一：C#导入导出EXCEL文件的类
代码如下：
首先将Microsoft Excel 14.0 Object Library 引用导入
using System; using System.Data; using System.Data.OleDb; namespace ZFSoft.Joint { public class ExcelIO { private int _ReturnStatus; private string _ReturnMessage; /// <summary> /// 执行返回状态 /// </summary> public int ReturnStatus { get { return _ReturnStatus; } } /// <summary> /// 执行返回信息 /// </summary> public string ReturnMessage { get { return _ReturnMessage; } } public ExcelIO() { } /// <summary> /// 导入EXCEL到DataSet /// </summary> /// <param name="fileName">Excel全路径文件名</param> /// <returns>导入成功的DataSet</returns> public DataTable ImportExcel(string fileName) { //判断是否安装EXCEL Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application(); if (xlApp == null) { _ReturnStatus = -1; _ReturnMessage = "无法创建Excel对象，可能您的计算机未安装Excel"; return null; } //判断文件是否被其他进程使用 Microsoft.Office.Interop.Excel.Workbook workbook; try { workbook = xlApp.Workbooks.Open(fileName, 0, false, 5, "", "", false, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "", true, false, 0, true, 1, 0); } catch { _ReturnStatus = -1; _ReturnMessage = "Excel文件处于打开状态，请保存关闭"; return null; } //获得所有Sheet名称 int n = workbook.Worksheets.Count; string[] SheetSet = new string[n]; System.Collections.ArrayList al = new System.Collections.ArrayList(); for (int i = 1; i <= n; i++) { SheetSet[i - 1] = ((Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[i]).Name; } //释放Excel相关对象 workbook.Close(null, null, null); xlApp.Quit(); if (workbook != null) { System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook); workbook = null; } if (xlApp != null) { System.Runtime.InteropServices.Marshal.ReleaseComObject(xlApp); xlApp = null; } GC.Collect(); //把EXCEL导入到DataSet DataSet ds = new DataSet(); DataTable table = new DataTable(); string connStr = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = " + fileName + ";Extended Properties=Excel 8.0"; using (OleDbConnection conn = new OleDbConnection(connStr)) { conn.Open(); OleDbDataAdapter da; string sql = "select * from [" + SheetSet[0] + "$] "; da = new OleDbDataAdapter(sql, conn); da.Fill(ds, SheetSet[0]); da.Dispose(); table = ds.Tables[0]; conn.Close(); conn.Dispose(); } return table; } /// <summary> /// 把DataTable导出到EXCEL /// </summary> /// <param name="reportName">报表名称</param> /// <param name="dt">数据源表</param> /// <param name="saveFileName">Excel全路径文件名</param> /// <returns>导出是否成功</returns> public bool ExportExcel(string reportName, System.Data.DataTable dt, string saveFileName) { if (dt == null) { _ReturnStatus = -1; _ReturnMessage = "数据集为空！"; return false; } bool fileSaved = false; Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application(); if (xlApp == null) { _ReturnStatus = -1; _ReturnMessage = "无法创建Excel对象，可能您的计算机未安装Excel"; return false; } Microsoft.Office.Interop.Excel.Workbooks workbooks = xlApp.Workbooks; Microsoft.Office.Interop.Excel.Workbook workbook = workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet); Microsoft.Office.Interop.Excel.Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[1];//取得sheet1 worksheet.Cells.Font.Size = 10; Microsoft.Office.Interop.Excel.Range range; long totalCount = dt.Rows.Count; long rowRead = 0; float percent = 0; worksheet.Cells[1, 1] = reportName; ((Microsoft.Office.Interop.Excel.Range)worksheet.Cells[1, 1]).Font.Size = 12; ((Microsoft.Office.Interop.Excel.Range)worksheet.Cells[1, 1]).Font.Bold = true; //写入字段 for (int i = 0; i < dt.Columns.Count; i++) { worksheet.Cells[2, i + 1] = dt.Columns[i].ColumnName; range = (Microsoft.Office.Interop.Excel.Range)worksheet.Cells[2, i + 1]; range.Interior.ColorIndex = 15; range.Font.Bold = true; } //写入数值 for (int r = 0; r < dt.Rows.Count; r++) { for (int i = 0; i < dt.Columns.Count; i++) { worksheet.Cells[r + 3, i + 1] = dt.Rows[r][i].ToString(); } rowRead++; percent = ((float)(100 * rowRead)) / totalCount; } //此行有可能会出错，解决办法见下面 range = worksheet.get_Range(worksheet.Cells[2, 1], worksheet.Cells[dt.Rows.Count + 2, dt.Columns.Count]); range.BorderAround(Microsoft.Office.Interop.Excel.XlLineStyle.xlContinuous, Microsoft.Office.Interop.Excel.XlBorderWeight.xlThin, Microsoft.Office.Interop.Excel.XlColorIndex.xlColorIndexAutomatic, null); if (dt.Rows.Count > 0) { range.Borders[Microsoft.Office.Interop.Excel.XlBordersIndex.xlInsideHorizontal].ColorIndex = Microsoft.Office.Interop.Excel.XlColorIndex.xlColorIndexAutomatic; range.Borders[Microsoft.Office.Interop.Excel.XlBordersIndex.xlInsideHorizontal].LineStyle = Microsoft.Office.Interop.Excel.XlLineStyle.xlContinuous; range.Borders[Microsoft.Office.Interop.Excel.XlBordersIndex.xlInsideHorizontal].Weight = Microsoft.Office.Interop.Excel.XlBorderWeight.xlThin; } if (dt.Columns.Count > 1) { range.Borders[Microsoft.Office.Interop.Excel.XlBordersIndex.xlInsideVertical].ColorIndex = Microsoft.Office.Interop.Excel.XlColorIndex.xlColorIndexAutomatic; range.Borders[Microsoft.Office.Interop.Excel.XlBordersIndex.xlInsideVertical].LineStyle = Microsoft.Office.Interop.Excel.XlLineStyle.xlContinuous; range.Borders[Microsoft.Office.Interop.Excel.XlBordersIndex.xlInsideVertical].Weight = Microsoft.Office.Interop.Excel.XlBorderWeight.xlThin; } //保存文件 if (saveFileName != "") { try { workbook.Saved = true; workbook.SaveCopyAs(saveFileName); fileSaved = true; } catch (Exception ex) { fileSaved = false; _ReturnStatus = -1; _ReturnMessage = "导出文件时出错,文件可能正被打开！ " + ex.Message; } } else { fileSaved = false; } //释放Excel对应的对象 if (range != null) { System.Runtime.InteropServices.Marshal.ReleaseComObject(range); range = null; } if (worksheet != null) { System.Runtime.InteropServices.Marshal.ReleaseComObject(worksheet); worksheet = null; } if (workbook != null) { System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook); workbook = null; } if (workbooks != null) { System.Runtime.InteropServices.Marshal.ReleaseComObject(workbooks); workbooks = null; } xlApp.Application.Workbooks.Close(); xlApp.Quit(); if (xlApp != null) { System.Runtime.InteropServices.Marshal.ReleaseComObject(xlApp); xlApp = null; } GC.Collect(); return fileSaved; } } }
这种写法可能出现，Object未包含get_range定义，解决办法是将get_range变为Range：
range = worksheet.Range[worksheet.Cells[2, 1], worksheet.Cells[dt.Rows.Count + 2, dt.Columns.Count]];
调用该类的具体使用，导入表中的数据到dataGridView，实际上也是先到dataset里面：
private void button1_Click(object sender, EventArgs e) { OpenFileDialog ofd = new OpenFileDialog(); ofd.Filter = "Excel Files|*.xlsx"; if (ofd.ShowDialog() == DialogResult.OK) { string filename = ofd.FileName; ExcelIO ex = new ExcelIO(); dataGridView1.DataSource = ex.ImportExcel(filename); } }
调用该类的具体使用，从数据库导出到Excel，实际上也是先到dataset里面：
private void button2_Click(object sender, EventArgs e) { CarTableAdapter ca = new CarTableAdapter(); DataSet1.CarDataTable table = ca.GetData(); ExcelIO ex = new ExcelIO(); ex.ExportExcel("qiche",table,@"C:UsersAdministratorDesktop例子.xlsx"); }
二：C# WinForm导出Excel方法
在.NET应用中，导出Excel是很常见的需求，导出Excel报表大致有以下三种方式：Office PIA，文件流和NPOI开源库，.NET开发人员首选的方法，通过COM组件调用Office软件本身来实现文件的创建和读写，但是数据量较大的时候异常缓慢；如下代码所示已经做了优化，将一个二维对象数组赋值到一个单元格区域中（下面的代码中只能用于导出列数不多于26列的数据导出）：
OFFICE PIA：
public static void ExportToExcel(DataSet dataSet, string outputPath) { Excel.ApplicationClass excel = new Excel.ApplicationClass(); Excel.Workbook workbook = excel.Workbooks.Add(Type.Missing); int sheetIndex = 0; foreach (System.Data.DataTable dt in dataSet.Tables) { object[,] data = new object[dt.Rows.Count + 1, dt.Columns.Count]; for (int j = 0; j < dt.Columns.Count; j++) { data[0, j] = dt.Columns[j].ColumnName; } for (int j = 0; j < dt.Columns.Count; j++) { for (int i = 0; i < dt.Rows.Count; i++) { data[i + 1, j] = dt.Rows[i][j]; } } string finalColLetter = string.Empty; string colCharset = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; int colCharsetLen = colCharset.Length; if (dt.Columns.Count > colCharsetLen) { finalColLetter = colCharset.Substring( (dt.Columns.Count - 1) / colCharsetLen - 1, 1); } finalColLetter += colCharset.Substring( (dt.Columns.Count - 1) % colCharsetLen, 1); Excel.Worksheet sheet = (Excel.Worksheet)workbook.Sheets.Add( workbook.Sheets.get_Item(++sheetIndex), Type.Missing, 1, Excel.XlSheetType.xlWorksheet); sheet.Name = dt.TableName; string range = string.Format("A1:{0}{1}", finalColLetter, dt.Rows.Count + 1); sheet.get_Range(range, Type.Missing).Value2 = data; ((Excel.Range)sheet.Rows[1, Type.Missing]).Font.Bold = true; } workbook.SaveAs(outputPath, Excel.XlFileFormat.xlWorkbookNormal, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Excel.XlSaveAsAccessMode.xlExclusive, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing); workbook.Close(true, Type.Missing, Type.Missing); workbook = null; excel.Quit(); KillSpecialExcel(excel); excel = null; GC.Collect(); GC.WaitForPendingFinalizers(); } [DllImport("user32.dll", SetLastError = true)] static extern int GetWindowThreadProcessId(IntPtr hWnd, out int processId); static void KillSpecialExcel(Excel.Application app) { try { if (app != null) { int processId; GetWindowThreadProcessId(new IntPtr(app.Hwnd), out processId); System.Diagnostics.Process.GetProcessById(processId).Kill(); } } catch (Exception ex) { throw ex; } }
文件流
这种方法的效率明显高于第一种，而且也不需要安装Office，但是导出的xls文件并不符合Excel的格式标准，在打开生成的xls文件时会提示：The file you are trying to open is in a different format that specified by the file extension. Verify that the file is not corrupted and is from a trusted source before opening the file.
public static void ExportToExcel(System.Data.DataSet ds, string path) { StreamWriter sw = null; try { long totalCount = ds.Tables[0].Rows.Count; sw = new StreamWriter(path, false, Encoding.Unicode); StringBuilder sb = new StringBuilder(); for (int i = 0; i < ds.Tables[0].Columns.Count; i++) { sb.Append(ds.Tables[0].Columns[i].ColumnName + " "); } sb.Append(Environment.NewLine); for (int i = 0; i < ds.Tables[0].Rows.Count; i++) { for (int j = 0; j < ds.Tables[0].Columns.Count; j++) { sb.Append(ds.Tables[0].Rows[i][j].ToString() + " "); } sb.Append(Environment.NewLine); } sw.Write(sb.ToString()); sw.Flush(); } catch (IOException ioe) { throw ioe; } finally { if (sw != null) { sw.Close(); } } }
三：WinForm项目开发中Excel用法实例解析
在实际项目的开发过程中，所涉及的EXCEL往往会比较复杂，并且列中还会带有一些计算公式，这就给读取带来了很大的困难，曾经尝试过一些免费的第三方dll，譬如Myxls，NPOI，IExcelDataReader都会出现一些问题，最后采用OLEDB形式读取，再x64操作系统上有点问题，不过采用小技巧即可解决。
namespace DBUtilHelpV2 { public class OLEDBExcelToolV2 { static readonly string xls = ".xls"; static readonly string xlsx = ".xlsx"; string _ExcelExtension = string.Empty;//后缀 string _ExcelPath = string.Empty;//路径 string _ExcelConnectString = string.Empty;//链接字符串 static bool _X64Version = false;//是否强制使用x64链接字符串，即xlsx形式 public OLEDBExcelToolV2(string excelPath, bool x64Version) { if (string.IsNullOrEmpty(excelPath)) throw new ArgumentNullException("excelPath"); if (!File.Exists(excelPath)) throw new ArgumentException("excelPath"); string _excelExtension = Path.GetExtension(excelPath); _ExcelExtension = _excelExtension.ToLower(); _ExcelPath = excelPath; _X64Version = x64Version; _ExcelConnectString = BuilderConnectionString(); } /// <summary> /// 创建链接字符串 /// </summary> /// <returns></returns> private string BuilderConnectionString() { Dictionary<string, string> _connectionParameter = new Dictionary<string, string>(); if (!_ExcelExtension.Equals(xlsx) && !_ExcelExtension.Equals(xls)) { throw new ArgumentException("excelPath"); } if (!_X64Version) { if (_ExcelExtension.Equals(xlsx)) { // XLSX - Excel 2007, 2010, 2012, 2013 _connectionParameter["Provider"] = "Microsoft.ACE.OLEDB.12.0;"; _connectionParameter["Extended Properties"] = "'Excel 12.0 XML;IMEX=1'"; } else if (_ExcelExtension.Equals(xls)) { // XLS - Excel 2003 and Older _connectionParameter["Provider"] = "Microsoft.Jet.OLEDB.4.0"; _connectionParameter["Extended Properties"] = "'Excel 8.0;IMEX=1'"; } } else { _connectionParameter["Provider"] = "Microsoft.ACE.OLEDB.12.0;"; _connectionParameter["Extended Properties"] = "'Excel 12.0 XML;IMEX=1'"; } _connectionParameter["Data Source"] = _ExcelPath; StringBuilder _connectionString = new StringBuilder(); foreach (KeyValuePair<string, string> parameter in _connectionParameter) { _connectionString.Append(parameter.Key); _connectionString.Append('='); _connectionString.Append(parameter.Value); _connectionString.Append(';'); } return _connectionString.ToString(); } /// <summary> /// Excel操作 /// DELETE不支持 /// </summary> /// <param name="sql"></param> /// <returns></returns> public int ExecuteNonQuery(string sql) { int _affectedRows = -1; using (OleDbConnection sqlcon = new OleDbConnection(_ExcelConnectString)) { try { sqlcon.Open(); using (OleDbCommand sqlcmd = new OleDbCommand(sql, sqlcon)) { _affectedRows = sqlcmd.ExecuteNonQuery(); } } catch (Exception) { return -1; } } return _affectedRows; } /// <summary> /// Excel操作 ///获取EXCEL内sheet集合 /// </summary> /// <param name="sql"></param> /// <returns></returns> public string[] GetExcelSheetNames() { DataTable _schemaTable = null; using (OleDbConnection sqlcon = new OleDbConnection(_ExcelConnectString)) { try { sqlcon.Open(); _schemaTable = sqlcon.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null); String[] _excelSheets = new String[_schemaTable.Rows.Count]; int i = 0; foreach (DataRow row in _schemaTable.Rows) { _excelSheets[i] = row["TABLE_NAME"].ToString().Trim(); i++; } return _excelSheets; } catch (Exception) { return null; } finally { if (_schemaTable != null) { _schemaTable.Dispose(); } } } } /// <summary> /// 读取sheet /// eg:select * from [Sheet1$] /// </summary> /// <param name="sql"></param> /// <returns></returns> public DataTable ExecuteDataTable(string sql) { using (OleDbConnection sqlcon = new OleDbConnection(_ExcelConnectString)) { try { using (OleDbCommand sqlcmd = new OleDbCommand(sql, sqlcon)) { using (OleDbDataAdapter sqldap = new OleDbDataAdapter(sqlcmd)) { DataTable _dtResult = new DataTable(); sqldap.Fill(_dtResult); return _dtResult; } } } catch (Exception) { return null; } } } /// <summary> /// 获取excel所有sheet数据 /// </summary> /// <returns>DataSet</returns> public DataSet ExecuteDataSet() { DataSet _excelDb = null; using (OleDbConnection sqlcon = new OleDbConnection(_ExcelConnectString)) { try { sqlcon.Open(); DataTable _schemaTable = sqlcon.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null); if (_schemaTable != null) { int i = 0; _excelDb = new DataSet(); foreach (DataRow row in _schemaTable.Rows) { string _sheetName = row["TABLE_NAME"].ToString().Trim(); string _sql = string.Format("select * from [{0}]", _sheetName); using (OleDbCommand sqlcmd = new OleDbCommand(_sql, sqlcon)) { using (OleDbDataAdapter sqldap = new OleDbDataAdapter(sqlcmd)) { DataTable _dtResult = new DataTable(); _dtResult.TableName = _sheetName; sqldap.Fill(_dtResult); _excelDb.Tables.Add(_dtResult); } } i++; } } } catch (Exception) { return null; } } return _excelDb; } } }
代码使用方法：
/// <summary> /// 合并EXCEL数据 /// </summary> /// <param name="_excelPath">excel路径</param> private void HandleMergeExcel(string _excelPath) { if (!string.IsNullOrEmpty(_excelPath)) { OLEDBExcelToolV2 _excelHelper = new OLEDBExcelToolV2(_excelPath, true); DataSet _excelSource = _excelHelper.ExecuteDataSet(); HandleExcelSource(_excelSource); } }
若在x64操作系统，将第二个参数设置true，并且按照AccessDatabaseEngine_X64.exe即可正常读取。