使用ADO.net将数据导出到Excel并提供下载

public string DataTableToExcel(DataTable dt,string excelPath)

{

if(dt == null)

{

return "DataTable不能为空";

}



int rows = dt.Rows.Count;

int cols = dt.Columns.Count;

StringBuilder sb;

string connString;



if(rows == 0)

{

return "没有数据";

}



sb = new StringBuilder();

connString = string.Format(ConnectionString,excelPath);



//生成创建表的脚本

sb.Append("CREATE TABLE ");

sb.Append(dt.TableName + " ( ");



for(int i=0;i<cols;i++)

{

if(i < cols - 1)

sb.Append(string.Format("{0} varchar,",dt.Columns[i].ColumnName));

else

sb.Append(string.Format("{0} varchar)",dt.Columns[i].ColumnName));

}



using(OleDbConnection objConn = new OleDbConnection(connString))

{

OleDbCommand objCmd = new OleDbCommand();

objCmd.Connection = objConn;



objCmd.CommandText = sb.ToString();



try

{

objConn.Open();

objCmd.ExecuteNonQuery();

}

catch(Exception e)

{

return "在Excel中创建表失败，错误信息：" + e.Message;

}



生成插入数据脚本#region 生成插入数据脚本

sb.Remove(0,sb.Length);

sb.Append("INSERT INTO ");

sb.Append(dt.TableName + " ( ");



for(int i=0;i<cols;i++)

{

if(i < cols - 1)

sb.Append(dt.Columns[i].ColumnName + ",");

else

sb.Append(dt.Columns[i].ColumnName + ") values (");

}



for(int i=0;i<cols;i++)

{

if(i < cols - 1)

sb.Append("@" + dt.Columns[i].ColumnName + ",");

else

sb.Append("@" + dt.Columns[i].ColumnName + ")");

}

#endregion





//建立插入动作的Command

objCmd.CommandText = sb.ToString();

OleDbParameterCollection param = objCmd.Parameters;



for(int i=0;i<cols;i++)

{

param.Add(new OleDbParameter("@" + dt.Columns[i].ColumnName, 
OleDbType.VarChar));

}



//遍历DataTable将数据插入新建的Excel文件中

foreach (DataRow row in dt.Rows)

{ 

for (int i=0; i<param.Count; i++)

{

param[i].Value = row[i]; 

}



objCmd.ExecuteNonQuery();

}



return "数据已成功导入Excel";

}//end using

}