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问题描述

有在ASP.NET MVC期货的 Html.RadioButtonList 扩展方法。有没有人发现了一个code的强类型版本 RadioButtonListFor< T> 。它看起来像这样一个观点:

 <%= Html.RadioButtonListFor(型号=> model.Item,Model.ItemList)%GT;


解决方案

下面是aspx页面使用

 <%= Html.RadioButtonListFor(M = GT; m.GenderRadioButtonList)%GT;

下面是视图模型

 公共类HomePageViewModel
{
    公共枚举GenderType
    {
        男,
        女
    }
    公共RadioButtonListViewModel< GenderType> GenderRadioButtonList {搞定;组; }    公共HomePageViewModel()
    {
        GenderRadioButtonList =新RadioButtonListViewModel< GenderType>
        {
            ID =性别,
            的SelectedValue = GenderType.Male,
            ListItems的=新名单< RadioButtonListItem< GenderType>>
            {
                新RadioButtonListItem< GenderType>的{text =男,值= GenderType.Male},
                新RadioButtonListItem< GenderType>的{text =女,值= GenderType.Female}
            }
        };
    }
}

下面是用于单选按钮列表视图模型

 公共类RadioButtonListViewModel< T>
{
    公共字符串ID {搞定;组; }
    私人ŧ了selectedValue;
    公共ŧ的SelectedValue
    {
        {返回了selectedValue; }
        组
        {
            了selectedValue =价值;
            UpdatedSelectedItems();
        }
    }    私人无效UpdatedSelectedItems()
    {
        如果(ListItems的== NULL)
            返回;        ListItems.ForEach(李= GT; li.Selected =等于(li.Value,的SelectedValue));
    }    私人列表< RadioButtonListItem< T>> listItems中;
    公开名单< RadioButtonListItem< T>> ListItems的
    {
        {返回时listItems; }
        组
        {
            时listItems =价值;
            UpdatedSelectedItems();
        }
    }
}公共类RadioButtonListItem< T>
{
    公共BOOL选择{搞定;组; }    公共字符串文本{搞定;组; }    公众的T值{搞定;组; }    公共重写字符串的ToString()
    {
        返回Value.ToString();
    }
}

下面是RadioButtonListFor扩展方法

 公共静态类HtmlHelperExtensions
{
    公共静态字符串RadioButtonListFor<的TModel,TRadioButtonListValue>(此的HtmlHelper<的TModel>的HtmlHelper,防爆pression< Func键<的TModel,RadioButtonListViewModel< TRadioButtonListValue>>>前pression)其中的TModel:类
    {
        返回htmlHelper.RadioButtonListFor(如pression,NULL);
    }    公共静态字符串RadioButtonListFor<的TModel,TRadioButtonListValue>(此的HtmlHelper<的TModel>的HtmlHelper,防爆pression< Func键<的TModel,RadioButtonListViewModel< TRadioButtonListValue>>>前pression,对象htmlAttributes)其中的TModel:类
    {
        返回htmlHelper.RadioButtonListFor(如pression,新RouteValueDictionary(htmlAttributes));
    }    公共静态字符串RadioButtonListFor<的TModel,TRadioButtonListValue>(此的HtmlHelper<的TModel>的HtmlHelper,防爆pression< Func键<的TModel,RadioButtonListViewModel< TRadioButtonListValue>>>前pression,IDictionary的<字符串对象> htmlAttributes),其中的TModel:类
    {
        VAR inputName = GetInputName(如pression);        RadioButtonListViewModel< TRadioButtonListValue>单选按钮列表=的GetValue(的HtmlHelper,前pression);        如果(单选按钮列表== NULL)
            返回的String.Empty;        如果(radioButtonList.ListItems == NULL)
            返回的String.Empty;        VAR divTag =新TagBuilder(分区);
        divTag.MergeAttribute(ID,inputName);
        divTag.MergeAttribute(类,无线);
        的foreach(在radioButtonList.ListItems VAR项)
        {
            VAR radioButtonTag =单选按钮(的HtmlHelper,inputName,新SelectListItem的{text = item.Text,选择= item.Selected,值= item.Value.ToString()},htmlAttributes);            divTag.InnerHtml + = radioButtonTag;
        }        返回divTag + htmlHelper.ValidationMessage(inputName,*);
    }    公共静态字符串GetInputName<的TModel,TProperty>(防爆pression<&Func键LT;的TModel,TProperty>>前pression)
    {
        如果(如pression.Body.NodeType ==前pressionType.Call)
        {
            VAR methodCallEx pression =(MethodCallEx pression)前pression.Body;
            字符串名称= GetInputName(methodCallEx pression);
            返回name.Substring(例如pression.Parameters [0] .Name.Length + 1);        }
        返回前pression.Body.ToString()子串(如pression.Parameters [0] .Name.Length + 1)。
    }    私人静态字符串GetInputName(MethodCallEx pression前pression)
    {
        // P => 。p.Foo.Bar()Baz.ToString()=> p.Foo或抛出...        VAR methodCallEx pression =前pression.Object作为MethodCallEx pression;
        如果(methodCallEx pression!= NULL)
        {
            返回GetInputName(methodCallEx pression);
        }
        返回前pression.Object.ToString();
    }    公共静态字符串单选按钮(这的HtmlHelper的HtmlHelper,字符串名称,SelectListItem的listItem,
                         IDictionary的<字符串对象> htmlAttributes)
    {
        VAR inputIdSb =新的StringBuilder();
        inputIdSb.Append(名)
            。附加(_)
            .Append(listItem.Value);        VAR SB =新的StringBuilder();        VAR建设者=新TagBuilder(输入);
        如果(listItem.Selected)builder.MergeAttribute(选中,检查);
        builder.MergeAttribute(类型,无线电);
        builder.MergeAttribute(价值,listItem.Value);
        builder.MergeAttribute(ID,inputIdSb.ToString());
        builder.MergeAttribute(名,名称+.SelectedValue);
        builder.MergeAttributes(htmlAttributes);
        sb.Append(builder.ToString(TagRenderMode.SelfClosing));
        sb.Append(RadioButtonLabel(inputIdSb.ToString(),listItem.Text,htmlAttributes));
        sb.Append(< BR>中);        返回sb.ToString();
    }    公共静态字符串RadioButtonLabel(字符串inputId,串displayText,
                                 IDictionary的<字符串对象> htmlAttributes)
    {
        VAR labelBuilder =新TagBuilder(标签);
        labelBuilder.MergeAttribute(代表,inputId);
        labelBuilder.MergeAttributes(htmlAttributes);
        labelBuilder.InnerHtml = displayText;        返回labelBuilder.ToString(TagRenderMode.Normal);
    }
    公共静态TProperty的GetValue<的TModel,TProperty>(的HtmlHelper<的TModel>的HtmlHelper,防爆pression< Func键<的TModel,TProperty>>前pression)其中的TModel:类
    {
        的TModel模型= htmlHelper.ViewData.Model;
        如果(型号== NULL)
        {
            返回默认值(TProperty);
        }
        FUNC<的TModel,TProperty> FUNC =前pression.Compile();
        返回FUNC(模型);
    }
}

There was an Html.RadioButtonList extension method in ASP.NET MVC Futures. Has anyone found a code for a strongly typed version RadioButtonListFor<T>. It would look like this in a view:

<%= Html.RadioButtonListFor(model=>model.Item,Model.ItemList) %>
解决方案

Here is the usage in the aspx page

    <%= Html.RadioButtonListFor(m => m.GenderRadioButtonList)%>

Here is the view model

public class HomePageViewModel
{
    public enum GenderType
    {
        Male,
        Female
    }
    public RadioButtonListViewModel<GenderType> GenderRadioButtonList { get; set; }

    public HomePageViewModel()
    {
        GenderRadioButtonList = new RadioButtonListViewModel<GenderType>
        {
            Id = "Gender",
            SelectedValue = GenderType.Male,
            ListItems = new List<RadioButtonListItem<GenderType>>
            {
                new RadioButtonListItem<GenderType>{Text = "Male", Value = GenderType.Male},
                new RadioButtonListItem<GenderType>{Text = "Female", Value = GenderType.Female}
            }
        };
    }
}

Here's the view model used for radio button lists

public class RadioButtonListViewModel<T>
{
    public string Id { get; set; }
    private T selectedValue;
    public T SelectedValue
    {
        get { return selectedValue; }
        set
        {
            selectedValue = value;
            UpdatedSelectedItems();
        }
    }

    private void UpdatedSelectedItems()
    {
        if (ListItems == null)
            return;

        ListItems.ForEach(li => li.Selected = Equals(li.Value, SelectedValue));
    }

    private List<RadioButtonListItem<T>> listItems;
    public List<RadioButtonListItem<T>> ListItems
    {
        get { return listItems; }
        set
        {
            listItems = value;
            UpdatedSelectedItems();
        }
    }
}

public class RadioButtonListItem<T>
{
    public bool Selected { get; set; }

    public string Text { get; set; }

    public T Value { get; set; }

    public override string ToString()
    {
        return Value.ToString();
    }
}

Here's the extension methods for RadioButtonListFor

public static class HtmlHelperExtensions
{
    public static string RadioButtonListFor<TModel, TRadioButtonListValue>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, RadioButtonListViewModel<TRadioButtonListValue>>> expression) where TModel : class
    {
        return htmlHelper.RadioButtonListFor(expression, null);
    }

    public static string RadioButtonListFor<TModel, TRadioButtonListValue>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, RadioButtonListViewModel<TRadioButtonListValue>>> expression, object htmlAttributes) where TModel : class
    {
        return htmlHelper.RadioButtonListFor(expression, new RouteValueDictionary(htmlAttributes));
    }

    public static string RadioButtonListFor<TModel, TRadioButtonListValue>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, RadioButtonListViewModel<TRadioButtonListValue>>> expression, IDictionary<string, object> htmlAttributes) where TModel : class
    {
        var inputName = GetInputName(expression);

        RadioButtonListViewModel<TRadioButtonListValue> radioButtonList = GetValue(htmlHelper, expression);

        if (radioButtonList == null)
            return String.Empty;

        if (radioButtonList.ListItems == null)
            return String.Empty;

        var divTag = new TagBuilder("div");
        divTag.MergeAttribute("id", inputName);
        divTag.MergeAttribute("class", "radio");
        foreach (var item in radioButtonList.ListItems)
        {
            var radioButtonTag = RadioButton(htmlHelper, inputName, new SelectListItem{Text=item.Text, Selected = item.Selected, Value = item.Value.ToString()}, htmlAttributes);

            divTag.InnerHtml += radioButtonTag;
        }

        return divTag + htmlHelper.ValidationMessage(inputName, "*");
    }

    public static string GetInputName<TModel, TProperty>(Expression<Func<TModel, TProperty>> expression)
    {
        if (expression.Body.NodeType == ExpressionType.Call)
        {
            var methodCallExpression = (MethodCallExpression)expression.Body;
            string name = GetInputName(methodCallExpression);
            return name.Substring(expression.Parameters[0].Name.Length + 1);

        }
        return expression.Body.ToString().Substring(expression.Parameters[0].Name.Length + 1);
    }

    private static string GetInputName(MethodCallExpression expression)
    {
        // p => p.Foo.Bar().Baz.ToString() => p.Foo OR throw...

        var methodCallExpression = expression.Object as MethodCallExpression;
        if (methodCallExpression != null)
        {
            return GetInputName(methodCallExpression);
        }
        return expression.Object.ToString();
    }

    public static string RadioButton(this HtmlHelper htmlHelper, string name, SelectListItem listItem,
                         IDictionary<string, object> htmlAttributes)
    {
        var inputIdSb = new StringBuilder();
        inputIdSb.Append(name)
            .Append("_")
            .Append(listItem.Value);

        var sb = new StringBuilder();

        var builder = new TagBuilder("input");
        if (listItem.Selected) builder.MergeAttribute("checked", "checked");
        builder.MergeAttribute("type", "radio");
        builder.MergeAttribute("value", listItem.Value);
        builder.MergeAttribute("id", inputIdSb.ToString());
        builder.MergeAttribute("name", name + ".SelectedValue");
        builder.MergeAttributes(htmlAttributes);
        sb.Append(builder.ToString(TagRenderMode.SelfClosing));
        sb.Append(RadioButtonLabel(inputIdSb.ToString(), listItem.Text, htmlAttributes));
        sb.Append("<br>");

        return sb.ToString();
    }

    public static string RadioButtonLabel(string inputId, string displayText,
                                 IDictionary<string, object> htmlAttributes)
    {
        var labelBuilder = new TagBuilder("label");
        labelBuilder.MergeAttribute("for", inputId);
        labelBuilder.MergeAttributes(htmlAttributes);
        labelBuilder.InnerHtml = displayText;

        return labelBuilder.ToString(TagRenderMode.Normal);
    }


    public static TProperty GetValue<TModel, TProperty>(HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression) where TModel : class
    {
        TModel model = htmlHelper.ViewData.Model;
        if (model == null)
        {
            return default(TProperty);
        }
        Func<TModel, TProperty> func = expression.Compile();
        return func(model);
    }
}

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09-25 18:52