private _Workbook _workBook = null;
private Worksheet _workSheet = null;
private Excel.Application _excelApplicatin = null;

_excelApplicatin = new Excel.Application();
_excelApplicatin.Visible = true;
_excelApplicatin.DisplayAlerts = true;

_workBook = _excelApplicatin.Workbooks.Add(XlSheetType.xlWorksheet);
_workSheet = (Worksheet)_workBook.ActiveSheet;
_workSheet.Name = "workSheetName";

//打开已存在的Excel
string strExcelPathName = AppDomain.CurrentDomain.BaseDirectory + "excelSheetName.xls";
Excel.Workbook workBook = application.Workbooks.Open(strExcelPathName, Type.Missing, Type.Missing,
              Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
              Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);


//读取已打开的Excel
Excel.Worksheet workSheet1 = (Excel.Worksheet)workBook.Sheets["SheetName1"];
Excel.Worksheet workSheet2 = (Excel.Worksheet)workBook.Sheets["SheetName2"];        

//添加一个workSheet
Worksheet workSheet = (Worksheet)workBook.Worksheets.Add(System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing);

//RowHeight   "1:1"表示第一行, "1:2"表示,第一行和第二行 
((Excel.Range)_workSheet.Rows["1:1", System.Type.Missing]).RowHeight = 100;

//ColumnWidth "A:B"表示第一列和第二列, "A:A"表示第一列
((Excel.Range)_workSheet.Columns["A:B", System.Type.Missing]).ColumnWidth = 10;

// EXCEL操作(需要冻结的字段 按住ALT+W 再按F)
 Excel.Range excelRange = _workSheet .get_Range(_workSheet .Cells[10, 5], _workSheet .Cells[10, 5]);
excelRange.Select();
excelApplication.ActiveWindow.FreezePanes = true;

//Borders.LineStyle 单元格边框线
Excel.Range excelRange = _workSheet.get_Range(_workSheet.Cells[2, 2], _workSheet.Cells[4, 6]);
//单元格边框线类型(线型,虚线型)
excelRange.Borders.LineStyle = 1;
excelRange.Borders.get_Item(XlBordersIndex.xlEdgeTop).LineStyle = Excel.XlLineStyle.xlContinuous;
//指定单元格下边框线粗细,和色彩
excelRange.Borders.get_Item(XlBordersIndex.xlEdgeBottom).Weight = Excel.XlBorderWeight.xlMedium;

excelRange.Borders.get_Item(XlBordersIndex.xlEdgeBottom).ColorIndex =3;

//设置字体大小
excelRange.Font.Size = 15;
//设置字体是否有下划线
excelRange.Font.Underline = true;  

//设置字体在单元格内的对其方式
excelRange.HorizontalAlignment = XlHAlign.xlHAlignCenter;
//设置单元格的宽度
excelRange.ColumnWidth = 15;
//设置单元格的背景色
excelRange.Cells.Interior.Color = System.Drawing.Color.FromArgb(255, 204, 153).ToArgb();
// 给单元格加边框
excelRange.BorderAround(XlLineStyle.xlContinuous, XlBorderWeight.xlThick, 
XlColorIndex.xlColorIndexAutomatic, System.Drawing.Color.Black.ToArgb());

//自动调整列宽
excelRange.EntireColumn.AutoFit();
// 文本水平居中方式
excelRange.HorizontalAlignment = Excel.XlHAlign.xlHAlignCenter;            
//文本自动换行
excelRange.WrapText = true;
//填充颜色为淡紫色
excelRange.Interior.ColorIndex = 39;

//合并单元格
excelRange.Merge(excelRange.MergeCells);
_workSheet.get_Range("A15", "B15").Merge(_workSheet.get_Range("A15", "B15").MergeCells);

/// <summary>
/// 常用颜色定义,对就Excel中颜色名
/// </summary>
public enum ColorIndex
{
   无色 = -4142,   自动 = -4105,   黑色 = 1,   褐色 = 53,   橄榄 = 52,   深绿 = 51,   深青 = 49,
   深蓝 = 11,   靛蓝 = 55,   灰色80 = 56,   深红 = 9,   橙色 = 46,   深黄 = 12,   绿色 = 10,
   青色 = 14,   蓝色 = 5,   蓝灰 = 47,   灰色50 = 16,   红色 = 3,   浅橙色 = 45,   酸橙色 = 43,
   海绿 = 50,   水绿色 = 42,   浅蓝 = 41,       紫罗兰 = 13,   灰色40 = 48,   粉红 = 7,
   金色 = 44,   黄色 = 6,   鲜绿 = 4,   青绿 = 8,   天蓝 = 33,   梅红 = 54,   灰色25 = 15,
   玫瑰红 = 38,   茶色 = 40,   浅黄 = 36,   浅绿 = 35,   浅青绿 = 34,   淡蓝 = 37,   淡紫 = 39,
   白色 = 2
}

    range.NumberFormatLocal = "@";     //设置单元格格式为文本
    range = (Range)worksheet.get_Range("A1", "E1");     //获取Excel多个单元格区域：本例做为Excel表头
    range.Merge(0);     //单元格合并动作
    worksheet.Cells[1, 1] = "Excel单元格赋值";     //Excel单元格赋值
    range.Font.Size = 15;     //设置字体大小
    range.Font.Underline=true;     //设置字体是否有下划线
    range.Font.Name="黑体";       设置字体的种类   
    range.HorizontalAlignment=XlHAlign.xlHAlignCenter;     //设置字体在单元格内的对其方式
    range.ColumnWidth=15;     //设置单元格的宽度
    range.Cells.Interior.Color=System.Drawing.Color.FromArgb(255,204,153).ToArgb();     //设置单元格的背景色
    range.Borders.LineStyle=1;     //设置单元格边框的粗细
    range.BorderAround(XlLineStyle.xlContinuous,XlBorderWeight.xlThick,XlColorIndex.xlColorIndexAutomatic,System.Drawing.Color.Black.ToArgb());     //给单元格加边框
    range.Borders.get_Item(Microsoft.Office.Interop.Excel.XlBordersIndex.xlEdgeTop).LineStyle = Microsoft.Office.Interop.Excel.XlLineStyle.xlLineStyleNone; //设置单元格上边框为无边框
        range.EntireColumn.AutoFit();     //自动调整列宽
    Range.HorizontalAlignment= xlCenter;     // 文本水平居中方式
    Range.VerticalAlignment= xlCenter     //文本垂直居中方式
    Range.WrapText=true;     //文本自动换行
    Range.Interior.ColorIndex=39;     //填充颜色为淡紫色
    Range.Font.Color=clBlue;     //字体颜色
    xlsApp.DisplayAlerts=false;     //保存Excel的时候，不弹出是否保存的窗口直接进行保存

 for (int i = 5; i < countRow + 1; i++)
            {
                string strKB = null;
                Microsoft.Office.Interop.Excel.Range kbrng = (Microsoft.Office.Interop.Excel.Range)sheSource.Cells[i, 1];
                if (kbrng.Value2 != null)
                    strKB = kbrng.Value2.ToString();
                if (strTotal.Contains(strKB))
                    kbrng.Interior.ColorIndex = 3;
            }