谈到ASP.NET Web API的分页，考虑的因素包括：

1、上一页和下一页的uri

2、总数和总页数

3、当前页和页容量

接着是服务端的数据以怎样的形式返回？

我们通常这样写：

{

    totalCount:10,

    result: [

        {id:1, name:"a"},

        {id:2, name:"b"}

    ]

}

以上，把分页相关和实体信息以json格式返回给前端。但在本篇，尝试另外一种方式：把分页信息放在Header中返回给前端。

const int maxPageSize = 10;[Route("api/items", Name="items")]public IHttpActionResult Get(int page = 1, ing pageSize = 5){    try    {        var items = _repo.GetItem()            .sort()            .Where();                    if(pageSize > maxPageSize)        {            pageSize = maxPageSize;        }                var totalCount = items.Count();        var totalPages = (int)Math.Ceiling((double)totalCount/pageSize);                var urlHelper = new UrlHelper(Request);        var prevLink = page > 1 ? UrlHeloer.Link("items", new {            page = page -1,            pageSize = pageSize,            ...        }) : "";                var nextLink = page < totalPages? urlHelper.Link("items", new {            page = page + 1,            pageSize = pageSize,            ...        }) : "";                var paginationHeader = new         {            currentPage = page,            pageSize = pageSize,            totalCount = totalCount,            totalPages = totalPages,            previousPageLink = prevLink,            nextPageLink = nextLink        };                //放到Header中        HttpContext.Current.Response.Headers.Add("X-Pagination", Newtonsoft.Json.JsonConvert.SerializeObject(paginationHeader));                var result = items            .Skip(pageSize * (page - 1))            .Take(pageSize)            .ToList()            .Select(e => ItemFactory.CreateItem(e));                    return Ok(result);                }    catch(Exception)    {        //TODO:处理异常    }}

 

客户端发出如下请求：

localhost:4321/api/items?page=2&pagesize=2

在响应中有一个X-Pagination属性：

X-Pagination:{

    "currentPage":2,

    "pageSize":2,

    "totalPages":4,

    "previousPageLink": "http://localhost:4321/api/items?page=1&pageSize=2"

    "nextPageLink":"http://localhost:4321/api/items?page=3&pageSize=2"

}