title: How add filter to datagridview
body: <p>I am trying to load a csv file to datagridview
  and now i want to add filtering to the datagridview</p>
  
  <p>How to do?
  Here's how I read and load csv file</p>
  
  <pre><code>openFileDialog1.InitialDirectory = @"C:\";
  openFileDialog1.Title = "Open CSV Files";
  openFileDialog1.CheckFileExists = true;
  openFileDialog1.CheckPathExists = true;
  openFileDialog1.DefaultExt = "CSV";
  openFileDialog1.Filter = "CSV files (*.csv)|*.csv|All files(*.*)|*.*";
  openFileDialog1.FilterIndex = 1;
  openFileDialog1.RestoreDirectory = true;
  try
  {
      if (openFileDialog1.ShowDialog() == DialogResult.OK)
      {
          string csvPath = openFileDialog1.FileName;
          string rowValue;
          // int rowValue = int.Parse(??);
          string[] cellValue;
          dataGridView1.Rows.Clear();
          //dataGridView1.Columns.Clear();
          if (System.IO.File.Exists(csvPath))
          {
              System.IO.StreamReader fileReader = new StreamReader(csvPath);
              rowValue = fileReader.ReadLine();
              cellValue = rowValue.Split(',');
  
  
  
              for (int i = 0; i &lt;= cellValue.Count() - 1; i++)
              {
                  DataGridViewTextBoxColumn column = new DataGridViewTextBoxColumn();
                  column.Name = cellValue[i];    //column name , value
                  column.HeaderText = cellValue[i];
                  dataGridView1.Columns.Add(column);
                  // dataGridView1.Columns[].CellType = typeof(Int64);
                  //Conver.ToString
                  dataGridView1.ColumnHeadersDefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter; // Korean? 칼럼 헤더 가운데 정렬
               //   dataGridView1.RowHeadersDefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter;
                 // dataGridView1.Columns[0].DataPropertyName = "field name";
              }
              while (fileReader.Peek() != -1)
              {
                  rowValue = fileReader.ReadLine();
                  cellValue = rowValue.Split(',');
                  dataGridView1.Rows.Add(cellValue);
              }
              fileReader.Dispose();
              fileReader.Close();`
  </code></pre>