C#变成数据导入Excel和导出Excel

Posted 2020-06-17

excel 基础

•整个excel 表格叫工作表：workbook；工作表包含的叫页：sheet；行：row；单元格：cell。

•excel 中的电话号码问题，看起来像数字的字符串以半角单引号开头就没问题了。

•使用区域（usedrange）：用excel 表的时候不一定是从最左上角的单元格开始用，为了减小文件尺寸，有使用区域的概念，excel 只存储使用区域。

程序处理excel 的技术

•ole automation：程序启动一个excel 进程，然后和excel 进程进行通讯来进行excel 的操作。优点：强大，能够使用excel 的所有功能，要求装excel ，微软最推荐这种用法，因为可以促进excel 的销量。会启动excel 进程，不适合于服务器（比如asp.net网站，安全性、效率）。参考资料http://www.makaidong.com/denylau/archive/2010/04/30/1725172.html 

–演示一下，引用excel .interop，代码在备注

applicationclass c = new applicationclass();
            c.visible = false;
            workbook wb = c.workbooks.add(xlwbatemplate.xlwbatworksheet);
            //wb.saveas("c:/1.xls", null, null, null, null, xlsaveasaccessmode.xlnochange, xlsaveasaccessmode.xlnochange, null, null, null, null, null);

•(*)把excel 当成其他数据库 ，使用microsoft.jet.oledb访问访问excel ，参考资料 http://tieba.baidu.com/f?kz=331569890 只适合于完全二维结构，功能最弱，很少用。不用装excel 。

•(*) openxml，微软提供的读写excel 的技术，优点和npoi差不多，不过只能处理xlsx格式文件。docx、pptx

•npoi、myxls等，npoi能够分析excel 文件的格式，能够进行常用excel 操作，不依赖于excel ，节省资源，没有安全性、性能的问题，在asp.net中用最合适。只能处理xls格式文件、不能处理xlsx这样的新版本excel 文件格式。

 

                                                                                              npoi组件的引入

•我们平时调用的类是已经添加到引用的，如果想调用系统内置的没有添加引用的其他dll（*严格的说是在gac中的assembly）就要添加引用，在【.net】选项卡中选择，对于另外一些第三方dll（*严格说是assembly）则需要点击【浏览】选项卡选择对应的dll文件。

•将npoi包解压到硬盘中，然后在项目中添加引用，浏览，将解压目录下的dll全部添加进来

•(*)poi是apache的一个java开源项目，npoi是poi在.net下的移植版本，很多.net的移植版本开源项目都是在原来的java版本名称前加上n，比如nhibernate 、ndoc、nunit、nant。

                                                                                                 npoi起步

1、读取

 using (filestream stream = new filestream(@"c:\客户资料.xls", filemode.open, fileaccess.read))

            {

                hssfworkbook workbook = new hssfworkbook(stream);

                messagebox.show(workbook.getsheetname(0));

            }

2、遇到错误别慌，仔细看错误信息。可能遇到

 

 

此文来自: 马开东博客 转载请注明出处 网址： http://www.makaidong.com

的问题：文件被其他进程占用。

 

3、npoi处理wps生成的xls有问题。

                                                                                                       读取excel

 private void button1_click(object sender, eventargs e)
        {
            //using (filestream stream = new filestream(@"c:\book1.xls", filemode.open, fileaccess.read))
            //{
            //    hssfworkbook workbook = new hssfworkbook(stream);
            //    messagebox.show(workbook.getsheetname(0));
            //}

            //using (filestream stream = new filestream(@"c:\book1.xls", filemode.open, fileaccess.read))
            //{
            //    hssfworkbook workbook = new hssfworkbook(stream);
            //    hssfsheet sheet = workbook.getsheetat(0);
            //    hssfrow row = sheet.getrow(0);
            //    hssfcell cell1 = row.getcell(1);
            //    hssfcell cell0 = row.getcell(0);
                
            //    messagebox.show(cell1.numericcellvalue.tostring());
            //    messagebox.show(cell0.stringcellvalue.tostring());
            //}

            //using (filestream stream = new filestream(@"c:\book1.xls", filemode.open, fileaccess.read))
            //{
            //    hssfworkbook workbook = new hssfworkbook(stream);
            //    hssfsheet sheet = workbook.getsheetat(0);
            //    hssfrow row = sheet.getrow(0);
            //    hssfcell cell1 = row.getcell(1);
            //    if (cell1.celltype == hssfcell.cell_type_string)
            //    {
            //        messagebox.show("字符串");
            //    }
            //    else if (cell1.celltype == hssfcell.cell_type_numeric)
            //    {
            //        messagebox.show("数字");
            //    }
            //}

            using (filestream stream = new filestream(@"c:\book1.xls", filemode.open, fileaccess.read))
            {
                hssfworkbook workbook = new hssfworkbook(stream);
                hssfsheet sheet = workbook.getsheetat(0);
                for (int i = 0; i <= sheet.lastrownum; i++)
                {
                    hssfrow row = sheet.getrow(i);
                    hssfcell cell0 = row.getcell(0);
                    hssfcell cell1 = row.getcell(1);
                    messagebox.show(string.format("{0}的年龄是：{1}",cell0.stringcellvalue,cell1.numericcellvalue));
                    
                }
                //messagebox.show(sheet.lastrownum.tostring());
            }

        }

•读取字符串类型数据messagebox.show(sheet.getrow(3).getcell(4).stringcellvalue); 读取数字类型数据numericcellvalue。

•判断单元格数据类型：读取getcell(4).celltype，与hssfcell类中定义的常量比较即可。

•判断使用区域：结束行号：lastrownum

using system;
using system.collections.generic;
using system.componentmodel;
using system.data;
using system.drawing;
using system.linq;
using system.text;
using system.windows.forms;
using system.io;
using npoi.hssf.usermodel;
using callcenterclient.dal;
using system.data.sqlclient;

namespace callcenterclient.customers
{
    public partial class formcustmgr : form
    {
        public formcustmgr()
        {
            initializecomponent();
        }

        private void btnimportexcel _click(object sender, eventargs e)
        {
            //string filename = @"c:\khzl.xls";
            string filename = txtfilename.text;//界面上敲的是什么就是什么，没有转义，转义是给编译器看的

            try
            {
                using (filestream stream = new filestream(filename, filemode.open, fileaccess.read))
                {
                    hssfworkbook workbook = new hssfworkbook(stream);
                    hssfsheet sheet = workbook.getsheetat(0);
                    for (int i = 1; i <= sheet.lastrownum; i++)//注意从第1行开始读，第一行是表头
                    {
                        hssfrow row = sheet.getrow(i);
                        hssfcell cellname = row.getcell(0);
                        hssfcell celltel = row.getcell(1);
                        hssfcell cellbuydate = row.getcell(2);
                        hssfcell cellcarno = row.getcell(3);
                        hssfcell cellbrno = row.getcell(4);

                        //sqlhelper.executenonquery("insert into t_customers(id,name,telphone,buydate,carnum,bracketnum) values(newid(),@name,@telphone,@buydate,@carnum,@bracketnum)",
                        //    new sqlparameter("name", cellname.stringcellvalue),
                        //    new sqlparameter("telphone", celltel.stringcellvalue),
                        //    new sqlparameter("buydate", cellbuydate.datecellvalue),
                        //    new sqlparameter("carnum", cellcarno.stringcellvalue),
                        //    new sqlparameter("bracketnum", cellbrno.stringcellvalue));//newid()写在sql语句综合 中，在c#看来就是普通字符串，把sql扔给sqlserver运行，sqlserver会识别这个函数



                        //sqlhelper.executenonquery("insert into t_customers(id,name,telphone,buydate,carnum,bracketnum) values(" + newid() + ",@name,@telphone,@buydate,@carnum,@bracketnum)");//错误，注意区别。

                        sqlhelper.executenonquery("insert into t_customers(id,name,telphone,buydate,carnum,bracketnum) values(newid(),@name,@telphone,@buydate,@carnum,@bracketnum)",
                            new sqlparameter("name", cellname.stringcellvalue),//易错：别写成new sqlparameter("name", cellname)
                            new sqlparameter("telphone", celltel.stringcellvalue),
                            new sqlparameter("buydate", cellbuydate.datecellvalue),
                            new sqlparameter("carnum", cellcarno.stringcellvalue),
                            new sqlparameter("bracketnum", cellbrno.stringcellvalue));

                    }
                }
                messagebox.show("导入成功！");
            }
            catch (ioexception ex)//抓住ioexception类型的异常（文件正在被打开等异常）
            {
                messagebox.show(ex.message);
            }
        }

        private void btnimportexcel 2_click(object sender, eventargs e)
        {
            string filename = txtfilename.text;//界面上敲的是什么就是什么，没有转义，转义是给编译器看的

            try
            {
                using (filestream stream = new filestream(filename, filemode.open, fileaccess.read))
                {
                    hssfworkbook workbook = new hssfworkbook(stream);
                    hssfsheet sheet = workbook.getsheetat(0);
                    for (int i = 1; i <= sheet.lastrownum; i++)//注意从第1行开始读，第一行是表头
                    {
                        hssfrow row = sheet.getrow(i);
                        hssfcell cellname = row.getcell(0);
                        hssfcell celltel = row.getcell(1);
                        hssfcell cellbuydate = row.getcell(2);
                        hssfcell cellcarno = row.getcell(3);
                        hssfcell cellbrno = row.getcell(4);

                        //正确写法
                        int count = (int)sqlhelper.executescalar("select count(*) from t_customers where [email protected] or [email protected]", new sqlparameter("carnum", cellcarno.stringcellvalue),
                            new sqlparameter("bracketnum", cellbrno.stringcellvalue));
                        //是否其他数据库 中有这辆车
                        if (count > 0)
                        {
                            continue;
                        }
                        datetime buydate;
                        if (cellbuydate.celltype == hssfcell.cell_type_numeric)//日期类型
                        {
                            buydate = cellbuydate.datecellvalue;
                        }
                        else if (cellbuydate.celltype == hssfcell.cell_type_string)//2008年9月8号
                        {
                            string strbuydate = cellbuydate.stringcellvalue;
                            strbuydate = strbuydate.replace("号", "日");
                            buydate = convert.todatetime(strbuydate);
                        }
                        else
                        {
                            throw new exception("未知的购买日期单元格类型");
                        }

                        sqlhelper.executenonquery("insert into t_customers(id,name,telphone,buydate,carnum,bracketnum) values(newid(),@name,@telphone,@buydate,@carnum,@bracketnum)",
                            new sqlparameter("name", cellname.stringcellvalue),//易错：别写成new sqlparameter("name", cellname)
                            new sqlparameter("telphone", celltel.stringcellvalue),
                            new sqlparameter("buydate", buydate),
                            new sqlparameter("carnum", cellcarno.stringcellvalue),
                            new sqlparameter("bracketnum", cellbrno.stringcellvalue));



                        //错误写法：一个sqlparameter只能被一个command使用，只能添加一次
                        //sqlparameter pcarnum = new sqlparameter("carnum", cellcarno.stringcellvalue);

                        //int count = (int)sqlhelper.executescalar("select count(*) from t_customers where [email protected] or [email protected]", pcarnum,
                        //    new sqlparameter("bracketnum", cellbrno.stringcellvalue));
                        ////是否其他数据库 中有这辆车
                        //if (count > 0)
                        //{
                        //    continue;
                        //}

                        //sqlhelper.executenonquery("insert into t_customers(id,name,telphone,buydate,carnum,bracketnum) values(newid(),@name,@telphone,@buydate,@carnum,@bracketnum)",
                        //    new sqlparameter("name", cellname.stringcellvalue),//易错：别写成new sqlparameter("name", cellname)
                        //    new sqlparameter("telphone", celltel.stringcellvalue),
                        //    new sqlparameter("buydate", cellbuydate.datecellvalue),
                        //    pcarnum,
                        //    new sqlparameter("bracketnum", cellbrno.stringcellvalue));

                        //影响的行数指的是修改了(update、delete等)的数据的行数，而不是select结果集的行数
                        //int count =sqlhelper.executenonquery("select * from t_customers where [email protected] or [email protected]",new sqlparameter("carnum",cellcarno.stringcellvalue),
                        //    new sqlparameter("bracketnum", cellbrno.stringcellvalue));
                        ////是否其他数据库 中有这辆车
                        //if (count > 0)
                        //{
                        //    continue;
                        //}

                        //sqlhelper.executenonquery("insert into t_customers(id,name,telphone,buydate,carnum,bracketnum) values(newid(),@name,@telphone,@buydate,@carnum,@bracketnum)",
                        //    new sqlparameter("name", cellname.stringcellvalue),//易错：别写成new sqlparameter("name", cellname)
                        //    new sqlparameter("telphone", celltel.stringcellvalue),
                        //    new sqlparameter("buydate", cellbuydate.datecellvalue),
                        //    new sqlparameter("carnum", cellcarno.stringcellvalue),
                        //    new sqlparameter("bracketnum", cellbrno.stringcellvalue));

                    }
                }
                messagebox.show("导入成功！");
            }
            catch (ioexception ex)//抓住ioexception类型的异常（文件正在被打开等异常）
            {
                messagebox.show(ex.message);
            }
        }

        private void button1_click(object sender, eventargs e)
        {           

            try
            {
                importexcel 3();
                messagebox.show("导入成功！");
            }
            catch (ioexception ex)//抓住ioexception类型的异常（文件正在被打开等异常）
            {
                messagebox.show(ex.message);
            }
        }

        private void importexcel 3()
        {
            string filename = txtfilename.text;//界面上敲的是什么就是什么，没有转义，转义是给编译器看的
            using (filestream stream = new filestream(filename, filemode.open, fileaccess.read))
            {
                hssfworkbook workbook = new hssfworkbook(stream);
                hssfsheet sheet = workbook.getsheetat(0);
                using (sqlconnection conn = new sqlconnection(sqlhelper.connstr))
                {
                    conn.open();
                    for (int i = 1; i <= sheet.lastrownum; i++)//注意从第1行开始读，第一行是表头
                    {
                        hssfrow row = sheet.getrow(i);
                        hssfcell cellname = row.getcell(0);
                        hssfcell celltel = row.getcell(1);
                        hssfcell cellbuydate = row.getcell(2);
                        hssfcell cellcarno = row.getcell(3);
                        hssfcell cellbrno = row.getcell(4);

                        //正确写法
                        int count = (int)sqlhelper.executescalar(conn,"select count(*) from t_customers where [email protected] or [email protected]", new sqlparameter("carnum", cellcarno.stringcellvalue),
                            new sqlparameter("bracketnum", cellbrno.stringcellvalue));
                        //是否其他数据库 中有这辆车
                        if (count > 0)
                        {
                            continue;
                        }
                        datetime buydate;
                        if (cellbuydate.celltype == hssfcell.cell_type_numeric)//日期类型
                        {
                            buydate = cellbuydate.datecellvalue;
                        }
                        else if (cellbuydate.celltype == hssfcell.cell_type_string)//2008年9月8号
                        {
                            string strbuydate = cellbuydate.stringcellvalue;
                            strbuydate = strbuydate.replace("号", "日");
                            buydate = convert.todatetime(strbuydate);
                        }
                        else
                        {
                            throw new exception("未知的购买日期单元格类型");
                        }

                        sqlhelper.executenonquery(conn, "insert into t_customers(id,name,telphone,buydate,carnum,bracketnum) values(newid(),@name,@telphone,@buydate,@carnum,@bracketnum)",
                            new sqlparameter("name", cellname.stringcellvalue),//易错：别写成new sqlparameter("name", cellname)
                            new sqlparameter("telphone", celltel.stringcellvalue),
                            new sqlparameter("buydate", buydate),
                            new sqlparameter("carnum", cellcarno.stringcellvalue),
                            new sqlparameter("bracketnum", cellbrno.stringcellvalue));

                    }
                }
                
            }
        }

        private void btnexporttoexcel 1_click(object sender, eventargs e)
        {
            if (savefiledlg.showdialog() != dialogresult.ok)
            {
                return;
            }
            hssfworkbook workbook = new hssfworkbook();
            hssfsheet sheet = workbook.createsheet();
            //姓名    电话    购买日期    车号    车架号
            //别用dataset，因为数据量可能会非常大，如果用dataset会非常占内存。
            
            using (sqlconnection conn = new sqlconnection(sqlhelper.connstr))
            {
                conn.open();
                using (sqlcommand cmd = conn.createcommand())
                {
                    cmd.commandtext = "select * from t_customers";
                    using (sqldatareader reader = cmd.executereader())
                    {   //todo:加表头。
                        int rownum = 0;//行号
                        while (reader.read())
                        {
                            string name = reader.getstring(reader.getordinal("name"));
                            string telphone = reader.getstring(reader.getordinal("telphone"));
                            datetime buydate = reader.getdatetime(reader.getordinal("buydate"));
                            string carnum = reader.getstring(reader.getordinal("carnum"));
                            string brnum = reader.getstring(reader.getordinal("bracketnum"));

                            hssfrow row = sheet.createrow(rownum);//创建第rownum行

                            row.createcell(0, hssfcell.cell_type_string).setcellvalue(name);
                            row.createcell(1, hssfcell.cell_type_string).setcellvalue(telphone);
                            row.createcell(2, hssfcell.cell_type_string).setcellvalue(buydate.toshortdatestring());
                            row.createcell(3, hssfcell.cell_type_string).setcellvalue(carnum);
                            row.createcell(4, hssfcell.cell_type_string).setcellvalue(brnum);
                            rownum++;
                        }
                    }
                }
            }



            using (filestream stream = new filestream(savefiledlg.filename, filemode.openorcreate, fileaccess.readwr ite))
            {
                workbook.write(stream);
            }
            messagebox.show("保存成功！");

        }

        private void formcustmgr_load(object sender, eventargs e)
        {
            this.t_customerstableadapter1.fill(this.datasetcustomers1.t_customers);
        }

        private void btnaddnew_click(object sender, eventargs e)
        {
            datarowview drv = bscustomers.addnew() as datarowview;
            callcenterclient.dal.datasetcustomers.t_customersrow custrow = drv.row as callcenterclient.dal.datasetcustomers.t_customersrow;
            custrow.id = guid.newguid();
        }

        private void btnsave_click(object sender, eventargs e)
        {
            t_customerstableadapter1.update(this.datasetcustomers1.t_customers);
        }
    }
} mmmm写入excel 

 hssfworkbook workbook = new hssfworkbook();
            hssfsheet sheet = workbook.createsheet();
            hssfrow row = sheet.createrow(0);
            row.createcell(0, hssfcell.cell_type_string).setcellvalue("hello");
            row.createcell(1, hssfcell.cell_type_numeric).setcellvalue(3.14);
            using (filestream stream = new filestream(@"c:\1.xls", filemode.openorcreate, fileaccess.readwr ite))
            {
                workbook.write(stream);
            }

 

 

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