用什么封装？这里只是用了TagHelper，是啥？自己瞅文档去
在学习使用TagHelper的时候，最希望的就是能有个Demo能够让自己作为参考
- 怎么去封装一个组件？
- 不同的情况怎么去实现？
- 有没有更好更高效的方法？
找啊找啊找，最后跑去看了看mvc中的TagHelpers，再好好瞅了瞅TagHelper的文档
勉强折腾了几个组件出来，本来想一个组件一个组件写文章的，但是发现国庆已经结束了~
效果预览
代码仅供参考,有不同的意见也忘不吝赐教
Checkbox复选框组件封装
标签名称：cl-checkbox
标签属性： asp-for:绑定的字段，必须指定
- asp-items:绑定单选项 类型为：IEnumerable<SelectListItem>
- asp-skin:layui的皮肤样式，默认or原始
- asp-title:若只是一个复选框时显示的文字，且未指定items，默认Checkbox的值为true
其中在封装的时候看源代码发现两段非常有用的代码
1.判断是否可以多选：
复制代码 代码如下:
var realModelType = For.ModelExplorer.ModelType; //通过类型判断是否为多选 var _allowMultiple = typeof(string) != realModelType && typeof(IEnumerable).IsAssignableFrom(realModelType);
2.获取模型绑定的列表值(多选的情况)
复制代码 代码如下:
var currentValues = Generator.GetCurrentValues(ViewContext,For.ModelExplorer,expression: For.Name,allowMultiple: true);
这3句代码是在mvc自带的SelectTagHelper中发现的.
因为core其实已经提供了非常多的TagHelper,比如常用的select就是很好的参考对象，封装遇到问题的时候去找找看指不定就又意外的收获.
CheckboxTagHelper代码
using System.Collections.Generic;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.AspNetCore.Razor.TagHelpers;
namespace LayuiTagHelper.TagHelpers{
/// <summary> /// 复选框 /// </summary> /// <remarks> /// 当Items为空时显示单个，且选择后值为true /// </remarks> [HtmlTargetElement(CheckboxTagName)] public class CheckboxTagHelper : TagHelper {
private const string CheckboxTagName = "cl-checkbox";
private const string ForAttributeName = "asp-for";
private const string ItemsAttributeName = "asp-items";
private const string SkinAttributeName = "asp-skin";
private const string SignleTitleAttributeName = "asp-title";
protected IHtmlGenerator Generator {
get;
}
public CheckboxTagHelper(IHtmlGenerator generator) {
Generator = generator;
}
[ViewContext] public ViewContext ViewContext {
get;
set;
}
[HtmlAttributeName(ForAttributeName)] public ModelExpression For {
get;
set;
}
[HtmlAttributeName(ItemsAttributeName)] public IEnumerable<SelectListItem> Items {
get;
set;
}
[HtmlAttributeName(SkinAttributeName)] public CheckboxSkin Skin {
get;
set;
}
= CheckboxSkin.默认;
[HtmlAttributeName(SignleTitleAttributeName)] public string SignleTitle {
get;
set;
}
public override void Process(TagHelperContext context, TagHelperOutput output) {
//获取绑定的生成的Name属性 string inputName = ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(For?.Name);
string skin = string.Empty;
#region 风格 switch (Skin) {
case CheckboxSkin.默认: skin = "";
break;
case CheckboxSkin.原始: skin = "primary";
break;
}
#endregion #region 单个复选框 if (Items == null) {
output.TagName = "input";
output.TagMode = TagMode.SelfClosing;
output.Attributes.Add("type", "checkbox");
output.Attributes.Add("id", inputName);
output.Attributes.Add("name", inputName);
output.Attributes.Add("lay-skin", skin);
output.Attributes.Add("title", SignleTitle);
output.Attributes.Add("value", "true");
if (For?.Model?.ToString().ToLower() == "true") {
output.Attributes.Add("checked", "checked");
}
return;
}
#endregion #region 复选框组 var currentValues = Generator.GetCurrentValues(ViewContext,For.ModelExplorer,expression: For.Name,allowMultiple: true);
foreach (var item in Items) {
var checkbox = new TagBuilder("input");
checkbox.TagRenderMode = TagRenderMode.SelfClosing;
checkbox.Attributes["type"] = "checkbox";
checkbox.Attributes["id"] = inputName;
checkbox.Attributes["name"] = inputName;
checkbox.Attributes["lay-skin"] = skin;
checkbox.Attributes["title"] = item.Text;
checkbox.Attributes["value"] = item.Value;
if (item.Disabled) {
checkbox.Attributes.Add("disabled", "disabled");
}
if (item.Selected || (currentValues != null && currentValues.Contains(item.Value))) {
checkbox.Attributes.Add("checked", "checked");
}
output.Content.AppendHtml(checkbox);
}
output.TagName = "";
#endregion }
}
public enum CheckboxSkin {
默认, 原始 }
}
使用示例
@{
string sex="男";
var Items=new List<SelectListItem>() {
new SelectListItem() {
Text = "男", Value = "男" }
, new SelectListItem() {
Text = "女", Value = "女"}
, new SelectListItem() {
Text = "不详", Value = "不详",Disabled=true }
}
;
}
<cl-checkbox asp-items="Model.Items" asp-for="Hobby1" asp-skin="默认"></cl-checkbox><cl-checkbox asp-for="Hobby3" asp-title="单个复选框"></cl-checkbox>
Radio单选框组件封装
标签名称：cl-radio
- 标签属性： asp-for:绑定的字段，必须指定
- asp-items:绑定单选项 类型为：IEnumerable<SelectListItem>
太简单了，直接上代码了
RadioTagHelper代码
using System;
using System.Collections.Generic;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.AspNetCore.Razor.TagHelpers;
namespace LayuiTagHelper.TagHelpers{
/// <summary> /// 单选框 /// </summary> [HtmlTargetElement(RadioTagName)] public class RadioTagHelper : TagHelper {
private const string RadioTagName = "cl-radio";
private const string ForAttributeName = "asp-for";
private const string ItemsAttributeName = "asp-items";
[ViewContext] public ViewContext ViewContext {
get;
set;
}
[HtmlAttributeName(ForAttributeName)] public ModelExpression For {
get;
set;
}
[HtmlAttributeName(ItemsAttributeName)] public IEnumerable<SelectListItem> Items {
get;
set;
}
public override void Process(TagHelperContext context, TagHelperOutput output) {
if (For == null) {
throw new ArgumentException("必须绑定模型");
}
foreach (var item in Items) {
var radio = new TagBuilder("input");
radio.TagRenderMode = TagRenderMode.SelfClosing;
radio.Attributes.Add("id", ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(For.Name));
radio.Attributes.Add("name", ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(For.Name));
radio.Attributes.Add("value", item.Value);
radio.Attributes.Add("title", item.Text);
radio.Attributes.Add("type", "radio");
if (item.Disabled) {
radio.Attributes.Add("disabled", "disabled");
}
if (item.Selected || item.Value == For.Model?.ToString()) {
radio.Attributes.Add("checked", "checked");
}
output.Content.AppendHtml(radio);
}
output.TagName = "";
}
}
}
使用示例
@{
string sex="男";
var Items=new List<SelectListItem>() {
new SelectListItem() {
Text = "男", Value = "男" }
, new SelectListItem() {
Text = "女", Value = "女"}
, new SelectListItem() {
Text = "不详", Value = "不详",Disabled=true }
}
;
}
<cl-radio asp-items="@Items" asp-for="sex"></cl-radio>
最后再来一个开关组件
单个复选框其实可以直接用开关代替，恰巧layui中也有，于是也将开关单独的封装了一下，代码大同小异
就这个 
使用也简单： <cl-switch asp-for="Hobby4" asp-switch-text="开启|关闭"></cl-switch>
namespace LayuiTagHelper.TagHelpers{
/// <summary> /// 开关 /// </summary> [HtmlTargetElement(SwitchTagName)] public class SwitchTagHelper : TagHelper {
private const string SwitchTagName = "cl-switch";
private const string ForAttributeName = "asp-for";
private const string SwitchTextAttributeName = "asp-switch-text";
protected IHtmlGenerator Generator {
get;
}
public SwitchTagHelper(IHtmlGenerator generator) {
Generator = generator;
}
[ViewContext] public ViewContext ViewContext {
get;
set;
}
[HtmlAttributeName(ForAttributeName)] public ModelExpression For {
get;
set;
}
[HtmlAttributeName(SwitchTextAttributeName)] public string SwitchText {
get;
set;
}
= "ON|OFF";
public override void Process(TagHelperContext context, TagHelperOutput output) {
string inputName = ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(For?.Name);
output.TagName = "input";
output.TagMode = TagMode.SelfClosing;
if (For?.Model?.ToString().ToLower() == "true") {
output.Attributes.Add("checked", "checked");
}
output.Attributes.Add("type", "checkbox");
output.Attributes.Add("id", inputName);
output.Attributes.Add("name", inputName);
output.Attributes.Add("value", "true");
output.Attributes.Add("lay-skin", "switch");
output.Attributes.Add("lay-text", SwitchText);
}
}
}
总结
封装的还很粗糙，正常的使用是没问题的，若发现问题，还望指出。
因为layui是直接在页面加载后渲染的表单标签，故没有多少和layui相关的样式。
除了一些表单组件之外，其实还对选项卡，时间轴，分页，代码显示组件做了一些封装，这些后面再介绍了。
当然，有兴趣的朋友可以先去一睹为快看看都实现了哪些组件
WeDemo分支clone命令:git clone https://git.coding.net/yimocoding/WeDemo.git -b LayuiTagHelper
选项卡，时间轴，分页，代码显示等Demo打包下载
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。
