C#对excel的操作

本文先描述如何用c#连接、操作excel文件。

项目中需要引入的DLL文件为Interop.Excel、Interop.Microsoft.Office.Core、Interop.Office等。

操作excel前需要定义一些excel变量：

定义操作excel的公共变量[www.cn-web.com]

public Excel.Application m_objExcel = null;//Excel的工作环境

public Excel._Workbook m_objBook = null;//工作簿对象

public Excel.Sheets m_objsheets = null;//工作表集合

public Excel._Worksheet m_objSheet = null;//活动工作表

public Excel.Range m_objRange = null;//选择单元格

连接excel文件并选择要操作的表[www.cn-web.com]

string excelfilename="cn-web-com/1.xls";

excelfilename=Server.MapPath(excelfilename);//取得excel文件的地址

m_objExcel = new Excel.Application();

m_objBook = m_objExcel.Workbooks.Open(excelfilename, m_objOpt, m_objOpt, m_objOpt, m_objOpt, m_objOpt, m_objOpt, m_objOpt, m_objOpt, m_objOpt, m_objOpt, m_objOpt, m_objOpt);

m_objsheets=m_objBook.Worksheets;

m_objSheet=(_Worksheet)m_objsheets.get_Item(1);//选择的是第一个表

经过以上操作，我们可以连接上了excel并获取excel里第一张表的对象：m_objSheet。

连接上后，我们向excel表里写入数据：

向excel某单元格内写入数据[www.cn-web.com]

string pos="A1";//excel中A1的位置。

m_objRange = m_objSheet.get_Range(_pos, m_objOpt);//取得单元格

m_objRange.Value2 = "技术支持：cn-web.com(老韩)";//向A1单元格中写入数据

接着，我们将此excel另存：

保存excel文档[www.cn-web.com]

m_objBook.SaveAs(savefileurl, oP.m_objOpt, oP.m_objOpt, oP.m_objOpt, oP.m_objOpt, oP.m_objOpt, Excel.XlSaveAsAccessMode.xlShared, oP.m_objOpt, oP.m_objOpt, oP.m_objOpt, oP.m_objOpt);//savefileurl为物理地址

最后，要记着关闭excel进程：

关闭excel操作进程[www.cn-web.com]

m_objBook.Close(m_objOpt, m_objOpt, m_objOpt);

m_objExcel.Workbooks.Close();

m_objExcel.Quit();

System.Runtime.InteropServices.Marshal.ReleaseComObject(m_objBook);

System.Runtime.InteropServices.Marshal.ReleaseComObject(m_objExcel);

m_objBook = null;

m_objExcel = null;

GC.Collect();

foreach (System.Diagnostics.Process p in System.Diagnostics.Process.GetProcesses())

{

if (p.ProcessName.ToUpper() == "EXCEL")

{

p.Kill();

}

}

Asp.Net下导出/导入规则的Excel(.xls)文件

datatable中的数据导出excel文件

/// <summary>

/// 将datatable中的数据导出到指定的excel文件中

/// </summary>

/// <param name="page">web页面对象</param>

/// <param name="tab">包含被导出数据的datatable对象</param>

/// <param name="filename">excel文件的名称</param>

public static void export(system.web.ui.page page,system.data.datatable tab,string filename)

{

system.web.httpresponse httpresponse = page.response;

system.web.ui.webcontrols.datagrid datagrid=new system.web.ui.webcontrols.datagrid();

datagrid.datasource=tab.defaultview;

datagrid.allowpaging = false;

datagrid.headerstyle.backcolor = system.drawing.color.green;

datagrid.headerstyle.horizontalalign = horizontalalign.center;

datagrid.headerstyle.font.bold = true;

datagrid.databind();

httpresponse.appendheader("content-disposition","attachment;filename="+httputility.urlencode(filename,system.text.encoding.utf8)); //filename="*.xls";

httpresponse.contentencoding=system.text.encoding.getencoding("gb2312");

httpresponse.contenttype ="application/ms-excel";

system.io.stringwriter tw = new system.io.stringwriter() ;

system.web.ui.htmltextwriter hw = new system.web.ui.htmltextwriter (tw);

datagrid.rendercontrol(hw);

string filepath = page.server.mappath("..")+"\\files\\" +filename;

system.io.streamwriter sw = system.io.file.createtext(filepath);

sw.write(tw.tostring());

sw.close();

downfile(httpresponse,filename,filepath);

httpresponse.end();

}

private static bool downfile(system.web.httpresponse response,string filename,string fullpath)

{

try

{

response.contenttype = "application/octet-stream";

response.appendheader("content-disposition","attachment;filename=" +

httputility.urlencode(filename,system.text.encoding.utf8) + ";charset=gb2312");

system.io.filestream fs= system.io.file.openread(fullpath);

long flen=fs.length;

int size=102400;//每100k同时下载数据

byte[] readdata = new byte[size];//指定缓冲区的大小

if(size>flen)size=convert.toint32(flen);

long fpos=0;

bool isend=false;

while (!isend)

{

if((fpos+size)>flen)

{

size=convert.toint32(flen-fpos);

readdata = new byte[size];

isend=true;

}

fs.read(readdata, 0, size);//读入一个压缩块

response.binarywrite(readdata);

fpos+=size;

}

fs.close();

system.io.file.delete(fullpath);

return true;

}

catch

{

return false;

}

}

将指定excel文件中的数据转换成datatable

/// <summary>

/// 将指定excel文件中的数据转换成datatable对象，供应用程序进一步处理

/// </summary>

/// <param name="filepath"></param>

/// <returns></returns>

public static system.data.datatable import(string filepath)

{

system.data.datatable rs = new system.data.datatable();

bool canopen=false;

oledbconnection conn = new oledbconnection("provider=microsoft.jet.oledb.4.0;"+

"data source=" + filepath + ";" +

"extended properties=\"excel 8.0;\"");

try//尝试数据连接是否可用

{

conn.open();

conn.close();

canopen=true;

}

catch{}

if(canopen)

{

try//如果数据连接可以打开则尝试读入数据

{

oledbcommand myoledbcommand = new oledbcommand("select * from [sheet1$]",conn);

oledbdataadapter mydata = new oledbdataadapter(myoledbcommand);

mydata.fill(rs);

conn.close();

}

catch//如果数据连接可以打开但是读入数据失败，则从文件中提取出工作表的名称，再读入数据

{

string sheetname=getsheetname(filepath);

if(sheetname.length>0)

{

oledbcommand myoledbcommand = new oledbcommand("select * from ["+sheetname+"$]",conn);

oledbdataadapter mydata = new oledbdataadapter(myoledbcommand);

mydata.fill(rs);

conn.close();

}

}

}

else

{

system.io.streamreader tmpstream=file.opentext(filepath);

string tmpstr=tmpstream.readtoend();

tmpstream.close();

rs=getdatatablefromstring(tmpstr);

tmpstr="";

}

return rs;

}

/// <summary>

/// 将指定html字符串的数据转换成datatable对象 --根据“<tr><td>”等特殊字符进行处理

/// </summary>

/// <param name="tmphtml">html字符串</param>

/// <returns></returns>

private static datatable getdatatablefromstring(string tmphtml)

{

string tmpstr=tmphtml;

datatable tb=new datatable();

//先处理一下这个字符串，删除第一个<tr>之前合最后一个</tr>之后的部分

int index=tmpstr.indexof("<tr");

if(index>-1)

tmpstr=tmpstr.substring(index);

else

return tb;

index=tmpstr.lastindexof("</tr>");

if(index>-1)

tmpstr=tmpstr.substring(0,index+5);

else

return tb;

bool existssparator=false;

char separator=convert.tochar("^");

//如果原字符串中包含分隔符“^”则先把它替换掉

if(tmpstr.indexof(separator.tostring())>-1)

{

existssparator=true;

tmpstr=tmpstr.replace("^","^$&^");

}

//先根据“</tr>”分拆

string[] tmprow=tmpstr.replace("</tr>","^").split(separator);

for(int i=0;i<tmprow.length-1;i++)

{

datarow newrow=tb.newrow();

string tmpstri=tmprow[i];

if(tmpstri.indexof("<tr")>-1)

{

tmpstri=tmpstri.substring(tmpstri.indexof("<tr"));

if(tmpstri.indexof("display:none")<0||tmpstri.indexof("display:none")>tmpstri.indexof(">"))

{

tmpstri=tmpstri.replace("</td>","^");

string[] tmpfield=tmpstri.split(separator);

for(int j=0;j<tmpfield.length-1;j++)

{

tmpfield[j]=removestring(tmpfield[j],"<font>");

index=tmpfield[j].lastindexof(">")+1;

if(index>0)

{

string field=tmpfield[j].substring(index,tmpfield[j].length-index);

if(existssparator) field=field.replace("^$&^","^");

if(i==0)

{

string tmpfieldname=field;

int sn=1;

while(tb.columns.contains(tmpfieldname))

{

tmpfieldname=field+sn.tostring();

sn+=1;

}

tb.columns.add(tmpfieldname);

}

else

{

newrow[j]=field;

}

}//end of if(index>0)

}

if(i>0)

tb.rows.add(newrow);

}

}

}

tb.acceptchanges();

return tb;

}

/// <summary>

/// 从指定html字符串中剔除指定的对象

/// </summary>

/// <param name="tmphtml">html字符串</param>

/// <param name="remove">需要剔除的对象--例如输入"<font>"则剔除"<font ???????>"和"</font>>"</param>

/// <returns></returns>

public static string removestring(string tmphtml,string remove)

{

tmphtml=tmphtml.replace(remove.replace("<","</"),"");

tmphtml=removestringhead(tmphtml,remove);

return tmphtml;

}

/// <summary>

/// 只供方法removestring()使用

/// </summary>

/// <returns></returns>

private static string removestringhead(string tmphtml,string remove)

{

//为了方便注释，假设输入参数remove="<font>"

if(remove.length<1) return tmphtml;//参数remove为空：不处理返回

if((remove.substring(0,1)!="<")||(remove.substring(remove.length-1)!=">")) return tmphtml;//参数remove不是<?????>：不处理返回

int indexs=tmphtml.indexof(remove.replace(">",""));//查找“<font”的位置

int indexe=-1;

if(indexs>-1)

{

string tmpright=tmphtml.substring(indexs,tmphtml.length-indexs);

indexe=tmpright.indexof(">");

if(indexe>-1)

tmphtml=tmphtml.substring(0,indexs)+tmphtml.substring(indexs+indexe+1);

if(tmphtml.indexof(remove.replace(">",""))>-1)

tmphtml=removestringhead(tmphtml,remove);

}

return tmphtml;

}

/// <summary>

/// 将指定excel文件中读取第一张工作表的名称

/// </summary>

/// <param name="filepath"></param>

/// <returns></returns>

private static string getsheetname(string filepath)

{

string sheetname="";

system.io.filestream tmpstream=file.openread(filepath);

byte[] filebyte=new byte[tmpstream.length];

tmpstream.read(filebyte,0,filebyte.length);

tmpstream.close();

byte[] tmpbyte=new byte[]{convert.tobyte(11),convert.tobyte(0),convert.tobyte(0),convert.tobyte(0),convert.tobyte(0),convert.tobyte(0),convert.tobyte(0),convert.tobyte(0),

convert.tobyte(11),convert.tobyte(0),convert.tobyte(0),convert.tobyte(0),convert.tobyte(0),convert.tobyte(0),convert.tobyte(0),convert.tobyte(0),

convert.tobyte(30),convert.tobyte(16),convert.tobyte(0),convert.tobyte(0)};

int index=getsheetindex(filebyte,tmpbyte);

if(index>-1)

{

index+=16+12;

system.collections.arraylist sheetnamelist=new system.collections.arraylist();

for(int i=index;i<filebyte.length-1;i++)

{

byte temp=filebyte[i];

if(temp!=convert.tobyte(0))

sheetnamelist.add(temp);

else

break;

}

byte[] sheetnamebyte=new byte[sheetnamelist.count];

for(int i=0;i<sheetnamelist.count;i++)

sheetnamebyte[i]=convert.tobyte(sheetnamelist[i]);

sheetname=system.text.encoding.default.getstring(sheetnamebyte);

}

return sheetname;

}

/// <summary>

/// 只供方法getsheetname()使用

/// </summary>

/// <returns></returns>

private static int getsheetindex(byte[] findtarget,byte[] finditem)

{

int index=-1;

int finditemlength=finditem.length;

if(finditemlength<1) return -1;

int findtargetlength=findtarget.length;

if((findtargetlength-1)<finditemlength) return -1;

for(int i=findtargetlength-finditemlength-1;i>-1;i--)

{

system.collections.arraylist tmplist=new system.collections.arraylist();

int find=0;

for(int j=0;j<finditemlength;j++)

{

if(findtarget[i+j]==finditem[j]) find+=1;

}

if(find==finditemlength)

{

index=i;

break;

}

}

return index;

}