.NET Core 2.2 Web API 中简单/基本的页码编号和限制返回数据的大小

Question

I need to add easy page numbering and limiting the size of returned data in Web API to such a controller. The whole project is on GitHub as if someone would like to see more.

https://github.com/lukaszFD/IPI-PAN_WEB_API

public class Documentation
{
        private readonly DocumentationContext _doc;
        public Documentation()
        {
            _doc = new DocumentationContext();
        }
        public async Task<List<GrTables>> DBDocumentation()
        {
            List<GrTables> list = await Task.Run(() => _doc.GrTables.ToList()).ConfigureAwait(true);
            return list;
        }
}

public class GrTablesController : ControllerBase
{
        private readonly ILogger<GrTablesController> _logger;

        public GrTablesController(ILogger<GrTablesController> logger)
        {
            _logger = logger;
        }
        [HttpGet("Documentation/All")]
        public async Task<ActionResult<List<GrTables>>> GetGlobalRespositoryDocumentation()
        {
            var data = await new Documentation().DBDocumentation();

            if (data == null)
            {
                _logger.LogWarning("No data found for GetGlobalRespositoryDocumentation/Documentation/All");
                return NotFound();
            }
            return Ok(data);
        }
}

Answer 1

I would recommend using pagination on Your EF queries. Something like this:

  public async Task<List<GrTables>> GetPaginatedResult(int pageSize, int pageNumber)

  {
            var query = _doc.Set<GrTables>().AsQueryable();
            return await query.Skip((pageNumber - 1) * pageSize).Take(pageSize).ToListAsync();
  }

I also like to return the paginated data with info that helps to process and request more paginated data.

 public class PageMetadata
 {
        public int TotalRecordCount { get; set; }

        public string NextPageLink { get; set; }

        public string PreviousPageLink { get; set; }

        public string FirstPageLink { get; set; }

        public string LastPageLink { get; set; }

        public int ActualPage { get; set; }

        public int RecordsPerPage { get; set; }

        public int TotalPages { get; set; }
 }

 public class PagedResponse<TResponseModel>
 {
        public IEnumerable<TResponseModel> Records { get;  set; }

        public PageMetadata Metadata { get;  set; }
 }

[HttpGet]
public async Task<IActionResult> GetPagedServiceData(
            [FromQuery] int pageNumber,
            [FromQuery] int pageSize)
{
            var result  = await new Documentation().GetPaginatedResult(pageNumber, pageSize);
            return Ok(result);
}