Xin chào các bạn, bài viết hôm nay mình sẻ chia sẽ đến các bạn thư viện Tablehelper.cs để xuất dữ liệu từ một DataTable thành file text .txt có ô kẻ trong lập trình C#, Winform.

[C#] Export DataTable to Text File with border table

Thông thường khi các bạn ghi ra file Text, các bạn thường ngăn cách các dòng bởi một ký tự đặc biệt nào đó như: chấm phẩy, dấu | ...

Trong bài viết này mình đã viết sẵn class TableHelper.cs để lưu file text văn bản từ DataTable trong C#.

Giao diện demo ứng dụng Export Text File C#:

Đầu tiên các bạn tạo file TableHelper.cs:

using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ExportDataTableToTextFile
{
    public class TableHelper
    {
        private const string TopLeftJoint = "┌";
        private const string TopRightJoint = "┐";
        private const string BottomLeftJoint = "└";
        private const string BottomRightJoint = "┘";
        private const string TopJoint = "┬";
        private const string BottomJoint = "┴";
        private const string LeftJoint = "├";
        private const string MiddleJoint = "┼";
        private const string RightJoint = "┤";
        private const char HorizontalLine = '─';
        private const string VerticalLine = "│";

        private string[] _headers;
        private List<string[]> _rows = new List<string[]>();

        public int Padding { get; set; } = 1;
        public bool HeaderTextAlignRight { get; set; }
        public bool RowTextAlignRight { get; set; }

        public void WriteDataTableToTextFile(DataTable dataTable, string PathFileName, bool hasHeader = true)
        {
            var table = new TableHelper();
            if (hasHeader)
            {
                string[] columnNames = dataTable.Columns.Cast<DataColumn>()
                                .Select(x => x.ColumnName)
                                .ToArray();

                table.SetHeaders(columnNames);
            }
            foreach (DataRow row in dataTable.Rows)
            {
                var rowArray = row.ItemArray.Cast<string>().ToArray();
                table.AddRow(rowArray);
            }

            File.WriteAllText(PathFileName, table.ToString());           
                
        }
        public void SetHeaders(params string[] headers)
        {
            _headers = headers;
        }

        public void AddRow(params string[] row)
        {
            _rows.Add(row);
        }

        public void ClearRows()
        {
            _rows.Clear();
        }

        private int[] GetMaxCellWidths(List<string[]> table)
        {
            var maximumColumns = 0;
            foreach (var row in table)
            {
                if (row.Length > maximumColumns)
                    maximumColumns = row.Length;
            }

            var maximumCellWidths = new int[maximumColumns];
            for (int i = 0; i < maximumCellWidths.Count(); i++)
                maximumCellWidths[i] = 0;

            var paddingCount = 0;
            if (Padding > 0)
            {
                //Padding is left and right
                paddingCount = Padding * 2;
            }

            foreach (var row in table)
            {
                for (int i = 0; i < row.Length; i++)
                {
                    var maxWidth = row[i].Length + paddingCount;

                    if (maxWidth > maximumCellWidths[i])
                        maximumCellWidths[i] = maxWidth;
                }
            }

            return maximumCellWidths;
        }

        private StringBuilder CreateTopLine(int[] maximumCellWidths, int rowColumnCount, StringBuilder formattedTable)
        {
            for (int i = 0; i < rowColumnCount; i++)
            {
                if (i == 0 && i == rowColumnCount - 1)
                    formattedTable.AppendLine(string.Format("{0}{1}{2}", TopLeftJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine), TopRightJoint));
                else if (i == 0)
                    formattedTable.Append(string.Format("{0}{1}", TopLeftJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine)));
                else if (i == rowColumnCount - 1)
                    formattedTable.AppendLine(string.Format("{0}{1}{2}", TopJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine), TopRightJoint));
                else
                    formattedTable.Append(string.Format("{0}{1}", TopJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine)));
            }

            return formattedTable;
        }

        private StringBuilder CreateBottomLine(int[] maximumCellWidths, int rowColumnCount, StringBuilder formattedTable)
        {
            for (int i = 0; i < rowColumnCount; i++)
            {
                if (i == 0 && i == rowColumnCount - 1)
                    formattedTable.AppendLine(string.Format("{0}{1}{2}", BottomLeftJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine), BottomRightJoint));
                else if (i == 0)
                    formattedTable.Append(string.Format("{0}{1}", BottomLeftJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine)));
                else if (i == rowColumnCount - 1)
                    formattedTable.AppendLine(string.Format("{0}{1}{2}", BottomJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine), BottomRightJoint));
                else
                    formattedTable.Append(string.Format("{0}{1}", BottomJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine)));
            }

            return formattedTable;
        }

        private StringBuilder CreateValueLine(int[] maximumCellWidths, string[] row, bool alignRight, StringBuilder formattedTable)
        {
            int cellIndex = 0;
            int lastCellIndex = row.Length - 1;

            var paddingString = string.Empty;
            if (Padding > 0)
                paddingString = string.Concat(Enumerable.Repeat(' ', Padding));

            foreach (var column in row)
            {
                var restWidth = maximumCellWidths[cellIndex];
                if (Padding > 0)
                    restWidth -= Padding * 2;

                var cellValue = alignRight ? column.PadLeft(restWidth, ' ') : column.PadRight(restWidth, ' ');

                if (cellIndex == 0 && cellIndex == lastCellIndex)
                    formattedTable.AppendLine(string.Format("{0}{1}{2}{3}{4}", VerticalLine, paddingString, cellValue, paddingString, VerticalLine));
                else if (cellIndex == 0)
                    formattedTable.Append(string.Format("{0}{1}{2}{3}", VerticalLine, paddingString, cellValue, paddingString));
                else if (cellIndex == lastCellIndex)
                    formattedTable.AppendLine(string.Format("{0}{1}{2}{3}{4}", VerticalLine, paddingString, cellValue, paddingString, VerticalLine));
                else
                    formattedTable.Append(string.Format("{0}{1}{2}{3}", VerticalLine, paddingString, cellValue, paddingString));

                cellIndex++;
            }

            return formattedTable;
        }

        private StringBuilder CreateSeperatorLine(int[] maximumCellWidths, int previousRowColumnCount, int rowColumnCount, StringBuilder formattedTable)
        {
            var maximumCells = Math.Max(previousRowColumnCount, rowColumnCount);

            for (int i = 0; i < maximumCells; i++)
            {
                if (i == 0 && i == maximumCells - 1)
                {
                    formattedTable.AppendLine(string.Format("{0}{1}{2}", LeftJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine), RightJoint));
                }
                else if (i == 0)
                {
                    formattedTable.Append(string.Format("{0}{1}", LeftJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine)));
                }
                else if (i == maximumCells - 1)
                {
                    if (i > previousRowColumnCount)
                        formattedTable.AppendLine(string.Format("{0}{1}{2}", TopJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine), TopRightJoint));
                    else if (i > rowColumnCount)
                        formattedTable.AppendLine(string.Format("{0}{1}{2}", BottomJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine), BottomRightJoint));
                    else if (i > previousRowColumnCount - 1)
                        formattedTable.AppendLine(string.Format("{0}{1}{2}", MiddleJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine), TopRightJoint));
                    else if (i > rowColumnCount - 1)
                        formattedTable.AppendLine(string.Format("{0}{1}{2}", MiddleJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine), BottomRightJoint));
                    else
                        formattedTable.AppendLine(string.Format("{0}{1}{2}", MiddleJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine), RightJoint));
                }
                else
                {
                    if (i > previousRowColumnCount)
                        formattedTable.Append(string.Format("{0}{1}", TopJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine)));
                    else if (i > rowColumnCount)
                        formattedTable.Append(string.Format("{0}{1}", BottomJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine)));
                    else
                        formattedTable.Append(string.Format("{0}{1}", MiddleJoint, string.Empty.PadLeft(maximumCellWidths[i], HorizontalLine)));
                }
            }

            return formattedTable;
        }

        public override string ToString()
        {
            var table = new List<string[]>();

            var firstRowIsHeader = false;
            if (_headers?.Any() == true)
            {
                table.Add(_headers);
                firstRowIsHeader = true;
            }

            if (_rows?.Any() == true)
                table.AddRange(_rows);

            if (!table.Any())
                return string.Empty;

            var formattedTable = new StringBuilder();

            var previousRow = table.FirstOrDefault();
            var nextRow = table.FirstOrDefault();

            int[] maximumCellWidths = GetMaxCellWidths(table);

            formattedTable = CreateTopLine(maximumCellWidths, nextRow.Count(), formattedTable);

            int rowIndex = 0;
            int lastRowIndex = table.Count - 1;

            for (int i = 0; i < table.Count; i++)
            {
                var row = table[i];

                var align = RowTextAlignRight;
                if (i == 0 && firstRowIsHeader)
                    align = HeaderTextAlignRight;

                formattedTable = CreateValueLine(maximumCellWidths, row, align, formattedTable);

                previousRow = row;

                if (rowIndex != lastRowIndex)
                {
                    nextRow = table[rowIndex + 1];
                    formattedTable = CreateSeperatorLine(maximumCellWidths, previousRow.Count(), nextRow.Count(), formattedTable);
                }

                rowIndex++;
            }

            formattedTable = CreateBottomLine(maximumCellWidths, previousRow.Count(), formattedTable);

            return formattedTable.ToString();
        }
    }
}

Và Source code sử dụng cho Form1.cs xuất Table ra Text file

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace ExportDataTableToTextFile
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        DataTable table;
        private void btnWriteFile_Click(object sender, EventArgs e)
        {
            new TableHelper().WriteDataTableToTextFile(table, "info.txt");
            Process.Start(Application.StartupPath + "\\" + "info.txt");
          
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            table = new DataTable();
            table.Columns.Add("ID");
            table.Columns.Add("Name");
            table.Columns.Add("Gender");
            table.Columns.Add("Day of Birth");
            table.Columns.Add("Address");

            table.Rows.Add(1, "Nguyễn Thảo", "Nam", "28/03/1988", "Bà Rịa Vũng Tàu");
            table.Rows.Add(2, "Nguyễn Phương Nhi", "Nữ", "28/10/2020", "Bà Rịa Vũng Tàu");
            table.Rows.Add(3, "Nguyễn Đình Tuyên", "Nam", "19/12/2014", "Quảng Bình");
            table.Rows.Add(4, "Trịnh Quốc Khang", "Nam", "01/01/1998", "Đồng Nai");
            table.Rows.Add(5, "Võ Sơn Băng", "Nam", "10/03/1988", "Vĩnh Long");
            table.Rows.Add(6, "Cái Trí Minh", "Nam", "10/05/1997", "Đồng Nai");
            table.Rows.Add(7, "Hoàng Dược Sư", "Nam", "17/08/1987", "Đông Tà");
            table.Rows.Add(8, "Âu Dương Phong", "Nam", "19/10/2005", "Tây Độc");
            table.Rows.Add(9, "Hồng Thất Công", "Nam", "18/03/1987", "Bắc Cái");
            table.Rows.Add(10, "Dương Quá", "Nam", "18/03/1988", "Trung Quốc");
            table.Rows.Add(11, "Long Nhi", "Nữ", "05/03/1988", "China");
            table.Rows.Add(12, "Hoàng Dung", "Nữ", "05/03/1988", "Hồng Kông");
            table.Rows.Add(13, "Doãn Chí Bình", "Nam", "15/03/1988", "Ma Cau");
            table.Rows.Add(14, "Trương Vô Kỵ", "Nam", "15/03/1988", "Ma Cau");
            table.Rows.Add(15, "Trương Tam Phong", "Nam", "15/03/1988", "Ma Cau");
            
            dataGridView1.DataSource = table;
        }
    }
}

Thanks for watching!

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