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这两种方法目前如果遇到0开头的数据，会默认把0去掉，可以考虑如果StartsWith(“0”)，则在前面加个单引号（即’）

• 导出 Excel

/// 
/// 将 DataTable 转换为 Excel/// 需在 nuget 安装 DotNetCore.NPOI/// 
/// 数据表/// sheet名称/// 
   public static byte[] DataTableToExcel(DataTable table, string title = null, string sheetName = "Sheet"){    try    {        IWorkbook workbook = new XSSFWorkbook();        ISheet sheet = workbook.CreateSheet(sheetName);        int cellsIndex = 0;        // 标题        if (!string.IsNullOrEmpty(title))        {            // 填充数据            IRow cellsTitle = sheet.CreateRow(0);            cellsTitle.CreateCell(0).SetCellValue(title);            // 合并单元格            sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 1, 0, table.Columns.Count - 1));            cellsIndex = 2;        }        // 填充表头        IRow cellsHeader = sheet.CreateRow(cellsIndex);        for (int i = 0; i < table.Columns.Count; i++)        {            cellsHeader.CreateCell(i).SetCellValue(table.Columns[i].ColumnName);        }        // 填充数据        cellsIndex += 1;        foreach (DataRow dr in table.Rows)        {            IRow row = sheet.CreateRow(cellsIndex);            for (int i = 0; i < table.Columns.Count; i++)            {                row.CreateCell(i).SetCellValue(StrHelper.ToString(dr[i]));            }            cellsIndex++;        }        byte[] buffer = null;        using (MemoryStream ms = new MemoryStream())        {            workbook.Write(ms);            buffer = ms.GetBuffer();            ms.Close();        }        return buffer;    }    catch (Exception)    {        return null;    }}

• 导出 CSV

/// 
/// 将 DataTable 转换为 CSV/// 
/// 数据表/// 
   public static Stream DataTableToCsv(DataTable table){    try    {        StringBuilder builder = new StringBuilder();        DataColumn column;        int iColCount = table.Columns.Count;        // 处理表头        for (int i = 0; i < iColCount; i++)        {            if (i != 0) builder.Append(",");            builder.Append("\"" + table.Columns[i].ColumnName + "\"");        }        builder.AppendLine();        // 处理内容        foreach (DataRow row in table.Rows)        {            for (int i = 0; i < iColCount; i++)            {                column = table.Columns[i];                if (i != 0) builder.Append(",");                if (Convert.IsDBNull(row[column])) builder.Append("\"\"");                //else if (row[column].ToString().StartsWith("0")) builder.Append("\"'" + row[column].ToString() + "\"");                else builder.Append("\"" + row[column].ToString() + "\"");            }            builder.AppendLine();        }        byte[] bytes = Encoding.GetEncoding("GB2312").GetBytes(builder.ToString());        Stream stream = new MemoryStream(bytes);        return stream ;    }    catch (Exception)    {        return null;    }}

• .Net Core WebAPI Controller

/// 
/// 导出 Excel/// 
/// 
   [HttpGet("exportExcel")]public async Task
   
     ExportExcel(){    DataTable dataTable = new DataTable(); // 此处准备 dataTable 数据        string name = "数据详情";    byte[] bytes = Utils.DataTableToExcel(dataTable, name, name);    return File(bytes, "application/octet-stream", $"{name}_{DateTime.Now:yyyyMMddHHmmssfff}.xlsx");}/// 
    
/// 导出 CSV/// 
/// 
    [HttpGet("exportCSV")]public async Task
    
      ExportCSV(){    DataTable dataTable = new DataTable(); // 此处准备 dataTable 数据    System.IO.Stream stream = Utils.DataTableToCsv(dataTable);    return File(stream, "application/octet-stream", $"数据详情_{DateTime.Now:yyyyMMddHHmmssfff}.csv");}
    
   

• .Net Core Startup.cs 配置

这里配置 .WithExposedHeaders("Content-Disposition") 是因为 Vue Axios response.headers 中默认获取不到 content-disposition 属性

public void ConfigureServices(IServiceCollection services){	// ......	    // 处理 api 请求跨域    services.AddCors(options =>    {        options.AddPolicy("cors",            builder =>            {                builder.AllowAnyMethod()                .AllowAnyOrigin()                .AllowAnyHeader()                .WithExposedHeaders("Content-Disposition");            });    });	// ......}

• Vue Axios

service.interceptors.response.use(  response => {    // blob 直接返回文件流数据    if (response.config.responseType === 'blob') {      console.log(response.headers);      const fileName = decodeURI(      	// response.headers['content-disposition'] 默认获取不到，需要在 .Net Core Startup.cs 中进行配置        response.headers['content-disposition'].split('filename*=UTF-8\'\'')[1]      )      return Promise.resolve({ data: response.data, fileName: fileName })    }    // ......  },  error => {    return Promise.reject(error)  })

• Vue 请求接口

export function exportCSV(param) {    return request({        url: '/controller/exportCSV',        method: 'get',        params: { ...param },        responseType: 'blob'    })}

• Vue 下载实现

export default {  data() {    return {      listQuery: {},    };  },  created() {},  methods: {    // 导出报表    onExport() {      exportCSV(this.listQuery).then((response) => {        let blob = new Blob([response.data], { type: response.data.type });        // 针对于 IE 浏览器的处理, 因部分 IE 浏览器不支持 createObjectURL        if (window.navigator && window.navigator.msSaveOrOpenBlob) {          window.navigator.msSaveOrOpenBlob(blob, response.fileName);        } else {          var downloadElement = document.createElement("a");          var href = window.URL.createObjectURL(blob); // 创建下载的链接          downloadElement.href = href;          downloadElement.download = response.fileName; // 下载后文件名          document.body.appendChild(downloadElement);          downloadElement.click(); // 点击下载          document.body.removeChild(downloadElement); // 下载完成移除元素          window.URL.revokeObjectURL(href); // 释放掉 blob 对象        }      });    },  },};

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