C# 行数。长度==0） ResultDataTable.LoadDataRow（parentrow.ItemArray，true）； } //如果SecondDataTable行不在FirstDataTable中，请添加到ResultDataTable。 fo

行数。长度==0） ResultDataTable.LoadDataRow（parentrow.ItemArray，true）； } //如果SecondDataTable行不在FirstDataTable中，请添加到ResultDataTable。 foreach（ds.Tables[1].行中的DataRow parentrow） { DataRow[]childrows=parentrow.GetChildRows（r2）； if（childrows==null | | childrows.Length==0） ResultDataTable.LoadDataRow（parentrow.ItemArray，true）； } ResultDataTable.EndLoadData（）； } 返回结果数据表； } #端区 私有void ExportDataTableToExcel（DataTable dt，字符串strFilePath） { //创建要将栅格数据导出到的CSV文件。 StreamWriter sw=新StreamWriter（strFilePath，false）； //首先，我们将编写标题。 //DataTable dt=m_dsProducts.表[0]； int iColCount=dt.Columns.Count； 对于（int i=0；i这个答案我们得到的是不同之处，而不是相似之处？？！！

#region Properties
    public string Directory { get; set; }
    public string FirstFile { get; set; }
    public string FirstFileSheetName { get; set; }
    public string SecondFile { get; set; }
    public string SecondFileSheetName { get; set; }
    public DataTable ReturnDataSet { get; set; }
    public bool Excel2007 { get; set; }
    public bool UseHeader { get; set; }
#endregion

#region Constructor
    public ExcelHandler() { }

    public ExcelHandler(string Dir, string File1, string File1SheetName, string File2, string File2SheetName)
    {
        this.Directory = Dir;
        this.FirstFile = File1;
        this.SecondFile = File2;
        this.FirstFileSheetName = File1SheetName;
        this.SecondFileSheetName = File2SheetName;
    }
#endregion

    #region Match Files
    public DataTable CheckExcelFiles()
    {
        DataTable dtRet = new DataTable();
        //Read the first excel
        try
        {
            //Read the excel
            DataTable dt1 = GetDataTableFromExcel(this.Directory, this.FirstFile, this.FirstFileSheetName);
            DataTable dt2 = GetDataTableFromExcel(this.Directory, this.SecondFile, this.SecondFileSheetName);

            //Compare two
            dtRet = getDifferentRecords(dt1, dt2);
        }
        catch (Exception ex) { }
        return dtRet;
    }

    //Overload method to write to csv
    public void CheckExcelFiles(string strFilePath)
    {
        DataTable dtRet = new DataTable();
        //Read the first excel
        try
        {
            //Read the excel
            DataTable dt1 = GetDataTableFromExcel(this.Directory, this.FirstFile, this.FirstFileSheetName);
            DataTable dt2 = GetDataTableFromExcel(this.Directory, this.SecondFile, this.SecondFileSheetName);

            //Compare two
            dtRet = getDifferentRecords(dt1, dt2);
            ExportDataTableToExcel(dtRet, strFilePath);
        }
        catch (Exception ex) { }

    }

    //Get Datatable reading Excel
    private DataTable GetDataTableFromExcel(string strDir, string strFileName, string strSheetName)
    {
        var fileName = string.Format("{0}\\" + strFileName, strDir);
        string connectionString;
        if (Excel2007)
            //read a 2007 file  
            connectionString = string.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=\"Excel 8.0;HDR=" + (UseHeader == true ? "YES" : "NO") + ";\"", fileName);
        else
            //read a 97-2003 file  
            connectionString = string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=\"Excel 8.0;HDR=" + (UseHeader == true ? "YES" : "NO") + ";\"", fileName);  


        //var connectionString = string.Format("Provider=Microsoft.Jet.OLEDB.4.0; data source={0}; Extended Properties=Excel 8.0;", fileName);

        var adapter = new OleDbDataAdapter("SELECT * FROM [" + strSheetName + "$]", connectionString);
        var ds = new DataSet();
        adapter.Fill(ds, fileName + strSheetName);
        return ds.Tables[fileName + strSheetName];
    }

    //Compare datatables
    private DataTable CompareDataTable(DataTable A, DataTable B)
    {
        A.PrimaryKey = new DataColumn[] { A.Columns["PK"] };
        B.PrimaryKey = new DataColumn[] { B.Columns["PK"] };
        A.Merge(B, true); // this will add to A any records that are in B but not A 
        A.AcceptChanges();
        return A.GetChanges(DataRowState.Added); // returns records originally only in B
    }


    //Provided here http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/23703a85-20c7-4759-806a-fabf4e9f5be6/
    //Provided by Guo Surfer
    #region Compare two DataTables and return a DataTable with DifferentRecords  

    /// <summary>  
    /// Compare two DataTables and return a DataTable with DifferentRecords  
    /// </summary>  
    /// <param name="FirstDataTable">FirstDataTable</param>  
    /// <param name="SecondDataTable">SecondDataTable</param>  
    /// <returns>DifferentRecords</returns>  
    public DataTable getDifferentRecords(DataTable FirstDataTable, DataTable SecondDataTable)
    {
        //Create Empty Table  
        DataTable ResultDataTable = new DataTable("ResultDataTable");
        //use a Dataset to make use of a DataRelation object  
        using (DataSet ds = new DataSet())
        {
            //Add tables  
            ds.Tables.AddRange(new DataTable[] { FirstDataTable.Copy(), SecondDataTable.Copy() });
            //Get Columns for DataRelation  
            DataColumn[] firstColumns = new DataColumn[ds.Tables[0].Columns.Count];
            for (int i = 0; i < firstColumns.Length; i++)
            {
                firstColumns[i] = ds.Tables[0].Columns[i];
            }
            DataColumn[] secondColumns = new DataColumn[ds.Tables[1].Columns.Count];
            for (int i = 0; i < secondColumns.Length; i++)
            {
                secondColumns[i] = ds.Tables[1].Columns[i];
            }
            //Create DataRelation  
            DataRelation r1 = new DataRelation(string.Empty, firstColumns, secondColumns, false);
            ds.Relations.Add(r1);
            DataRelation r2 = new DataRelation(string.Empty, secondColumns, firstColumns, false);
            ds.Relations.Add(r2);
            //Create columns for return table  
            for (int i = 0; i < FirstDataTable.Columns.Count; i++)
            {
                ResultDataTable.Columns.Add(FirstDataTable.Columns[i].ColumnName, FirstDataTable.Columns[i].DataType);
            }
            //If FirstDataTable Row not in SecondDataTable, Add to ResultDataTable.  
            ResultDataTable.BeginLoadData();
            foreach (DataRow parentrow in ds.Tables[0].Rows)
            {
                DataRow[] childrows = parentrow.GetChildRows(r1);
                if (childrows == null || childrows.Length == 0)
                    ResultDataTable.LoadDataRow(parentrow.ItemArray, true);
            }
            //If SecondDataTable Row not in FirstDataTable, Add to ResultDataTable.  
            foreach (DataRow parentrow in ds.Tables[1].Rows)
            {
                DataRow[] childrows = parentrow.GetChildRows(r2);
                if (childrows == null || childrows.Length == 0)
                    ResultDataTable.LoadDataRow(parentrow.ItemArray, true);
            }
            ResultDataTable.EndLoadData();
        }
        return ResultDataTable;
    }

    #endregion  

    private void ExportDataTableToExcel(DataTable dt, string strFilePath)
    {
    // Create the CSV file to which grid data will be exported.
    StreamWriter sw = new StreamWriter(strFilePath, false);
    // First we will write the headers.
    //DataTable dt = m_dsProducts.Tables[0];
    int iColCount = dt.Columns.Count;
    for (int i = 0; i < iColCount; i++)
    {
        sw.Write(dt.Columns[i]);
        if (i < iColCount - 1)
        {
            sw.Write(",");
        }
    }
    sw.Write(sw.NewLine);
    // Now write all the rows.
    foreach (DataRow dr in dt.Rows)
    {
        for (int i = 0; i < iColCount; i++)
        {
            if (!Convert.IsDBNull(dr[i]))
            {
                sw.Write(dr[i].ToString());
            }
            if (i < iColCount - 1)
            {
                sw.Write(",");
            }
        }
        sw.Write(sw.NewLine);
    }
    sw.Close();

    }



    #endregion