//lista os valores do enumerador nullable para disponibilizar na dropdownlist:
private static IEnumerable <SelectListItem> SetEnumNullableItems <TModel, TEnum>(this HtmlHelper <TModel> htmlHelper, Expression <Func <TModel, TEnum> > expression, List <Enum> listToExclude)
{
//obter os valores:
var metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
var values = Enum.GetValues(GetNonNullableModelType(metadata)).Cast <TEnum>();
var dicObjs = new Dictionary <object, string>();
var selected = "";
//para cada valor do enumerador que não pertença à lista de exclusão, adiciona à lista a apresentar e verifica se é o valor selecionado ou não:
foreach (var value in values.Where(value => listToExclude == null || (listToExclude != null && !listToExclude.Exists(i => i.Equals(value as Enum)))))
{
dicObjs.Add(value, (value as Enum).GetDescription());
if (metadata.Model != null && value.ToString() == metadata.Model.ToString())
{
selected = metadata.Model.ToString();
}
}
//forma a selectList com os dados obtidos em cima:
IEnumerable <SelectListItem> itens = new SelectList(dicObjs, "Key", "Value", selected);
if (metadata.IsNullableValueType)
{
itens = SingleEmptyItem.Concat(itens);
}
return(itens);
}
public static MvcHtmlString MyEnumDropDownListFor <TModel, TEnum>(this HtmlHelper <TModel> htmlHelper, Expression <Func <TModel, TEnum> > expression, IEnumerable <SelectListItem> modelActionsList)
{
ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
Type enumType = GetNonNullableModelType(metadata);
IEnumerable <TEnum> values = Enum.GetValues(enumType).Cast <TEnum>();
TypeConverter converter = TypeDescriptor.GetConverter(enumType);
IEnumerable <SelectListItem> items =
from value in values
select new SelectListItem
{
Text = converter.ConvertToString(value),
Value = converter.ConvertToString(value),
Selected = value.Equals(metadata.Model)
};
if (metadata.IsNullableValueType)
{
items = SingleEmptyItem.Concat(items);
}
return(htmlHelper.DropDownListFor(
expression,
items
));
}
public static MvcHtmlString EnumDropDownListSpecialFor <TModel, TEnum>(this HtmlHelper <TModel> htmlHelper, Expression <Func <TModel, TEnum> > expression, bool soloLectura = false)
{
ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
Type enumType = GetNonNullableModelType(metadata);
IEnumerable <TEnum> values = Enum.GetValues(enumType).Cast <TEnum>();
IEnumerable <SelectListItem> items = from value in values
select new SelectListItem
{
Text = GetEnumDescription(value),
Value = value.ToString(),
Selected = value.Equals(metadata.Model)
};
if (metadata.IsNullableValueType)
{
items = SingleEmptyItem.Concat(items).OrderBy(a => a.Value);
}
if (soloLectura)
{
var htmlAttributes = new { @class = "form-control", @disabled = "disabled" };
return(htmlHelper.DropDownListFor(expression, items, htmlAttributes));
}
else
{
var htmlAttributes = new { @class = "form-control" };
return(htmlHelper.DropDownListFor(expression, items, htmlAttributes));
}
}
/// <summary>
/// Renders a drop down list
/// </summary>
/// <param name="htmlHelper"></param>
/// <param name="name">Name of the select element</param>
/// <param name="options">Options</param>
/// <param name="htmlAttributes">HTML attributes for the select</param>
public static MvcHtmlString DropDownList(this HtmlHelper htmlHelper, string name, IEnumerable <string> options, object htmlAttributes = null)
{
var items = options.Select(o => new SelectListItem {
Value = o, Text = o, Selected = o == null
});
items = SingleEmptyItem.Concat(items);
return(htmlHelper.DropDownList(name, items, htmlAttributes));
}
public static MvcHtmlString EnumDropDownListForWithDescription <TModel, TEnum>(this HtmlHelper <TModel> htmlHelper, Expression <Func <TModel, TEnum> > expression, object htmlAttributes)
{
var metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
var enumType = GetNonNullableModelType(metadata);
var values = Enum.GetValues(enumType).Cast <TEnum>();
var items = from value in values
select new SelectListItem
{
Text = EnumExtensions.GetEnumDescription(value),
Value = value.ToString(),
Selected = value.Equals(metadata.Model)
};
if (metadata.IsNullableValueType)
{
items = SingleEmptyItem.Concat(items);
}
return(htmlHelper.DropDownListFor(expression, items, htmlAttributes));
}
/// <summary>
/// Creates a drop down list which is bound to an enum from the model.
/// </summary>
/// <typeparam name="TModel"></typeparam>
/// <typeparam name="TEnum"></typeparam>
/// <param name="htmlHelper"></param>
/// <param name="expression">The enum to be bound to the drop down list.</param>
/// <param name="htmlAttributes">Any HTML attributes to add on to the drop down list.</param>
/// <returns></returns>
public static MvcHtmlString EnumDropDownListFor <TModel, TEnum>(this HtmlHelper <TModel> htmlHelper, Expression <Func <TModel, TEnum> > expression, object htmlAttributes)
{
ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
Type enumType = GetNonNullableModelType(metadata);
IEnumerable <TEnum> values = Enum.GetValues(enumType).Cast <TEnum>();
IEnumerable <SelectListItem> items = from value in values
select new SelectListItem
{
Text = GetEnumName(value),
Value = value.ToString(),
Selected = value.Equals(metadata.Model)
};
// If the enum is nullable, add an 'empty' item to the collection
if (metadata.IsNullableValueType)
{
items = SingleEmptyItem.Concat(items);
}
return(htmlHelper.DropDownListFor(expression, items, htmlAttributes));
}
public static MvcHtmlString EnumDropDownListFor <TModel, TEnum>(this HtmlHelper <TModel> htmlHelper, Expression <Func <TModel, TEnum> > expression)
{
ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
Type enumType = GetNonNullableModelType(metadata);
IEnumerable <TEnum> values = Enum.GetValues(enumType).Cast <TEnum>();
IEnumerable <SelectListItem> items =
values.Select(value => new SelectListItem
{
Text = value.ToString(),
Value = value.ToString(),
Selected = value.Equals(metadata.Model)
});
if (metadata.IsNullableValueType)
{
items = SingleEmptyItem.Concat(items);
}
return(htmlHelper.DropDownListFor(
expression,
items
));
}
