.NetCore 中如何实现分页以及编写一个URL分页

首先看下效果

这个分页控件不是很完美，体现下思路就行了，有兴趣的可以自己完善，我把代码贴出来，在这边文章中已有一些介绍

代码

 public class UosoPagerTagHelper : TagHelper
    {
        public UosoPagerOption UosoPagerOption { get; set; }

        public override void Process(TagHelperContext context, TagHelperOutput output)
        {
            output.TagName = "div";
            if (UosoPagerOption.CountNum < 1)
            {
                UosoPagerOption.CountNum = 5;
            }
            if (UosoPagerOption.PageIndex < 1)
            {
                UosoPagerOption.PageIndex = 1;
            }
            if (UosoPagerOption.PageIndex > UosoPagerOption.TotalPage)
            {
                UosoPagerOption.PageIndex = UosoPagerOption.TotalPage;
            }
            if (UosoPagerOption.TotalPage < 1)
            {
                return;
            }
            var queryarr = UosoPagerOption.Query.Where(c => c.Key != "pageindex" && c.Key != "pagesize").ToList();
            string queryurl = string.Empty;
            foreach (var item in queryarr)
            {
                queryurl += "&" + item.Key + "=" + item.Value;
            }

            output.Content.AppendFormat("<a class="prev" href="{0}?pageindex={1}&pagesize={2}{3}">首页</a>", UosoPagerOption.Url, 1, UosoPagerOption.PageSize, queryurl);
            if (UosoPagerOption.PageIndex == 1)
            {
                output.Content.AppendFormat("<a class="prev" href="{0}?pageindex={1}&pagesize={2}{3}">上一页</a>", UosoPagerOption.Url, 1, UosoPagerOption.PageSize, queryurl);
            }
            else {
                output.Content.AppendFormat("<a class="prev" href="{0}?pageindex={1}&pagesize={2}{3}">上一页</a>", UosoPagerOption.Url, UosoPagerOption.PageIndex - 1, UosoPagerOption.PageSize, queryurl);

            }
               
           
            #region 分页逻辑
            if (UosoPagerOption.PageIndex == 1)
            {
                for (int i = UosoPagerOption.PageIndex; i <= UosoPagerOption.PageIndex + UosoPagerOption.CountNum - 1; i++)
                {
                    if (i <= UosoPagerOption.TotalPage)
                    {
                        if (UosoPagerOption.PageIndex == i)
                        {
                            output.Content.AppendFormat("<span class="current">{0}</span>", i);
                        }
                        else
                        {
                            output.Content.AppendFormat("<a class="num" href="{0}?pageindex={1}&pagesize={2}{3}">{1}</a>", UosoPagerOption.Url, i, UosoPagerOption.PageSize, queryurl);

                        }
                    }
                }
            }

            else if (UosoPagerOption.PageIndex % UosoPagerOption.CountNum == 0)
            {
               
                for (int i = UosoPagerOption.PageIndex - (UosoPagerOption.CountNum / 2); i <= UosoPagerOption.PageIndex + UosoPagerOption.CountNum / 2; i++)
                {
                    if (i <= UosoPagerOption.TotalPage)
                    {
                        if (UosoPagerOption.PageIndex == i)
                        {
                            output.Content.AppendFormat("<span class="current">{0}</span>", i);
                        }
                        else
                        {
                            output.Content.AppendFormat("<a class="num" href="{0}?pageindex={1}&pagesize={2}{3}">{1}</a>", UosoPagerOption.Url, i, UosoPagerOption.PageSize, queryurl);

                        }
                    }
                }
            }
            else
            {
              
                int startindex = UosoPagerOption.CountNum * (UosoPagerOption.PageIndex / UosoPagerOption.CountNum) + 1;
                for (int i = startindex; i <= startindex + UosoPagerOption.CountNum - 1; i++)
                {
                    if (i <= UosoPagerOption.TotalPage)
                    {
                        if (UosoPagerOption.PageIndex == i)
                        {
                            output.Content.AppendFormat("<span class="current">{0}</span>", i);
                        }
                        else
                        {
                            output.Content.AppendFormat("<a class="num" href="{0}?pageindex={1}&pagesize={2}{3}">{1}</a>", UosoPagerOption.Url, i, UosoPagerOption.PageSize, queryurl);

                        }
                    }
                }

               

            }

            #endregion
            if (UosoPagerOption.PageIndex == UosoPagerOption.TotalPage)
            {
                output.Content.AppendFormat("<a class="next" href="{0}?pageindex={1}&pagesize={2}{3}">下一页</a>", UosoPagerOption.Url, UosoPagerOption.TotalPage, UosoPagerOption.PageSize, queryurl);
            }
            else
            {
                output.Content.AppendFormat("<a class="next" href="{0}?pageindex={1}&pagesize={2}{3}">下一页</a>", UosoPagerOption.Url, UosoPagerOption.PageIndex + 1, UosoPagerOption.PageSize, queryurl);
            }
            output.Content.AppendFormat("<a class="next" href="{0}?pageindex={1}&pagesize={2}{3}">尾页</a>", UosoPagerOption.Url, UosoPagerOption.TotalPage, UosoPagerOption.PageSize, queryurl);


            output.Content.AppendHtml("<div class="checkPageSize layui-form">" +
                "<select name="pageIndexSelect" lay-filter="pageSelect" lay-verify="required" class="pageIndexSelect" >" +
                "<option value="5" selected="selected">每页5条记录</option >" +
                "<option value="10" >每页10条记录</option>" +
                "<option value="20" > 每页20条记录</option>" +
                "<option value="50" > 每页50条记录</option>" +
                "<option value= "100"> 每页100条记录</option>" +
                "</select></div>");

            output.Content.AppendHtml("<label>跳转至&nbsp;&nbsp;</label><input type="number" autocomplete="of" placeholder="只能输入数字" id="goToPageIndex"/><label>&nbsp;&nbsp;页&nbsp;&nbsp;</label><input type="button" class="btn-default" value="确定" id="goBtn"/> ");

           base.Process(context, output);
        }
    }

   public class UosoPagerOption
    {
        public int PageIndex { get; set; }
        public int PageSize { get; set; }

        public int CountNum { get; set; }
        public int ItemCount { get; set; }
        public int TotalPage
        {
            get
            {
                return ItemCount % PageSize > 0 ? (ItemCount / PageSize + 1) : ItemCount / PageSize;
            }
        }
        public string Url { get; set; }

        public IQueryCollection Query { get; set; }
    }

用法

1、首先在自己项目中添加对应namespace 可以加到_ViewImports.cshtml中

@addTagHelper namespace.UosoPagerTagHelper, namespace

2、在Action 中列表代码中添加

 ViewBag.Option = new UosoPagerOption()
            {
                ItemCount = 数据总条数,
                PageSize = 每页显示多少条,
                PageIndex = 当前第几页,
                CountNum = 页码显示个数,
                Url = Request.Path.Value,
                Query = Request.Query
            };

3、在页面上我们添加

 <uoso-pager uoso-pager-option="@ViewBag.Option"></uoso-pager>

4、添加JS引用，这里可以根据自己的需求来写，我贴下，这里前端是用LayUI处理

layui.use('form', function () {
    //各种基于事件的操作，下面会有进一步介绍
    var form = layui.form;
    var url = "";
    form.on('select(pageSelect)', function (data) {
        url = document.location.pathname.toString();
        url = url + "?pageindex=1&pagesize=" + data.value;
        url = decodeURIComponent(url);
        window.location.href = url;
    });
    var pagesize = GetQueryString("pagesize");
    if (pagesize != null) {
        $("select[name='pageIndexSelect']").val(pagesize);
        form.render('select');
    }
    $("input[id='goToPageIndex']").keypress(function () {
        return (/[d]/.test(String.fromCharCode(event.keyCode)));
    });
    $("#goBtn").click(function () {
        var pageIndex = $("#goToPageIndex").val();
        if (pageIndex == null || pageIndex.toString() == '' || pageIndex == undefined) {
            layer.msg('页数不能为空');
            pageIndex = 0;
        } else if (pageIndex < 1) {
            layer.msg('页数不能小于1')
            pageIndex = 1;
        } else {
            url = document.location.pathname.toString();
            url = url + "?pageindex=" + pageIndex + "&pagesize=" + pagesize;
            window.location.href = url;
        }
       
    })
});
function GetQueryString(name) {
    var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)");
    var r = window.location.search.substr(1).match(reg);
    if (r != null) return unescape(r[2]); return null;
}

大概的思路就是这样子，代码仅供参考~