Excel简单读写操作

Excel的程序集来自与Excel，所以如果在C#中遇到自己不懂的东西，不妨打开Excel的VBA工具，录制宏然后查看其中的操作代码。虽然好多的功能都通过import特征引入到C#中，但是深层的属性和方法都没有实现（已动态对象存在）。

这里我是从 .Sql中读取sql执行，并按照一定的格式写入Excel的。

这里主要用到的Excel相关方法与类有：

Microsoft.Office.Interop.Excel.Application//获取
Microsoft.Office.Interop.Excel.Workbook//相当于一个Excel文件
Microsoft.Office.Interop.Excel.Worksheet//相当于一个sheet

Application.WorkBooks//所有打开的workbook

WorkBooks.WorkSheets//工作表的所有sheet

WorkBooks.Add()//添加一个（在内存中）workbook

WorkSheets.Add()//在workbook中添加一个sheet

WorkSheets.get_Range("a1:b5")//获取一个区域，区域可以是一个Cell也可以是Cell的集合。

Range.Rows.Count//range的行数

ws.Cells[1,2]="Cell值"//设置Cell的值

WorkBook.SaveTo("path");//保存到指定文件

WorkBook.Close()//关闭workbook

Appliction.Quit()//关闭Excel进程

Process.GetProcesses()//获取当前进程列表

System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application")//获取正在运行的对象的实例。

public void FillExcel(string connStr,string sql,System.Data.SqlClient.SqlParameter[] parame,string formatfile,string saveTo,string fileName,bool allowRep) {
    string querystring;
    object Nothing = System.Reflection.Missing.Value;
    Microsoft.Office.Interop.Excel.Application app = null;
    Microsoft.Office.Interop.Excel.Workbook wb = null;
    Microsoft.Office.Interop.Excel.Worksheet ws = null;
    app = getAppliction();
    if (sql.Contains(@"") && System.IO.File.Exists(sql))
    {
        querystring = System.IO.File.ReadAllText(sql, Encoding.GetEncoding(936));//*.sql文件默认为gb2312编码
    }
    else {
        querystring = sql;
    }
    Dictionary<int, FileRule> formatrule = getFormatRule(formatfile);
    if (!System.IO.File.Exists(saveTo + @"" + fileName))
    {
                
        wb = app.Workbooks.Add(Nothing);
        if (wb.Worksheets.Count == 0)
        {
            ws = wb.Worksheets.Add();
            ws.Name = "插入";
        }
        else {
            ws = wb.ActiveSheet;
        }
    }
    else {
        Console.WriteLine("此文件已经存在！" + saveTo + @"" + fileName);
    reinput:
        Console.WriteLine("是否覆盖？（Y：覆盖|N：打开并写入|L：另存在）");
        ConsoleKeyInfo ck = Console.ReadKey(true);

        if (ck.Key == ConsoleKey.Y)
        {
            System.IO.File.Delete(saveTo + @"" + fileName);
            wb = app.Workbooks.Add(Nothing);
            if (wb.Worksheets.Count == 0)
            {
                ws = wb.Worksheets.Add();
            }
            else {
                ws = wb.ActiveSheet;
            }
        }
        else if (ck.Key == ConsoleKey.N)
        {
            wb = app.Workbooks.Open(saveTo + @"" + fileName);
            ws = wb.Worksheets.Add();
        }
        else if (ck.Key == ConsoleKey.L)
        {
            string message = "请输入新的文件名：";
            bool isavalid=false;
            while (!isavalid) {
                Console.WriteLine("请输入新的文件名：");
                string fn= Console.ReadLine();
                if (fn.TrimEnd().EndsWith(".xlsx") || fn.TrimEnd().EndsWith(".lsx"))
                {
                    if (System.IO.File.Exists(fn))
                    {
                        isavalid = false;
                        message = "此文件在目录中已存在，请重新输入！";
                    }
                    else
                    {
                        app = new Microsoft.Office.Interop.Excel.Application();
                        wb = app.Workbooks.Add(Nothing);
                        if (wb.Worksheets.Count == 0)
                        {
                            ws = wb.Worksheets.Add();
                            ws.Name = "sheet1";
                        }
                        else
                        {
                            ws = wb.ActiveSheet;
                        }
                        fileName = fn;
                        isavalid = true;
                    }
                }
                else {
                    message = "文件后缀名错误！请从新输入。";
                }
            }
        }
        else
        {
            goto reinput;
        }
    }
    System.Data.SqlClient.SqlConnection conn = new System.Data.SqlClient.SqlConnection();
    conn.ConnectionString = connStr;
    int nowresultset=0;
    try {
        Console.WriteLine("正在尝试打开数据库连接.....");
        System.Data.SqlClient.SqlDataReader reader=null;
        conn.Open();
        try {
            if (parame == null)
                reader = getReader(querystring, conn);
            else
                reader = getReader(querystring, parame, conn);
            Console.WriteLine("数据库连接成功：" + conn.State.ToString() + "....");
            Console.WriteLine("数据读取成功，共获取到{0}列的数据",reader.FieldCount);
        }
        catch (System.Data.SqlClient.SqlException e) { 
            Console.WriteLine("语句执行出错！"+e.Message+"
是否需要查看语句？(输入Y查看)");
            ConsoleKeyInfo ck= Console.ReadKey(true);
            if (ck.Key == ConsoleKey.Y)
            {
                Console.WriteLine(querystring);
                Console.Read();
            }
            throw e;
        }
        do
        {
            FileRule fe=null;
            if(!formatrule.TryGetValue(nowresultset, out fe))
            {
                Console.WriteLine("nowResultset不存在：" + nowresultset.ToString() + "
按任意键继续！");
                Console.Read();
            }
            else {
                Console.WriteLine("nowResultset为：" + fe.Range+"   "+fe.hasTitle.ToString() + "
按任意键继续！");
            }
            if (fe != null)
            {
                Microsoft.Office.Interop.Excel.Range rg;
                if (fe.Range.Contains(":"))
                {
                    rg = ws.get_Range(fe.Range.Split(':')[0], fe.Range.Split(':')[1]);//未初始化？
                }
                else
                {
                    rg = ws.get_Range(fe.Range);
                }
                Console.WriteLine("将按要求写入{0}行{1}列数据。",rg.Row.ToString(),rg.Column.ToString());//
                int colus = rg.Columns.Count,
                    startColu = rg.Column;
                int rows = rg.Rows.Count,
                    startRow = rg.Row;
                int sourceColus = reader.FieldCount;
                int paddingRows = 0;
                Console.WriteLine("开始遍历写入Excel！");
                for (int r = 0; (rows==1&&colus==1)?(reader.Read()):((r < rows) && reader.Read()); r++)
                {
                    for (int c = 0; (rows == 1 && colus == 1) ? c < sourceColus : (c < colus && c < sourceColus); c++)
                    {
                        if (fe.hasTitle == true && r == 0)
                        {
                            if (!fe.allowPivote)
                            {
                                for (int nn = 0; (rows == 1 && colus == 1) ? nn< sourceColus : (nn < colus && c < sourceColus); nn++)
                                {
                                    ws.Cells[startRow+r,startColu+nn]=reader.GetName(nn);
                                }
                            }
                            else
                            {
                                for (int nn = 0; nn < colus; nn++)
                                {
                                    ws.Cells[startColu + nn, startRow + r] = reader.GetName(nn);
                                }
                            }
                            paddingRows = 1;
                        }
                        if (fe.allowPivote)
                        {
                            if (!reader.IsDBNull(c) && reader[c].ToString() != "NULL" && reader[c].ToString() != "")
                            {
                                ws.Cells[startColu + c + paddingRows, startRow + r] = reader[c].ToString();
                            }
                            else
                            {
                                ws.Cells[startColu + c + paddingRows, startRow + r] = "";
                            }
                        }
                        if (!reader.IsDBNull(c) && reader[c].ToString() != "NULL" && reader[c].ToString() != "")//qlNullValueException
                        {
                            ws.Cells[startRow + r + paddingRows, startColu + c] = reader[c].ToString();
                        }
                        else
                        {
                            ws.Cells[startRow + r + paddingRows, startRow + c] = "";
                        }
                    }
                }
            }
            else {
                Console.WriteLine("这个文件并不需要写入！");
            }
            nowresultset++;
        }
        while (reader.NextResult());
        wb.SaveAs(saveTo + @"" + fileName);
        Console.WriteLine("文件创建为：{0}", wb.Path);
        Console.WriteLine("写入结束，任意键继续。");
        Console.ReadKey();
    }
    catch(System.Data.SqlClient.SqlException e){
        Console.WriteLine("数据库打开失败！
是否查看异常信息？（Y继续）");
        ConsoleKeyInfo ki = Console.ReadKey(true);
        if (ki.Key == ConsoleKey.Y) {
            Console.WriteLine("异常信息为：
"+e.Message);
            Console.Read();
        }
    }
    if (app != null) {
        Console.WriteLine("文件创建为：{0}", wb.Path);
        wb.Close();
        app.Quit();
    }
}

private Microsoft.Office.Interop.Excel.Application getAppliction() {
    Microsoft.Office.Interop.Excel.Application app;
    bool flag = false;
    foreach (var item in Process.GetProcesses())
    {
        if (item.ProcessName == "EXCEL")
        {
            flag = true;
            break;
        }
    }
    if (!flag)
    {
        app = new Microsoft.Office.Interop.Excel.Application();
    }
    else
    {
        try
        {
            object obj = System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application");//引用已在在跑的Excel
            app = obj as Microsoft.Office.Interop.Excel.Application;
        }
        catch (Exception e)
        {
            app = new Microsoft.Office.Interop.Excel.Application();
            Debug.WriteLine("发生异常，信息： {0}", "yuanakng", e.Message);
        }
    }
    return app;
}
}

注：自己在里面加了些对自己有用的东西，format文件是自己写的规则，因为通用性不是太好所以不贴出。基础的文件读取写入也不足一提。非常简单的一个小例子。没有用ADO，可控制样式，很灵活。