• C#中NPOI操作excel之读取和写入excel数据


     一、下载引用

    下载需要引用的dll,即:NPOI.dll,NPOI.OOXML.dll,NPOI.OpenXml4Net.dll,ICSharpCode.SharpZipLib.dll(office2007版需要此dll)。

    二、excel转datatable类

    using System;
    using System.Data;
    using System.IO;
    using NPOI.SS.UserModel;
    using NPOI.HSSF.UserModel;
    using NPOI.XSSF.UserModel;
    using System.Collections.Generic;
    using System.Reflection;
    
    namespace IETMAuthor.Toolbox
    {
        public class ExcelUtility
        {
            /// <summary>  
            /// 将excel导入到datatable  
            /// </summary>  
            /// <param name="filePath">excel路径</param>  
            /// <param name="isColumnName">第一行是否是列名</param>  
            /// <returns>返回datatable</returns>  
            public static DataTable ExcelToDataTable(string filePath, bool isColumnName)
            {
                DataTable dataTable = null;
                FileStream fs = null;
                DataColumn column = null;
                DataRow dataRow = null;
                IWorkbook workbook = null;
                ISheet sheet = null;
                IRow row = null;
                ICell cell = null;  
                int startRow = 0;
                try
                {
                    using (fs = File.OpenRead(filePath))
                    {
                        // 2003版本  
                        if (filePath.IndexOf(".xls") > 0)
                            workbook = new HSSFWorkbook(fs);  
                        // 2007版本
                        else if (filePath.IndexOf(".xlsx") > 0)
                            workbook = new XSSFWorkbook(fs);
    
                        if (workbook != null)
                        {
                            sheet = workbook.GetSheetAt(0);//读取第一个sheet,当然也可以循环读取每个sheet  
                            dataTable = new DataTable();
                            if (sheet != null)
                            {
                                int rowCount = sheet.LastRowNum;//总行数  
                                if (rowCount > 0)
                                {
                                    IRow firstRow = sheet.GetRow(0);//第一行  
                                    int cellCount = firstRow.LastCellNum;//列数  
    
                                    //构建datatable的列  
                                    if (isColumnName)
                                    {
                                        startRow = 1;//如果第一行是列名,则从第二行开始读取  
                                        for (int i = firstRow.FirstCellNum; i < cellCount; i++)
                                        {
                                            cell = firstRow.GetCell(i);
                                            if (cell != null)
                                            {
                                                if (cell.StringCellValue != null)
                                                {
                                                    column = new DataColumn(cell.StringCellValue);
                                                    dataTable.Columns.Add(column);
                                                }
                                            }
                                        }
                                    }
                                    else
                                    {
                                        for (int i = firstRow.FirstCellNum; i < cellCount; i++)
                                        {
                                            column = new DataColumn("column" + (i + 1));
                                            dataTable.Columns.Add(column);
                                        }
                                    }
    
                                    //填充行  
                                    for (int i = startRow; i <= rowCount; i++)
                                    {
                                        row = sheet.GetRow(i);
                                        if (row == null) continue;
    
                                        dataRow = dataTable.NewRow();
                                        for (int j = row.FirstCellNum; j < cellCount; j++)
                                        {
                                            cell = row.GetCell(j);
                                            if (cell == null)
                                            {
                                                dataRow[j] = "";
                                            }
                                            else
                                            {
                                                switch (cell.CellType)
                                                {
                                                    case (NPOI.SS.UserModel.CellType)CellType.Blank:
                                                        dataRow[j] = "";
                                                        break;
                                                    case (NPOI.SS.UserModel.CellType)CellType.Numeric:
                                                        short format = cell.CellStyle.DataFormat;
                                                        //对时间格式(2015.12.5、2015/12/5、2015-12-5等)的处理  
                                                        if (format == 14 || format == 31 || format == 57 || format == 58)
                                                            dataRow[j] = cell.DateCellValue;
                                                        else
                                                            dataRow[j] = cell.NumericCellValue;
                                                        break;
                                                    case (NPOI.SS.UserModel.CellType)CellType.String:
                                                        dataRow[j] = cell.StringCellValue;
                                                        break;
                                                }
                                            }
                                        }
                                        dataTable.Rows.Add(dataRow);
                                    }
                                }
                            }
                        }
                    }
                    return dataTable;
                }
                catch (Exception)
                {
                    if (fs != null)
                    {
                        fs.Close();
                    }
                    return null;
                }
            }
    
    
            /// <summary>
            /// DataTable转List<T>
            /// </summary>
            /// <typeparam name="T">数据项类型</typeparam>
            /// <param name="dt">DataTable</param>
            /// <returns>List数据集</returns>
            public static List<T> DataTableToList<T>(DataTable dt) where T : new()
            {
                List<T> list = new List<T>();
                if (dt != null && dt.Rows.Count > 0)
                {
                    foreach (DataRow dr in dt.Rows)
                    {
                        T t = DataRowToModel<T>(dr);
                        list.Add(t);
                    }
                }
                return list;
            }
    
    
            /// <summary>
            /// DataRow转实体
            /// </summary>
            /// <typeparam name="IetmDmodule">数据型类</typeparam>
            /// <param name="dr">DataRow</param>
            /// <returns>模式</returns>
            public static T DataRowToModel<T>(DataRow dr) where T : new()
            {
                //T t = (T)Activator.CreateInstance(typeof(T));
                T t = new T();
                if (dr == null) return default(T);
                // 获得此模型的公共属性
                PropertyInfo[] propertys = t.GetType().GetProperties();
                DataColumnCollection Columns = dr.Table.Columns;
                foreach (PropertyInfo p in propertys)
                {
                    string columnName = p.Name;
                    if (Columns.Contains(columnName))
                    {
                        object value = dr[columnName];
                        if (value is DBNull || value == DBNull.Value) 
                            continue;
                        try
                        {
                            switch (p.PropertyType.ToString())
                            {
                                case "System.String":
                                    p.SetValue(t, Convert.ToString(value), null);
                                    break;
                                case "System.Int32":
                                    p.SetValue(t, Convert.ToInt32(value), null);
                                    break;
                                case "System.Int64":
                                    p.SetValue(t, Convert.ToInt64(value), null);
                                    break;
                                case "System.DateTime":
                                    p.SetValue(t, Convert.ToDateTime(value), null);
                                    break;
                                case "System.Boolean":
                                    p.SetValue(t, Convert.ToBoolean(value), null);
                                    break;
                                case "System.Double":
                                    p.SetValue(t, Convert.ToDouble(value), null);
                                    break;
                                case "System.Decimal":
                                    p.SetValue(t, Convert.ToDecimal(value), null);
                                    break;
                                default:
                                    p.SetValue(t, value, null);
                                    break;
                            }
                        }
                        catch (Exception ex)
                        {
                            continue;
                            /*使用 default 关键字,此关键字对于引用类型会返回空,对于数值类型会返回零。对于结构,
                             * 此关键字将返回初始化为零或空的每个结构成员,具体取决于这些结构是值类型还是引用类型*/
                        }
                    }
                }
                return t;
            }
    
        }
    
    
    
        enum CellType
        {
            Unknown = -1, Numeric = 0, String = 1, Formula = 2, Blank = 3, Boolean = 4, Error = 5
        }
    
    }

    三、结果

    四、写入excel类

        public static bool DataTableToExcel(DataTable dt)  
                {  
                    bool result = false;  
                    IWorkbook workbook = null;  
                    FileStream fs = null;  
                    IRow row = null;  
                    ISheet sheet = null;  
                    ICell cell = null;  
                    try  
                    {  
                        if (dt != null && dt.Rows.Count > 0)  
                        {  
                            workbook = new HSSFWorkbook();  
                            sheet = workbook.CreateSheet("Sheet0");//创建一个名称为Sheet0的表  
                            int rowCount = dt.Rows.Count;//行数  
                            int columnCount = dt.Columns.Count;//列数  
          
                            //设置列头  
                            row = sheet.CreateRow(0);//excel第一行设为列头  
                            for (int c = 0; c < columnCount; c++)  
                            {  
                                cell = row.CreateCell(c);  
                                cell.SetCellValue(dt.Columns[c].ColumnName);  
                            }                      
          
                            //设置每行每列的单元格,  
                            for (int i = 0; i <rowCount; i++)  
                            {  
                                row = sheet.CreateRow(i+1);  
                                for (int j = 0; j < columnCount; j++)  
                                {                              
                                    cell = row.CreateCell(j);//excel第二行开始写入数据  
                                    cell.SetCellValue(dt.Rows[i][j].ToString());                              
                                }  
                            }  
                            using (fs = File.OpenWrite(@"D:/myxls.xls"))   
                            {  
                                workbook.Write(fs);//向打开的这个xls文件中写入数据  
                                result = true;  
                            }  
                        }  
                        return result;  
                    }  
                    catch (Exception ex)  
                    {  
                        if (fs != null)  
                        {  
                            fs.Close();  
                        }  
                        return false;  
                    }  
                }  

    结果如下:

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  • 原文地址:https://www.cnblogs.com/jiangshuai52511/p/9178322.html
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