合并属性 [英] Merging attributes
问题描述
public static IHtmlString CheckBoxWithLabelFor<TModel, TProperty>(this HtmlHelper<TModel> helper,
Expression<Func<TModel, TProperty>> expression, string labelText, object htmlAttributes)
{
var metadata = ModelMetadata.FromLambdaExpression(expression, helper.ViewData);
object currentValue = metadata.Model;
string property = ExpressionHelper.GetExpressionText(expression);
var checkBox = new TagBuilder("input");
checkBox.AddCssClass("checkBoxWithLabel");
checkBox.GenerateId(property);
checkBox.Attributes["type"] = "checkbox";
checkBox.Attributes["name"] = property;
checkBox.Attributes["value"] = "true";
checkBox.MergeAttributes(HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes),false);/*added false*/
var hidden = new TagBuilder("input");
hidden.Attributes["type"] = "hidden";
hidden.Attributes["name"] = property;
hidden.Attributes["value"] = "false";
if (Equals(currentValue, true))
{
checkBox.Attributes["checked"] = "checked";
}
var label = new TagBuilder("label");
label.AddCssClass("checkBoxLabel");
var htmlText = label.ToString().Replace("</label>", "");
htmlText += checkBox.ToString(TagRenderMode.SelfClosing);
htmlText += hidden.ToString(TagRenderMode.SelfClosing);
htmlText += labelText + "</label>";
return new HtmlString(htmlText);
AnonymousObjectToHtmlAttributes(htmlAttributes)仅将"_"替换为-".虽然MergeAttributes需要键/值类型,因此将忽略现有值.无法将对象HtmlAttributes更改/投射到具有IEnumerable,IDictionary等的Dictionary.我认为MergeAttributes应该在循环中以提取键/值,但不确定是什么开始滚滚滚动?
AnonymousObjectToHtmlAttributes(htmlAttributes) only replaces "_" with "-". Whilst MergeAttributes expects a key/value type and is therefore ignoring the existing values. Cant change/cast the object HtmlAttributes to a Dictionary with IEnumerable, IDictionary etc. I think MergeAttributes should be in a loop to extract the key/values but not sure what starts the ball rolling?
我希望类具有初始htmlAttributes值"editableInNew editableInUpdate readonly"元素以及添加有.AddCssClass的"checkBoxWithLabel"元素,但无法正常工作,我很沮丧.
I want class to have the initial htmlAttributes value "editableInNew editableInUpdate readonly" elements together with the "checkBoxWithLabel" added with .AddCssClass but cant get it work and I'm stumped.
推荐答案
您不应尝试在辅助程序中手动生成html,而应使用内置方法.您不仅在编写大量必要的代码,而且没有考虑到HtmlHelper的标准功能,例如绑定到ModelState
,客户端验证等(我认为您没有意识到).如果您确实想手动执行此操作,建议您学习
You should not be attempting to manually generate your html in the helper, but rather making use of the built-in methods. Not only are you writing significantly more code that necessary, your not taking into account standard HtmlHelper features such as binding to ModelState
, client side validation etc which I assume you are not aware of. If you do want to do this manually, I recommend you study the source code first.
您还应该更改助手的签名,以仅允许使用boolean
属性.
You should also change the signature of your helper to allow only boolean
properties.
public static IHtmlString CheckBoxWithLabelFor<TModel>(this HtmlHelper<TModel> helper,
Expression<Func<TModel, bool>> expression, string labelText, object htmlAttributes)
{
IDictionary<string, object> attributes = HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes);
// add the "checkBoxWithLabel" class
if (attributes.ContainsKey("class"))
{
attributes["class"] = "checkBoxWithLabel " + attributes["class"];
}
else
{
attributes.Add("class", "checkBoxWithLabel");
}
// build the html
StringBuilder html = new StringBuilder();
html.Append(helper.CheckBoxFor(expression, attributes));
html.Append(helper.LabelFor(expression, labelText, new { @class = "checkBoxLabel" }));
// suggest also adding the validation message placeholder
html.Append(helper.ValidationMessageFor(expression));
return MvcHtmlString.Create(html.ToString());
}
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