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  • 跟导师请教后写出的关于C#导出Excel,不导出隐藏列的方法

    首先,建立一个GridView,放入DataTable
    如图:

    打开栏目设计器的话,是对数据进行操作:

    我对aa bb两行数据,进行了隐藏操作:

    这样可以看到,aa bb在GridView中是隐藏了的,但是如果没有对新数据进行操作的话,导出的Excel是包含了aa bb两列的,所以,对新数据进行保存操作,很重要,代码抛出:

     1 private DataTable GetGridViewDT(GridView view)
     2         {
     3             if (view.RowCount == 0)
     4                 return null;
     5             DataTable dt = new DataTable();
     6             var cols = view.Columns.Where(p => p.Visible).OrderBy(p => p.VisibleIndex);
     7             for (int i = 0; i < view.RowCount; i++)
     8             {
     9                 List<object> values = new List<object>();
    10                 foreach (var col in cols)
    11                 {
    12                     object value = view.GetRowCellValue(i, col);
    13                     if (i == 0)//添加列名
    14                     {
    15                         dt.Columns.Add(col.FieldName, col.ColumnType);
    16                     }
    17                     values.Add(value);
    18                 }
    19                 dt.Rows.Add(values.ToArray());
    20             }
    21             return dt;
    22         }

    顺便给出ExcelHelper类:

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using NPOI.SS.UserModel;
    using NPOI.XSSF.UserModel;
    using NPOI.HSSF.UserModel;
    using System.IO;
    using System.Data;
    using System.ComponentModel;
    using System.Windows.Forms;
    using DevExpress.XtraGrid.Views.Grid;
    
    namespace RpnTest.Excel
    {
        public class ExcelHelperTrue : IDisposable
        {
            private string fileName = null; //文件名
            private IWorkbook workbook = null;
            private FileStream fs = null;
            private bool disposed;
    
            public ExcelHelperTrue(string fileName)
            {
                this.fileName = fileName;
                disposed = false;
            }
    
    
    
            /// <summary>
            /// 将DataTable数据导入到excel中
            /// </summary>
            /// <param name="data">要导入的数据</param>
            /// <param name="isColumnWritten">DataTable的列名是否要导入</param>
            /// <param name="sheetName">要导入的excel的sheet的名称</param>
            /// <returns>导入数据行数(包含列名那一行)</returns>
            public int DataTableToExcel(DataTable data, string sheetName, bool isColumnWritten)
            {
                int i = 0;
                int j = 0;
                int count = 0;
                ISheet sheet = null;
    
                fs = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);
                if (fileName.IndexOf(".xlsx") > 0) // 2007版本
                    workbook = new XSSFWorkbook();
                else if (fileName.IndexOf(".xls") > 0) // 2003版本
                    workbook = new HSSFWorkbook();
    
                try
                {
                    if (workbook != null)
                    {
                        sheet = workbook.CreateSheet(sheetName);
                    }
                    else
                    {
                        return -1;
                    }
                    if (isColumnWritten == true) //写入DataTable的列名
                    {
                        IRow row = sheet.CreateRow(0);
                        for (j = 0; j < data.Columns.Count; ++j)//遍历循环数据行
                        {
                            row.CreateCell(j).SetCellValue(data.Columns[j].ColumnName);//写入数据
                        }
                        count = 1;
                    }
                    else
                    {
                        count = 0;
                    }
    
                    for (i = 0; i < data.Rows.Count; ++i)
                    {
                        IRow row = sheet.CreateRow(count);
                        for (j = 0; j < data.Columns.Count; ++j)
                        {
                            CellType _datatype = GetExcelType(data.Columns[j].DataType.ToString());
                            row.CreateCell(j).SetCellValue(data.Rows[i][j].ToString());
                            switch (_datatype)
                            {
                                case CellType.Numeric:
                                    row.CreateCell(j).SetCellValue(Convert.ToDouble(data.Rows[i][j]));
                                    break;
                                case CellType.String:
                                    row.CreateCell(j).SetCellValue(Convert.ToString(data.Rows[i][j]));
                                    break;
                                case CellType.Formula:
                                    //IDataFormat datastyle = workbook.CreateDataFormat();
                                    var cell = row.CreateCell(j);
                                    cell.SetCellValue(Convert.ToDateTime(data.Rows[i][j]).ToString("yyyy-MM-dd"));
                                    //cell.CellStyle.DataFormat = datastyle.GetFormat("yyyy-MM-dd");
                                    break;
                                default:
                                    row.CreateCell(j).SetCellValue(data.Rows[i][j].ToString());
                                    break;
                            }
                            //cell.SetCellType(_datatype);
                            //if (_datatype == CellType.Formula)
                            //    cell.SetCellFormula("yyyy-MM-dd");
                        }
                        ++count;
                    }
                    workbook.Write(fs); //写入到excel
                    return count;
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Exception: " + ex.Message);
                    return -1;
                }
            }
            /// <summary>
            /// Numeric = 0,
            //String = 1,
            //Formula = 2,
            //Blank = 3,
            //Boolean = 4,
            /// </summary>
            /// <param name="type"></param>
            /// <returns></returns>
            /// 
            private CellType GetExcelType(string type)
            {
                CellType result = CellType.String;
                switch (type)
                {
                    case "System.Int32":
                    case "System.Decimal":
                    case "System.Double":
                        result = CellType.Numeric;
                        break;
                    case "System.DateTime":
                        result = CellType.Formula;
                        break;
                }
                return result;
            }
            /// <summary>
            /// 将excel中的数据导入到DataTable中
            /// </summary>
            /// <param name="sheetName">excel工作薄sheet的名称</param>
            /// <param name="isFirstRowColumn">第一行是否是DataTable的列名</param>
            /// <returns>返回的DataTable</returns>
            public DataTable ExcelToDataTable(string sheetName, bool isFirstRowColumn)
            {
                ISheet sheet = null;
                DataTable data = new DataTable();
                int startRow = 0;
                try
                {
                    fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
                    if (fileName.IndexOf(".xlsx") > 0) // 2007版本
                        workbook = new XSSFWorkbook(fs);
                    else if (fileName.IndexOf(".xls") > 0) // 2003版本
                        workbook = new HSSFWorkbook(fs);
    
                    if (sheetName != null)
                    {
                        sheet = workbook.GetSheet(sheetName);
                        if (sheet == null) //如果没有找到指定的sheetName对应的sheet,则尝试获取第一个sheet
                        {
                            sheet = workbook.GetSheetAt(0);
                        }
                    }
                    else
                    {
                        sheet = workbook.GetSheetAt(0);
                    }
                    if (sheet != null)
                    {
                        IRow firstRow = sheet.GetRow(0);
                        int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数
    
                        if (isFirstRowColumn)
                        {
                            for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
                            {
                                ICell cell = firstRow.GetCell(i);
                                if (cell != null)
                                {
                                    string cellValue = cell.StringCellValue;
                                    if (cellValue != null)
                                    {
                                        DataColumn column = new DataColumn(cellValue);
                                        data.Columns.Add(column);
                                    }
                                }
                            }
                            startRow = sheet.FirstRowNum + 1;
                        }
                        else
                        {
                            startRow = sheet.FirstRowNum;
                        }
    
                        //最后一列的标号
                        int rowCount = sheet.LastRowNum;
                        for (int i = startRow; i <= rowCount; ++i)
                        {
                            IRow row = sheet.GetRow(i);
                            if (row == null) continue; //没有数据的行默认是null       
    
                            DataRow dataRow = data.NewRow();
                            for (int j = row.FirstCellNum; j < cellCount; ++j)
                            {
                                if (row.GetCell(j) != null) //同理,没有数据的单元格都默认是null
                                    dataRow[j] = row.GetCell(j).ToString();
                            }
                            data.Rows.Add(dataRow);
                        }
                    }
    
                    return data;
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Exception: " + ex.Message);
                    return null;
                }
            }
    
            public void Dispose()
            {
                Dispose(true);
                GC.SuppressFinalize(this);
            }
    
            protected virtual void Dispose(bool disposing)
            {
                if (!this.disposed)
                {
                    if (disposing)
                    {
                        if (fs != null)
                            fs.Close();
                    }
    
                    fs = null;
                    disposed = true;
                }
            }
        }
    }

    最后,在窗体的button的单击事件代码中调用即可:

     private void toExcel1_Click(object sender, EventArgs e)
            {
                DataTable dt = GetGridViewDT(gridView1);
                SaveFileDialog dlg = new SaveFileDialog() { Filter = "Excel文件|*.xlsx" };
                if (dlg.ShowDialog() == DialogResult.OK)
                {
                    //string filename = DateTime.Now.ToString("yyyymmddhhmmss");
                    string filename = dlg.FileName;
                    using (ExcelHelperTrue helper = new ExcelHelperTrue(filename))
                    {
                        helper.DataTableToExcel(dt, "sheet", true);
                    }
                    Process.Start(filename);
                }
            }

     谢谢大家,将自己碰到的问题解决后,上传到博客园中,让更多与我一样碰到同样问题的同学能够尽快解决!

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  • 原文地址:https://www.cnblogs.com/lenglife/p/8258315.html
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