详解asp.net core封装layui组件示例分享

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~

demo下载

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

1. asp-items:绑定单选项 类型为：ienumerable<selectlistitem>
2. asp-skin:layui的皮肤样式，默认or原始
3. 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：

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)

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

1. 标签属性： asp-for:绑定的字段，必须指定
2. 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

仓库地址

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。