Excel导入-----导出(包含所选和全部)操作

在做系统的时候，很多时候信息量太大，这时候就需要进行Excel表格信息的导入和导出，今天就来给大家说一下我使用Excel表格信息导入和导出的心得。

1：首先需要在前端显示界面View视图中添加导入Excel和导出Excel按钮：

<div class="btn-group">
                <button type="button" class="btn btn-success">
                    <i class="fa fa-download"></i>
                    @T("导出")
                </button>
                <button type="button" class="btn btn-success dropdown-toggle" data-toggle="dropdown" aria-expanded="false">
                    <span class="caret"></span>
                    <span class="sr-only">&nbsp;</span>
                </button>

                @* 导出全部的form提交 *@
                <ul class="dropdown-menu" role="menu">
                    <li class="divider"></li>
                    <form action="/控制器/ExportExcelAll"
                          method="post">
                        <li>
                            <button type="submit" name="exportexcel-all">
                                <i class="fa fa-file-excel-o"></i>
                                @T("导出到Excel(全部)")
                            </button>
                        </li>
                    </form>
                    <li>
                        <button type="button" id="exportexcel-selected">
                            <i class="fa fa-file-excel-o"></i>
                            @T("导出到Excel(所选)")
                        </button>
                    </li>
                </ul>
            </div>
            <button type="button" name="importexcel" class="btn bg-olive" data-toggle="modal" data-target="#importexcel-window">
                <i class="fa fa-upload"></i>
                @T("导入")
            </button>

这里注意，导出（所选）Excel是通过获取当下的表单的方式来导出数据的，导出是通过提交form表单实现的（原因为通过submit没有响应）

2：添加点击事件后弹出来的操作界面（importexcel-window）：通过 data 属性：在按钮上设置属性 data-toggle="modal"，同时设置 data-target="#identifier" 或 href="#identifier" 来指定要切换的特定的模态框（带有 id="identifier"）。通过 JavaScript：使用这种技术，您可以通过简单的一行 JavaScript 来调用带有 id="identifier" 的模态框：

$('#identifier').modal(options)

@*import GradeMessage form*@
<div id="importexcel-window" class="modal fade" tabindex="-1" role="dialog" aria-labelledby="importexcel-window-title">
    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
                <h4 class="modal-title" id="importexcel-window-title">@T("Admin.Common.ImportFromExcel")</h4>
            </div>
            @using (Html.BeginForm("ImportExcel", "GradeMessage", FormMethod.Post, new { enctype = "multipart/form-data" }))
            {
                <div class="form-horizontal">
                    <div class="modal-body">
                        @Html.AntiForgeryToken()

                        <div class="form-group">
                            <div class="col-md-2">
                                <div class="label-wrapper">
                                    <label class="control-label">
                                        @T("Admin.Common.ExcelFile")
                                    </label>
                                </div>
                            </div>
                            <div class="col-md-10">
                                <input type="file" id="importexcelfile" name="importexcelfile" class="form-control" />
                            </div>
                        </div>
                    </div>
                    <div class="modal-footer">
                        <button type="submit" class="btn btn-primary">
                            @T("Admin.Common.ImportFromExcel")
                        </button>
                    </div>
                </div>
            }
        </div>
    </div>
</div>

3.在控制器端添加导入Excel和导出Excel方法：

（1）导入Excel：

        public ActionResult ImportExcel()
        {

            try
            {
                var file = Request.Files["importexcelfile"];
                if (file != null && file.ContentLength > )
                {
                    _importManager.ImportGradeMessageFromXlsx(file.InputStream);
                }
                else
                {
                    ErrorNotification(_localizationService.GetResource("Admin.Common.UploadFile"));
                    return RedirectToAction("List");
                }
                SuccessNotification(_localizationService.GetResource("导入成功"));
                return RedirectToAction("List");
            }
            catch (Exception exc)
            {
                ErrorNotification(exc);
                return RedirectToAction("List");
            }
        }

这里面

_importManager.ImportGradeMessageFromXlsx(file.InputStream)

中_importManager是实例化接口并调用接口中的方法ImportFamiliesFromXlsx（）

添加成员变量_importManager：private readonly IImportManager _importManager;

接口IImportManager ：

public partial interface IImportManager
    {
        /// <summary>
        /// Import products from XLSX file
        /// </summary>
        /// <param name="stream">Stream</param>
        void ImportGradeMessageFromXlsx(Stream stream);
    }

接口方法的实现：

 public void ImportGradeMessageFromXlsx(Stream stream)
        {
            {

                using (var xlPackage = new ExcelPackage(stream))
                {   //得到第一个表的工作簿
                    var worksheet = xlPackage.Workbook.Worksheets.FirstOrDefault();
                    if (worksheet == null)
                        throw new NopException("No worksheet found");
                    //列的属性
                    var properties = new[]
                    {
                    "参赛者姓名",

                };
                    int iRow = ;//行
                    while (true)
                    {
                        bool allColumnsAreEmpty = true;
                        if (worksheet.Cells[iRow, ].Value != null && !String.IsNullOrEmpty(worksheet.Cells[iRow, ].Value.ToString()))
                        {
                            allColumnsAreEmpty = false;
                        }
                        if (allColumnsAreEmpty)
                            break;

                        string CompetitorName = ConvertColumnToString(worksheet.Cells[iRow, GetColumnIndex(properties, "参赛者姓名")].Value);

                        string EventName = ConvertColumnToString(worksheet.Cells[iRow, GetColumnIndex(properties, "赛事信息")].Value);//外键对应的名称

                        var gradeMessage = _gradeMessageService.GetAllGradeMessages().FirstOrDefault(f => f.CompetitorDocumentNumber == CompetitorDocumentNumber);//通过证件好查询所用的信息
                        bool newGradeMessage = false;
                        if (gradeMessage == null)
                        {
                            gradeMessage = new GradeMessage();
                            newGradeMessage = true;
                        }
                        gradeMessage.CompetitorName = CompetitorName;//此处在进行相应的属性值最好与之前设置列属性的顺序一致，并采用相同的英文名称

                        gradeMessage.GradeReleaseTime = DateTime.ParseExact(GradeReleaseTime, "yyyy-MM-dd", System.Globalization.CultureInfo.CurrentCulture);//将string转成DateTime

                        gradeMessage.GradeJudge = GradeJudge;
                        gradeMessage.EventId = _eventSystemMessageService.GetAllEventSystemMessages().FirstOrDefault(x => x.EventName == EventName).Id;//通过外键表的名称并查询处外键Id
              if (newGradeMessage)
                        {
                            _gradeMessageService.InsertGradeMessage(gradeMessage);
                        }
                        else
                        {
                            _gradeMessageService.UpdateGradeMessage(gradeMessage);
                        }
                        //next gradeMessage
                        iRow++;
                    }
                }
            }
        }

这样就可以通过Excel表格数据进行数据的导入了

注意：对于”可为空“的导入时需要判断（if-else）否则会出现”未将对象设置到对象实例“错误：例如

if (_groupRegistratorMessageService.GetAllGroupRegistratorMessages().FirstOrDefault(x => x.GroupName == GroupName)!=null)
                        {
                            registratorMessage.GroupId = _groupRegistratorMessageService.GetAllGroupRegistratorMessages().FirstOrDefault(x => x.GroupName == GroupName).Id;
                        }
                        else
                        {
                            registratorMessage.GroupId = null;
                        }

（2）将数据导出到Excel表格：

进行导出时与进行导入时的步骤大庭相径,不同的是一些接口的调用

(2.1)导出全部

  [HttpPost, ActionName("List")]

        [FormValueRequired("exportexcel-all")]
        public ActionResult ExportExcelAll()
        {
            var gradeMessages = _gradeMessageService.GetAllGradeMessages().ToList();
            try
            {
                var bytes = _exportManager.ExportGradeMessagesToXlsx(gradeMessages);

                return File(bytes, MimeTypes.TextXlsx, "gradeMessages.xlsx");
            }
            catch (Exception exc)
            {
                ErrorNotification(exc);
                return RedirectToAction("List");
            }
        }

同样的这里面的

_exportManager.ExportGradeMessagesToXlsx(gradeMessages)

是实现导出Excel方法的接口并调用方法ExportFamiliesToXlsx()

添加成员变量_exportManager：private readonly IExportManager _exportManager;

IExportManager 接口：

public partial interface IExportManager
{
       /// <summary>
        /// Export GradeMessage list to XLSX
        /// </summary>
        /// <param name="stream">Stream</param>
        /// <param name="families">Customers</param>
        byte[] ExportGradeMessagesToXlsx(IEnumerable<GradeMessage> GradeMessages);;//这里的GradeMessage是对应数据库的类 
}

IExportManager 接口实现：

 public byte[] ExportGradeMessagesToXlsx(IEnumerable<GradeMessage> GradeMessages)
        {
            var properties = new[]
{
                 new PropertyByName<GradeMessage>("参赛者姓名", p => p.CompetitorName),
                new PropertyByName<GradeMessage>("赛事信息", p=>GetGradeNameById(p.EventId)),//注意这里是不允许多层查询的只好通过自定义方法来传参查询

            };
            return ExportToXlsx(properties, GradeMessages);
        }

        /// <summary>
        /// 获取赛事系统名称（通过id找到名称）
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        private string GetGradeNameById(int id)
        {
            return _eventSystemMessageService.GetEventSystemMessageById(id).EventName;
        }

这样就可以完成功能了。

（2.2）导出（所选）

控制器中的方法：

     [HttpPost]
        public ActionResult ExportExcelSelected(string selectedIds)
        {

            var gradeMessages = new List<GradeMessage>();
            if (selectedIds != null)
            {
                var ids = selectedIds
                    .Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
                    .Select(x => Convert.ToInt32(x))
                    .ToArray();
                gradeMessages.AddRange(_gradeMessageService.GetGradeMessagesByIdCollection(ids));
            }

            try
            {
                byte[] bytes = _exportManager.ExportGradeMessagesToXlsx(gradeMessages);
                return File(bytes, MimeTypes.TextXlsx, "gradeMessages.xlsx");
            }
            catch (Exception exc)
            {
                ErrorNotification(exc);
                return RedirectToAction("List");
            }
        }

注意，这里是导出接口和实现方法和导出全部的一样。

视图端通过点击事件请求数据

@using (Html.BeginForm("ExportExcelSelected", "GradeMessage", FormMethod.Post, new { id = "export-excel-selected-form" }))
{
    @Html.AntiForgeryToken()
    <input type="hidden" id="selectedIds" name="selectedIds" value="" />
}
<script type="text/javascript">
    $(document).ready(function () {
        $('#exportexcel-selected').click(function (e) {
            e.preventDefault();
            var ids = selectedIds.join(",");
            $('#export-excel-selected-form #selectedIds').val(ids);
            $('#export-excel-selected-form').submit();
            return false;
        });
    });
</script>

这样就完成导入导出来。