MVC Razor need to get Substring

You could implement in view as follows:

@Html.DisplayFor(modelItem => modelItem.FirstName).ToString().Substring(0,5)

You should put a property on your ViewModel for that instead of trying to get it in the view code. The views only responsibility is to display what is given to it by the model, it shouldn't be creating new data from the model.

You can use a custom extension method as shown below:

/// <summary>
/// Returns only the first n characters of a String.
/// </summary>
/// <param name="str"></param>
/// <param name="start"></param>
/// <param name="maxLength"></param>
/// <returns></returns>
public static string TruncateString(this string str, int start, int maxLength)
{        
    return str.Substring(start, Math.Min(str.Length, maxLength));
}

Hope this helps...

Might I suggest that the view is not the right place to do this. You should probably have a separate model property, FirstInitial, that contains the logic. Your view should simply display this.

  public class Person
  {
       public string FirstName { get; set; }

       public string FirstInitial
       {
           get { return FirstName != null ? FirstName.Substring(0,1) : ""; }
       }

       ...
   }


   @Html.DisplayFor( modelItem => modelItem.FirstInitial )