MVC扩展HtmlHelper实现CheckBoxList

MVC扩展HtmlHelper实现CheckBoxList

CheckBoxList在Web页面应用非常广泛,在传统的ASP.NET aspx中系统自带有CheckBoxList控件,但是在MVC Razer中没有提供,下面介绍通过扩展HtmlHelper实现CheckBoxList的方法

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  • C# 代码   复制
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    public static class CheckBoxListHelper
        {
            public static MvcHtmlString CheckBoxList(this HtmlHelper helper, string name, bool isHorizon = true)
            {
                return CheckBoxList(helper, name, helper.ViewData[name] as IEnumerable<SelectListItem>, new { }, isHorizon);
            }
    
            public static MvcHtmlString CheckBoxList(this HtmlHelper helper, string name, IEnumerable<SelectListItem> selectList, bool isHorizon = true)
            {
                return CheckBoxList(helper, name, selectList, new { }, isHorizon);
            }
    
            public static MvcHtmlString CheckBoxListFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, bool isHorizon = true)
            {
                string[] propertys  = expression.ToString().Split(".".ToCharArray());
                string id = string.Join("_", propertys, 1, propertys.Length - 1);
                string name = string.Join(".", propertys, 1, propertys.Length - 1);
    
                return CheckBoxList(helper, id, name, selectList, new { }, isHorizon);
            }
    
            public static MvcHtmlString CheckBoxList(this HtmlHelper helper, string name, IEnumerable<SelectListItem> selectList, object htmlAttributes, bool isHorizon = true)
            {
                return CheckBoxList(helper, name, name, selectList, htmlAttributes, isHorizon);
            }
    
            public static MvcHtmlString CheckBoxList(this HtmlHelper helper, string id, string name, IEnumerable<SelectListItem> selectList, object htmlAttributes, bool isHorizon = true)
            {
                IDictionary<string, object> HtmlAttributes = HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes);
    
                HashSet<string> set = new HashSet<string>();
                List<SelectListItem> list = new List<SelectListItem>();
                string selectedValues = (selectList as SelectList).SelectedValue == null ? string.Empty : Convert.ToString((selectList as SelectList).SelectedValue);
                if (!string.IsNullOrEmpty(selectedValues))
                {
                    if (selectedValues.Contains(","))
                    {
                        string[] tempStr = selectedValues.Split(',');
                        for (int i = 0; i < tempStr.Length; i++)
                        {
                            set.Add(tempStr[i].Trim());
                        }
    
                    }
                    else
                    {
                        set.Add(selectedValues);
                    }
                }
    
                foreach (SelectListItem item in selectList)
                {
                    item.Selected = (item.Value != null) ? set.Contains(item.Value) : set.Contains(item.Text);
                    list.Add(item);
                }
                selectList = list;
    
                HtmlAttributes.Add("type", "checkbox");
                HtmlAttributes.Add("id", id);
                HtmlAttributes.Add("name", name);
                HtmlAttributes.Add("style", "border:none;");
    
                StringBuilder stringBuilder = new StringBuilder();
    
                foreach (SelectListItem selectItem in selectList)
                {
                    IDictionary<string, object> newHtmlAttributes = HtmlAttributes.IDictionaryCopy();
                    newHtmlAttributes.Add("value", selectItem.Value);
                    if (selectItem.Selected)
                    {
                        newHtmlAttributes.Add("checked", "checked");
                    }
    
                    TagBuilder tagBuilder = new TagBuilder("input");
                    tagBuilder.MergeAttributes<string, object>(newHtmlAttributes);
                    string inputAllHtml = tagBuilder.ToString(TagRenderMode.SelfClosing);
                    string containerFormat = isHorizon ? @"<label> {0}  {1}</label>" : @"<p><label> {0}  {1}</label></p>";
                    stringBuilder.AppendFormat(containerFormat,
                       inputAllHtml, selectItem.Text);
                }
                return MvcHtmlString.Create(stringBuilder.ToString());
    
            }
            private static IDictionary<string, object> IDictionaryCopy(this IDictionary<string, object> ht)
            {
                Dictionary<string, object> _ht = new Dictionary<string, object>();
    
                foreach (var p in ht)
                {
                    _ht.Add(p.Key, p.Value);
                }
                return _ht;
            } 
        }
    
    		
  • 调用方式

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  • C# 代码   复制
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    @Html.CheckBoxList("保存SelectList的ViewData名称")
    
    或者
    
    @Html.CheckBoxList("CheckBoxList名称",new SelectList(IEnumerable items, string dataValueField, string dataTextField, object selectedValue),是否水平显示)
    
    或者
    
    					
    @Html.CheckBoxList("CheckBoxList名称",new SelectList(IEnumerable items, string dataValueField, string dataTextField, object selectedValue),其它html属性,是否水平显示)
    
            
    
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    @Html.CheckBoxListFor(m => m.aaa, new SelectList(IEnumerable items, string dataValueField, string dataTextField, object selectedValue),是否水平显示)
    
    		
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