Mvc Html.DropDownList on load replace some string

Question

I've have this Dropdown that is generated by my Enum

@Html.DropDownList("MyType",
EnumHelper.GetSelectList(typeof(C_Survey.Models.QuestionType)),
"Select My Type",
new { @class = "form-control N_Q_type" })

Enum:

public enum QuestionType {
    Single_Choice,
    Multiple_Choice,
    Range
}

My question is, how can I replace the _ with a space ?

score 2 · Answer 1 · edited May 23 '17 at 11:54

I don't know much details of GetSelectList method there, but I assumed it receives a System.Enum and returning a SelectList collection like this:

public static SelectList GetSelectList(this Enum enumeration)
{
    var source = Enum.GetValues(enumeration);
    // other stuff
    ...

    return new SelectList(...);
}

There are 2 approaches to solve this issue:

First Approach (Using Custom Attribute)

This approach involves creating a custom attribute to define display name (set attribute target to field or others which fit to entire enum members):

public class DisplayNameAttribute : Attribute
{
    public string DisplayName { get; protected set; }
    public DisplayNameAttribute(string value)
    {
        this.DisplayName = value;
    }

    public string GetName()
    {
        return this.DisplayName;
    }
}

Hence, the enum structure should be modified to this:

public enum QuestionType 
{
    [DisplayName("Single Choice")]
    Single_Choice,

    [DisplayName("Multiple Choice")]
    Multiple_Choice,

    [DisplayName("By Range")]
    Range
}

Later, it is necessary to modify GetSelectList method to accept custom attribute created above which includes DisplayName property:

public static SelectList GetSelectList<T>(this T enumeration)
{
    var source = Enum.GetValues(typeof(T));

    var items = new Dictionary<Object, String>();
    var displaytype = typeof(DisplayNameAttribute);

    foreach (var value in source)
    {
        System.Reflection.FieldInfo field = value.GetType().GetField(value.ToString());
        DisplayNameAttribute attr = (DisplayNameAttribute)field.GetCustomAttributes(displaytype, false).FirstOrDefault();

        items.Add(value, attr != null ? attr.GetName() : value.ToString());
    }

    return new SelectList(items, "Key", "Value");
}

Second Approach (Using Direct Type Cast & Lambda)

Similar to first approach, GetSelectList method will return SelectList from an enum, however instead of using custom attribute this approach uses member names to build select list items as shown below (T is enum type parameter):

public static SelectList GetSelectList<T>(this T enumeration)
{
    var source = Enum.GetValues(typeof(T)).Cast<T>().Select(x => new SelectListItem() { 
        Text = x.ToString(),
        Value = x.ToString().Replace("_", " ")
    });

    return new SelectList(source);
}

Probably GetSelectList method contents in your side is slightly different, but the basics should be same with those approaches.

Similar issues:

How do I populate a dropdownlist with enum values?

Display enum in ComboBox with spaces

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Mvc Html.DropDownList on load replace some string

1 Answers1