优化C#方法,比较并创建差异Excel文件

Question

这个问题与我之前的问题相关链接 下面的方法确实令我兴奋,但我需要让它运行得更快.有没有人有任何建议？谢谢.

        public bool createReport_NewMinusBase(string currentWorkingDirectory, string Book1, string Book2, double tolerance)
        {
            tolerance = 0.0001;
            myExcel.Application excelApp = new myExcel.Application();  // Creates a new Excel Application
            excelApp.Visible = false;  // Makes Excel visible to the user.
            excelApp.Application.DisplayAlerts = false;

            //useful for COM object interaction
            object missing = System.Reflection.Missing.Value;

            //Return value
            bool wereDifferences = false;

            //Comparison objects
            object objNew = null;
            object objBase = null;


            //source: http://www.codeproject.com/KB/office/csharp_excel.aspx
            //xlApp.Workbooks.Open(reportFolder + reportName, 0, false, 5, "", "", false, myExcel.XlPlatform.xlWindows, "", true, false, 0, true, false, false);

            //Open BASE FILE
            myExcel.Workbook excelWorkbook1 = excelApp.Workbooks.Open(@currentWorkingDirectory + Book1, 0,
                                              missing, missing, missing, missing, missing, missing, 
                                              missing,missing, missing, missing, missing, missing, missing);
            //OPEN NEW FILE
            myExcel.Workbook excelWorkbook2 = excelApp.Workbooks.Open(@currentWorkingDirectory + Book2, 0, 
                                              missing, missing, missing, missing, missing, missing, 
                                              missing, missing, missing, missing, missing, missing, missing);

            myExcel.Workbook excelWorkbook3 = excelApp.Application.Workbooks.Add(myExcel.XlWBATemplate.xlWBATWorksheet);

            myExcel.Worksheet wsBase;
            myExcel.Worksheet wsDiff;
            myExcel.Worksheet wsNew;


            try
            {
                wsBase = (myExcel.Worksheet)excelApp.Workbooks[Book1].Sheets["Sheet1"];
                wsNew = (myExcel.Worksheet)excelApp.Workbooks[Book2].Sheets["Sheet1"];
                wsDiff = (myExcel.Worksheet)excelWorkbook3.Worksheets.get_Item(1);
            }
            catch
            {
                throw new Exception("Excel file does not contain properly formatted worksheets");

            }


            //Copy Sheet from Excel Book "NEW" to "NEW(-)BASE"
            myExcel.Worksheet source_sheet;
            source_sheet = (myExcel.Worksheet)excelApp.Workbooks[Book2].Sheets["Sheet1"];
            source_sheet.UsedRange.Copy();
            wsDiff.Paste();




            //Determine working area
            int row = 0;
            int col = 0;
            int maxR = 0;
            int maxC = 0;

            int lr1 = 0;
            int lr2 = 0;
            int lc1 = 0;
            int lc2 = 0;
            {
                lr1 = wsNew.UsedRange.Rows.Count;
                lc1 = wsNew.UsedRange.Columns.Count;
            }

            {
                lr2 = wsBase.UsedRange.Rows.Count;
                lc2 = wsBase.UsedRange.Columns.Count;
            }

            maxR = lr1;
            maxC = lc1;

            if (maxR < lr2) maxR = lr2;
            if (maxC < lc2) maxC = lc2;

            //===================================================
            //Compare Cells
            //===================================================

            for (row = 1; row <= maxR; row++)
            {
                for (col = 1; col <= maxC; col++)
                {
                    //Get cell values
                    objNew = ((myExcel.Range)wsNew.Cells[row, col]).Value2;
                    objBase = ((myExcel.Range)wsBase.Cells[row, col]).Value2;


                    //If they are not equivilante
                    if (!equiv(objNew, objBase, tolerance))
                    {
                        wereDifferences = true;

                        //Mark differing cells
                        ((myExcel.Range)wsNew.Cells[row, col]).Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);
                        ((myExcel.Range)wsBase.Cells[row, col]).Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);

                        if ((objNew == null))
                        {                            
                            ((myExcel.Range)wsDiff.Cells[row, col]).Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);
                        }
                        else if (objNew.GetType().ToString() == "System.String")
                        {
                            ((myExcel.Range)wsDiff.Cells[row, col]).Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);
                        }
                        else
                        {
                            ((myExcel.Range)wsDiff.Cells[row, col]).Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Yellow);
                            ((myExcel.Range)wsDiff.Cells[row, col]).Value2 = ((myExcel.Range)wsNew.Cells[row, col]).Value2 - ((myExcel.Range)wsBase.Cells[row, col]).Value2;
                        }
                    }
                    else //They are equivalent
                    {                        
                        if ((objNew == null))
                        {
                        }
                        else if (objNew.GetType().ToString() == "System.String")
                        {
                        }
                        else
                        {                            
                            ((myExcel.Range)wsDiff.Cells[row, col]).Value2 = ((myExcel.Range)wsNew.Cells[row, col]).Value2 - ((myExcel.Range)wsBase.Cells[row, col]).Value2;
                        }
                    }
                }
            }


            // Copy formatting
            myExcel.Range range1 = wsBase.get_Range((myExcel.Range)wsBase.Cells[1, 1], (myExcel.Range)wsBase.Cells[maxR, maxC]);
            myExcel.Range range2 = wsDiff.get_Range((myExcel.Range)wsDiff.Cells[1, 1], (myExcel.Range)wsDiff.Cells[maxR, maxC]);
            range1.Copy();
            range2.PasteSpecial(myExcel.XlPasteType.xlPasteColumnWidths);

            excelApp.Workbooks[Book1].Close(false, false, false);
            excelApp.Workbooks[Book2].Close(false, false, false);

            string Book3 = "reporttestpc.xlsx"; //"reportBaseMinusNew.xlsx"
            if (File.Exists(currentWorkingDirectory + Book3))
            {
                File.Delete(currentWorkingDirectory + Book3);
            }

            excelWorkbook3.SaveAs(currentWorkingDirectory + Book3, Type.Missing, Type.Missing,
                                 Type.Missing, false, false, myExcel.XlSaveAsAccessMode.xlNoChange,
                                 Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);

            //excelApp.Workbooks[Book3].Close(false, false, false);

            excelApp.Visible = true;
            return wereDifferences;
        }


        /// Determines whether two objects are equivalent
        /// Numbers are equivalent within the specified tolerance
        /// Strings are equivalent if they are identical
        /// obj1 and obj2 are the two objects being compared
        /// tolerance is the maximum difference between two numbers for them to be deemed equivalent

        private bool equiv(object obj1, object obj2, double tolerance)
        {
            if ((obj1 == null) && (obj2 == null))
            {
                return true;
            }
            else if ((obj1 == null) || (obj2 == null))
            {
                return false;
            }

            //if both are numeric
            if (IsNumeric(obj1))
            {
                if (IsNumeric(obj2))
                {
                    if (Math.Abs(Convert.ToDouble(obj2) - Convert.ToDouble(obj1)) < tolerance)
                    {
                        return true;    //If they are within tolerance
                    }
                    else
                    {
                        return false;   //If they are outside tolerance
                    }
                }
                else
                {
                    return false;       //If only one is numeric
                }
            }

            //Now assuming both are just random strings
            else
            {
                if ((string)obj1 == (string)obj2)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
        }


        // Test whether a given object represents a number
        internal static bool IsNumeric(object ObjectToTest)
        {
            if (ObjectToTest == null)
            {
                return false;
            }
            else
            {
                double OutValue;
                return double.TryParse(ObjectToTest.ToString().Trim(),
                    System.Globalization.NumberStyles.Any,
                    System.Globalization.CultureInfo.CurrentCulture,
                    out OutValue);
            }
        }

    ///

Answer 1

建议1:

使:

objNew.GetType().ToString() == "System.String"

这个:

objNew is string

很清洁,对吗？应该更快.

建议2:

你打这个电话很多:

((myExcel.Range)wsDiff.Cells[row, col]

将结果存储在变量中并重用它.所有这些索引器,属性和装箱/拆箱都会产生开销.对于您反复访问相同COM方法,属性或索引器的任何位置也是如此.确保将这些变量声明在for循环的范围之外,如果它们进入和退出循环的每次迭代的范围,将会损害性能.

建议3:

您可以重用Excel Application对象吗？看起来每次调用此方法时都会创建一个新的.你可以把它存储在你班级的成员变量中吗？