C# CSV文件讀寫

public class CSVFileHelper
{
/// <summary>
/// 將DataTable中數據寫入到CSV文件中
/// </summary>
/// <param name="dt">提供保存數據的DataTable</param>
/// <param name="fileName">CSV的文件路徑</param>
public static void SaveCSV(DataTable dt, string fullPath)
{
FileInfo fi = new FileInfo(fullPath);
if (!fi.Directory.Exists)
{
fi.Directory.Create();
}
FileStream fs = new FileStream(fullPath, System.IO.FileMode.Create, System.IO.FileAccess.Write);
//StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.Default);
StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.UTF8);
string data = "";
//寫出列名稱
for (int i = 0; i < dt.Columns.Count; i++)
{
data += dt.Columns[i].ColumnName.ToString();
if (i < dt.Columns.Count - 1)
{
data += ",";
}
}
sw.WriteLine(data);
//寫出各行數據
for (int i = 0; i < dt.Rows.Count; i++)
{
data = "";
for (int j = 0; j < dt.Columns.Count; j++)
{
string str = dt.Rows[i][j].ToString();
str = str.Replace("\"", "\"\"");//替換英文冒號 英文冒號須要換成兩個冒號
if (str.Contains(',') || str.Contains('"')
|| str.Contains('\r') || str.Contains('\n')) //含逗號 冒號 換行符的須要放到引號中
{
str = string.Format("\"{0}\"", str);
}

data += str;
if (j < dt.Columns.Count - 1)
{
data += ",";
}
}
sw.WriteLine(data);
}
sw.Close();
fs.Close();
DialogResult result = MessageBox.Show("CSV文件保存成功！");
if (result == DialogResult.OK)
{
System.Diagnostics.Process.Start("explorer.exe", Common.PATH_LANG);
}
}

/// <summary>
/// 將CSV文件的數據讀取到DataTable中
/// </summary>
/// <param name="fileName">CSV文件路徑</param>
/// <returns>返回讀取了CSV數據的DataTable</returns>
public static DataTable OpenCSV(string filePath)
{
Encoding encoding = Common.GetType(filePath); //Encoding.ASCII;//
DataTable dt = new DataTable();
FileStream fs = new FileStream(filePath, System.IO.FileMode.Open, System.IO.FileAccess.Read);

//StreamReader sr = new StreamReader(fs, Encoding.UTF8);
StreamReader sr = new StreamReader(fs, encoding);
//string fileContent = sr.ReadToEnd();
//encoding = sr.CurrentEncoding;
//記錄每次讀取的一行記錄
string strLine = "";
//記錄每行記錄中的各字段內容
string[] aryLine = null;
string[] tableHead = null;
//標示列數
int columnCount = 0;
//標示是不是讀取的第一行
bool IsFirst = true;
//逐行讀取CSV中的數據
while ((strLine = sr.ReadLine()) != null)
{
//strLine = Common.ConvertStringUTF8(strLine, encoding);
//strLine = Common.ConvertStringUTF8(strLine);

if (IsFirst == true)
{
tableHead = strLine.Split(',');
IsFirst = false;
columnCount = tableHead.Length;
//建立列
for (int i = 0; i < columnCount; i++)
{
DataColumn dc = new DataColumn(tableHead[i]);
dt.Columns.Add(dc);
}
}
else
{
aryLine = strLine.Split(',');
DataRow dr = dt.NewRow();
for (int j = 0; j < columnCount; j++)
{
dr[j] = aryLine[j];
}
dt.Rows.Add(dr);
}
}
if (aryLine != null && aryLine.Length > 0)
{
dt.DefaultView.Sort = tableHead[0] + " " + "asc";
}

sr.Close();
fs.Close();
return dt;
}
}