C#读写Excel文件（三）
通过逐行逐个单元格向Excel写入数据的方式比较慢，下面介绍通过OLEDB方式向excel批量写入数据，速度可以提高很多倍。
使用OLEDB方式写入数据到excel表格
【方法一】
///
/// 使用oledb快速写入数据到excel
///
///
///
static public void FastWriteToExcel2(DataTable data,string newFileName)
{
/*
* 注意：使用该方法，要求如下：
* （1）将IMEX值设置为0
* （2）excel文件newFileName已经存在
* （3）excel文件的Sheet1中的第一行必须存在于dt一致的列名及顺序
*/
string oledbString = string.Empty;
string tmstr = "Extended Properties='Excel 8.0;HDR=YES;IMEX=0;'";
try
{
oledbString = System.Configuration.ConfigurationManager.AppSettings["oledbString"].ToString();
tmstr = System.Configuration.ConfigurationManager.AppSettings["ExtendedString"].ToString();
}
catch (Exception e)
{
throw e;
}
//string newFileName = xlsFilePath + "导出的excel文件.xlsx";
// string newFileName = xlsFilePath + "导出的excel文件" + DateTime.Now.ToString("yyyyMMddHHmmss") + ".xls";
string cnnStr = string.Format(oledbString + "Data Source='{0}';" +
tmstr, newFileName);
string sql = "SELECT * FROM [Sheet1$]";
using(OleDbConnection myConn=new OleDbConnection(cnnStr))
{
myConn.Open();
OleDbDataAdapter myDataAdapter = new OleDbDataAdapter(sql, myConn);
DataSet myDataSet = new DataSet();
myDataAdapter.Fill(myDataSet, "[Sheet1$]");
myConn.Close();
DataTable dt = myDataSet.Tables[0]; //初始化DataTable实例
dt.PrimaryKey = new DataColumn[] { dt.Columns["ID"] };//创建索引列
int rowNum = data.Rows.Count;
int colNum = data.Columns.Count;
for (int k = 0; k < rowNum; k++)
{
DataRow myRow = dt.NewRow();
for (int m = 0; m < colNum; m++) myRow[m] = data.Rows[k][m];
dt.Rows.Add(myRow);
}
OleDbCommandBuilder odcb = new OleDbCommandBuilder(myDataAdapter);
odcb.QuotePrefix = "[";
odcb.QuoteSuffix = "]";
myDataAdapter.Update(myDataSet, "[Sheet1$]"); //更新数据集对应的表
}
}
【方法二】
///
/// 使用oledb快速写入数据到excel
///
/// 数据
/// 文件名
static public void FastWriteToExcel(DataTable dt, string newFileName)
{
/*
* 注意：使用该方法，要求如下：
* （1）将IMEX值设置为0
* （2）excel文件newFileName已经存在
* （3）excel文件的Sheet1中的第一行必须存在于dt一致的列名及顺序
*/
string oledbString = string.Empty;
string tmstr = "Extended Properties='Excel 8.0;HDR=YES;IMEX=0;'";
try
{
oledbString = System.Configuration.ConfigurationManager.AppSettings["oledbString"].ToString();
tmstr = System.Configuration.ConfigurationManager.AppSettings["ExtendedString"].ToString();
}
catch (Exception e)
{
throw e;
}
//string newFileName = xlsFilePath + "导出的excel文件.xlsx";
// string newFileName = xlsFilePath + "导出的excel文件" + DateTime.Now.ToString("yyyyMMddHHmmss") + ".xls";
string strCon = string.Format(oledbString + "Data Source='{0}';" +
tmstr, newFileName);
OleDbConnection oldCon = null;
try
{
oldCon = new OleDbConnection(strCon);
oldCon.Open();
string sqlCreateSheet=string.Empty;
using (OleDbCommand cmd=oldCon.CreateCommand())
{
//sqlCreateSheet = string.Format("CREATE TABLE {0} (", ds.Tables[0].TableName);
string header = string.Empty;
for (int col = 0; col < dt.Columns.Count; col++)
{
header += dt.Columns[col].Caption + ",";
//sqlCreateSheet += string.Format("[{0}] VarChar,", ds.Tables[i].Columns[col].Caption);
}
header = header.Substring(0, header.Length - 1);
//sqlCreateSheet += sqlCreateSheet.Substring(0, sqlCreateSheet.Length - 1) + ")";
//cmd.CommandText = sqlCreateSheet;
//cmd.ExecuteNonQuery();//创建表
for (int row_index = 0; row_index < dt.Rows.Count; row_index++)
{
string sql = string.Format("insert into [Sheet1$]({0}) values(",header,dt.TableName);
for (int col_index = 0; col_index < dt.Columns.Count; col_index++)
{
sql += string.Format("'{0}',", dt.Rows[row_index][col_index].ToString());
}
sql = sql.Substring(0, sql.Length - 1) + ");";
cmd.CommandText = sql;
cmd.ExecuteNonQuery();
}
}
}
catch (Exception e)
{
throw e;
}
finally
{
oldCon.Close();
}
}