DataTable to CSV and CSV to DataTable

1、將DataTable內容寫入到CSV文件

        /// <summary>
        /// 將DataTable中的數據保存成CSV文件
        /// </summary>
        private void btnSaveCSV_Click(object sender, EventArgs e)
        {
            saveFileDialog1.Filter = "CSV文件|*.CSV";
            saveFileDialog1.InitialDirectory = "C:\\";
            if (saveFileDialog1.ShowDialog() == DialogResult.Cancel)
            {
                return;
            }
            else
            {
                string fileName = saveFileDialog1.FileName;
                SaveCSV(ds.Tables[0], fileName);
            }
        }

 

        /// <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 void SaveCSV(DataTable dt, string fileName)
        {
            FileStream fs = new FileStream(fileName, System.IO.FileMode.Create, System.IO.FileAccess.Write);
            StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.Default);
            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++)
                {
                    data += dt.Rows[i][j].ToString();
                    if (j < dt.Columns.Count - 1)
                    {
                        data += ",";
                    }
                }
                sw.WriteLine(data);
            }

            sw.Close();
            fs.Close();
            MessageBox.Show("CSV文件保存成功！");
        }

 

 

2、將CSV文件內容讀取到DataTable中

        /// <summary>
        /// 打開CSV並顯示其數據
        /// </summary>
        private void btnOpenCSV_Click(object sender, EventArgs e)
        {
            openFileDialog1.Filter = "CSV文件|*.CSV";
            if (openFileDialog1.ShowDialog() == DialogResult.Cancel)
            {
                return;
            }
            else
            {
                this.dgvShow.DataSource = null;
                string fileName = openFileDialog1.FileName;
                this.dgvShow.DataSource = OpenCSV(fileName);
                MessageBox.Show("成功顯示CSV數據！");
            }
        }

 

        /// <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 DataTable OpenCSV(string fileName)
        {
            DataTable dt = new DataTable();
            FileStream fs = new FileStream(fileName, System.IO.FileMode.Open, System.IO.FileAccess.Read);
            StreamReader sr = new StreamReader(fs, System.Text.Encoding.Default);
            //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;
            //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)
            {
                aryLine=strLine.Split(',');
                if (IsFirst == true)
                {
                    IsFirst = false;
                    columnCount = aryLine.Length;
                    //建立列
                    for (int i = 0; i < columnCount; i++)
                    {
                        DataColumn dc = new DataColumn(aryLine[i]);
                        dt.Columns.Add(dc);
                    }
                }
                else
                {
                    DataRow dr = dt.NewRow();
                    for (int j = 0; j < columnCount; j++)
                    {
                        dr[j] = aryLine[j];
                    }
                    dt.Rows.Add(dr);
                }
            }

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