C#应用下的CSV文件写入和读出

1. 建立DataTable 类型

DataTable my_accurdt;
my_accurdt = new DataTable(DateTime.Now.ToString("yMMddHHmm") + "_AccurData");

2. 创建DataTable的列和行

//列
my_accurdt.Columns.Add(new DataColumn("Oder", typeof(int)));
my_accurdt.Columns.Add(new DataColumn("TimeStamp", typeof(string)));

//行
DataRow my_rows = my_accurdt.NewRow();
my_rows["Oder"] = dataTableOrder;
my_rows["TimeStamp"] = DateTime.Now.ToString("yMMddHHmm");
my_accurdt.Rows.Add(my_rows);

3. 把DataTable显示在WinForm的dataGridView控件中

Accur_table_dataGridView.DataSource = my_accurdt;

4. 创建写入CSV文件方法

        //write function
        public void writeDataCSV(string file_path, DataTable my_dt)
        {
            FileStream my_filestream;
            StreamWriter my_streamwriter;
            string my_data = null;
            if (!File.Exists(file_path))
            {
                my_filestream = new FileStream(file_path, FileMode.Create, FileAccess.Write);
                my_streamwriter = new StreamWriter(my_filestream, Encoding.UTF8);
                //write columns name
                for (int i = 0; i < my_dt.Columns.Count; i++)
                {
                    my_data += my_dt.Columns[i].ColumnName.ToString();
                    if (i < my_dt.Columns.Count - 1)
                    {
                        my_data += ",";
                    }
                }
                my_streamwriter.WriteLine(my_data);
            }
            else
            {
                my_filestream = new FileStream(file_path, FileMode.Append, FileAccess.Write);
                my_streamwriter = new StreamWriter(my_filestream, Encoding.UTF8);
            }
            //write rows
            for (int i = 0; i < my_dt.Rows.Count; i++)
            {
                my_data = null;
                for (int j = 0; j < my_dt.Columns.Count; j++)
                {
                    my_data += my_dt.Rows[i][j].ToString();
                    if (j < my_dt.Columns.Count - 1)
                    {
                        my_data += ",";
                    }
                }
                my_streamwriter.WriteLine(my_data);
            }
            my_streamwriter.Close();
            my_filestream.Close();
        }

5. 创建读出CSV文件方法

        //read function
        public DataTable readDataCSV(string file_path)
        {
            DataTable my_dt = new DataTable();
            FileStream my_filestream = new FileStream(file_path, FileMode.Open, FileAccess.Read);
            StreamReader my_streamreader = new StreamReader(my_filestream, Encoding.UTF8);
            string my_strLine = null;
            string[] my_arrayLine = null;
            bool isFirst = true;
            int my_dtColumns = 0;

            while ((my_strLine = my_streamreader.ReadLine()) != null)
            {
                my_strLine = my_strLine.Trim();
                my_arrayLine = my_strLine.Split(',');

                if (isFirst)
                {
                    my_dtColumns = my_arrayLine.Length;
                    for (int i = 0; i < my_dtColumns; i++)
                    {
                        my_dt.Columns.Add(my_arrayLine[i]);
                    }
                    isFirst = false;
                }
                else
                {
                    DataRow my_datarow = my_dt.NewRow();
                    for (int j = 0; j < my_dtColumns; j++)
                    {
                        if (my_arrayLine.Length > j)
                        {
                            my_datarow[j] = my_arrayLine[j];
                        }
                    }
                    my_dt.Rows.Add(my_datarow);
                }
            }
            my_streamreader.Close();
            my_filestream.Close();
            return my_dt;
        }

6. 创建文件保存路径选择框

        //file storage path
        public string SelectFolderPath()
        {
            string my_folderpath = string.Empty;
            FolderBrowserDialog my_folderbrowser = new FolderBrowserDialog();
            DialogResult my_result = my_folderbrowser.ShowDialog();
            if (my_result == DialogResult.OK)
            {
                my_folderpath = my_folderbrowser.SelectedPath;
                return my_folderpath;
            }
            else
            { return string.Empty; }
        }