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C# WinForm導(dǎo)出Excel方法介紹

更新時間：2013年12月02日 10:30:06 作者：

在.NET應(yīng)用中，導(dǎo)出Excel是很常見的需求，導(dǎo)出Excel報表大致有以下三種方式：Office PIA，文件流和NPOI開源庫，本文只介紹前兩種方式

.NET開發(fā)人員首選的方法，通過COM組件調(diào)用Office軟件本身來實(shí)現(xiàn)文件的創(chuàng)建和讀寫，但是數(shù)據(jù)量較大的時候異常緩慢；如下代碼所示已經(jīng)做了優(yōu)化，將一個二維對象數(shù)組賦值到一個單元格區(qū)域中（下面的代碼中只能用于導(dǎo)出列數(shù)不多于26列的數(shù)據(jù)導(dǎo)出）：

Office PIA

復(fù)制代碼代碼如下:

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

這種方法的效率明顯高于第一種，而且也不需要安裝Office，但是導(dǎo)出的xls文件并不符合Excel的格式標(biāo)準(zhǔn)，在打開生成的xls文件時會提示：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.

復(fù)制代碼代碼如下:

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 + "\t");
        }
        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() + "\t");
            }
            sb.Append(Environment.NewLine);
        }
        sw.Write(sb.ToString());
        sw.Flush();
    }
    catch (IOException ioe)
    {
        throw ioe;
    }
    finally
    {
        if (sw != null)
        {
            sw.Close();
        }
    }
}