReadOnly) {
       @Html.TextBox("", ViewData.TemplateInfo.FormattedModelValue,
           new { @class = "text-box single-line readonly", @readonly = "readonly", disabled = "disabled" })
   } else {
       @Html.TextBox("", ViewData.TemplateInfo.FormattedModelValue,
           new { @class = "text-box single-line" })
   }
   

4. In model class, put the [ReadOnly(true)] attribute on properties which you want to be readonly.

For example,

public class Model {
    // [your-annotations-here]
    public string EditablePropertyExample { get; set; }

    // [your-annotations-here]
    [ReadOnly(true)]
    public string ReadOnlyPropertyExample { get; set; }
}

Now you can use Razor's default syntax simply:

@Html.EditorFor(m => m.EditablePropertyExample)
@Html.EditorFor(m => m.ReadOnlyPropertyExample)

The first one renders a normal text-box like this:

<input class="text-box single-line" id="field-id" name="field-name" />

And the second will render to;

<input readonly="readonly" disabled="disabled" class="text-box single-line readonly" id="field-id" name="field-name" />

You can use this solution for any type of data (DateTime, DateTimeOffset, DataType.Text, DataType.MultilineText and so on). Just create an editor-template.

The solution with TextBoxFor is OK, but if you don't want to see the field like EditBox stylish (it might be a little confusing for the user) involve changes as follows:

1. Razor code before changes

   <div class="editor-field">
        @Html.EditorFor(model => model.Text)
        @Html.ValidationMessageFor(model => model.Text)
   </div>
   

2. After changes

   <!-- New div display-field (after div editor-label) -->
   <div class="display-field">
       @Html.DisplayFor(model => model.Text)
   </div>
   
   <div class="editor-field">
       <!-- change to HiddenFor in existing div editor-field -->
       @Html.HiddenFor(model => model.Text)
       @Html.ValidationMessageFor(model => model.Text)
   </div>
   

Generally, this solution prevents field from editing, but shows value of it. There is no need for code-behind modifications.

With credits to the previous answer by @Bronek and @Shimmy:

This is like I have done the same thing in ASP.NET Core:

<input asp-for="DisabledField" disabled="disabled" />
<input asp-for="DisabledField" class="hidden" />

The first input is readonly and the second one passes the value to the controller and is hidden. I hope it will be useful for someone working with ASP.NET Core.