using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.OleDb;
using System.Data.Sql;
using System.Data.SqlClient;
using System.IO;
namespace HPRSP.CommonDataObject
{
public class CSVHelper
{
private string path;
private string fileName;
/// <summary>
/// z构造函数
/// </summary>
public CSVHelper(string filePath, string fileName)
{
this.path = filePath;
this.fileName = fileName;
}
/// <summary>
/// 从Csv中读取数据
/// </summary>
/// <returns></returns>
public DataTable Read()
{
return Read(null);
}
/// <summary>
/// 通过文件流的方式来读取CSV文件，默认第一列为标题列，列之间用逗号分隔
/// </summary>
/// <param name="files"></param>
/// <returns></returns>
public DataTable ReadCsvFileToTable()
{
return ReadCsvFileToTable(true, ',');
}
/// <summary>
/// 通过文件流的方式来读取CSV文件，默认列之间用逗号分隔
/// </summary>
/// <param name="files">文件名称</param>
/// <param name="HeadYes">第一行是否为列标题</param>
/// <returns></returns>
public DataTable ReadCsvFileToTable(bool HeadYes)
{
return ReadCsvFileToTable(HeadYes, ',');
}
/// <summary>
/// 通过文件流的方式来读取CSV文件
/// </summary>
/// <param name="files">文件名称</param>
/// <param name="HeadYes">第一行是否为列标题</param>
/// <param name="span">分隔符</param>
/// <returns></returns>
public DataTable ReadCsvFileToTable(bool HeadYes, char span)
{
//文件路径和文件名
string files = path + fileName;
DataTable dt = new DataTable();
StreamReader fileReader = new StreamReader(files, Encoding.Default);
try
{
//是否为第一行（如果HeadYes为TRUE，则第一行为标题行）
int lsi = 0;
//列之间的分隔符
char cv = span;
while (fileReader.EndOfStream == false)
{
string line = fileReader.ReadLine();
string[] y = line.Split(cv);
//第一行为标题行
if (HeadYes == true)
{
//第一行
if (lsi == 0)
{
for (int i = 0; i < y.Length; i++)
{
dt.Columns.Add(y[i].Trim().ToString());
}
lsi++;
}
//从第二列开始为数据列
else
{
DataRow dr = dt.NewRow();
for (int i = 0; i < y.Length; i++)
{
dr[i] = y[i].Trim();
}
dt.Rows.Add(dr);
}
}
//第一行不为标题行
else
{
if (lsi == 0)
{
for (int i = 0; i < y.Length; i++)
{
dt.Columns.Add("Col" + i.ToString());
}
lsi++;
}
DataRow dr = dt.NewRow();
for (int i = 0; i < y.Length; i++)
{
dr[i] = y[i].Trim();
}
dt.Rows.Add(dr);
}
}
}
catch (Exception ex)
{
throw ex;
}
finally
{
fileReader.Close();
fileReader.Dispose();
}
return dt;
}
/// <summary>
/// 从csv中读取数据
/// </summary>
/// <param name="colNames">列名列表，可为空</param>
/// <returns></returns>
private DataTable Read(string[] colNames)
{
string sql = CreateSql(colNames);
return ExecuteTable(sql);
}
/// <summary>
/// 通过执行sql语句，从Csv中读取数据
/// </summary>
/// <param name="sql">sql语句</param>
/// <returns></returns>
private DataTable ExecuteTable(string sql)
{
DataTable table = new DataTable();
using (OleDbConnection connection = new OleDbConnection(GetConnString(true)))
{
OleDbCommand command = connection.CreateCommand();
command.CommandText = sql;
OleDbDataAdapter adapter = new OleDbDataAdapter(command);
adapter.Fill(table);
}
return table;
}
#region 私有方法
private string CreateSql(string[] colNames)
{
string cols = "*";
if (null != colNames && colNames.Length > 0)
{
StringBuilder colList = new StringBuilder();
for (int i = 0; i < colNames.Length - 1; i++)
{
colList.AppendFormat("[{0}],", colNames[i]);
}
colList.AppendFormat("[{0}]", colList[colList.Length]);
cols = colList.ToString();
}
return string.Format("select {0} from {1}", cols, fileName);
}
private string GetConnString(bool IsHeaderRow)
{
return string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties='Text;FMT=Delimited; HDR={0}';data source={1}", IsHeaderRow ? "Yes" : "No", path);
}
#endregion
}
}