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How to: Customize Sorting in the Windows Forms DataGridView Control

The DataGridView control provides automatic sorting but, depending on your needs, you might need to customize sort operations. For example, you can use programmatic sorting to create an alternate user interface (UI). Alternatively, you can handle the SortCompare event or call the Sort(IComparer) overload of the Sort method for greater sorting flexibility, such as sorting multiple columns.

The following code examples demonstrate these three approaches to custom sorting. For more information, see Column Sort Modes in the Windows Forms DataGridView Control.

Programmatic Sorting

The following code example demonstrates a programmatic sort using the SortOrder and SortedColumn properties to determine the direction of the sort, and the SortGlyphDirection property to manually set the sort glyph. The Sort(DataGridViewColumn,ListSortDirection) overload of the Sort method is used to sort data only in a single column.

using System;
using System.ComponentModel;
using System.Windows.Forms;

class Form1 : Form
{
    private Button sortButton = new Button();
    private DataGridView dataGridView1 = new DataGridView();

    // Initializes the form.
    // You can replace this code with designer-generated code.
    public Form1()
    {
        dataGridView1.Dock = DockStyle.Fill;
        dataGridView1.AllowUserToAddRows = false;
        dataGridView1.SelectionMode =
            DataGridViewSelectionMode.ColumnHeaderSelect;
        dataGridView1.MultiSelect = false;

        sortButton.Dock = DockStyle.Bottom;
        sortButton.Text = "Sort";

        Controls.Add(dataGridView1);
        Controls.Add(sortButton);
        Text = "DataGridView programmatic sort demo";
    }

    // Establishes the main entry point for the application.
    [STAThreadAttribute()]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.Run(new Form1());
    }

    // Populates the DataGridView.
    // Replace this with your own code to populate the DataGridView.
    public void PopulateDataGridView()
    {
        // Add columns to the DataGridView.
        dataGridView1.ColumnCount = 2;
        dataGridView1.Columns[0].HeaderText = "Last Name";
        dataGridView1.Columns[1].HeaderText = "City";
        // Put the new columns into programmatic sort mode
        dataGridView1.Columns[0].SortMode =
            DataGridViewColumnSortMode.Programmatic;
        dataGridView1.Columns[1].SortMode =
            DataGridViewColumnSortMode.Programmatic;

        // Populate the DataGridView.
        dataGridView1.Rows.Add(new string[] { "Parker", "Seattle" });
        dataGridView1.Rows.Add(new string[] { "Watson", "Seattle" });
        dataGridView1.Rows.Add(new string[] { "Osborn", "New York" });
        dataGridView1.Rows.Add(new string[] { "Jameson", "New York" });
        dataGridView1.Rows.Add(new string[] { "Brock", "New Jersey" });
    }

    protected override void OnLoad(EventArgs e)
    {
        sortButton.Click += new EventHandler(sortButton_Click);

        PopulateDataGridView();
        base.OnLoad(e);
    }

    private void sortButton_Click(object sender, System.EventArgs e)
    {
        // Check which column is selected, otherwise set NewColumn to null.
        DataGridViewColumn newColumn =
            dataGridView1.Columns.GetColumnCount(
            DataGridViewElementStates.Selected) == 1 ?
            dataGridView1.SelectedColumns[0] : null;

        DataGridViewColumn oldColumn = dataGridView1.SortedColumn;
        ListSortDirection direction;

        // If oldColumn is null, then the DataGridView is not currently sorted.
        if (oldColumn != null)
        {
            // Sort the same column again, reversing the SortOrder.
            if (oldColumn == newColumn &&
                dataGridView1.SortOrder == SortOrder.Ascending)
            {
                direction = ListSortDirection.Descending;
            }
            else
            {
                // Sort a new column and remove the old SortGlyph.
                direction = ListSortDirection.Ascending;
                oldColumn.HeaderCell.SortGlyphDirection = SortOrder.None;
            }
        }
        else
        {
            direction = ListSortDirection.Ascending;
        }

        // If no column has been selected, display an error dialog  box.
        if (newColumn == null)
        {
            MessageBox.Show("Select a single column and try again.",
                "Error: Invalid Selection", MessageBoxButtons.OK,
                MessageBoxIcon.Error);
        }
        else
        {
            dataGridView1.Sort(newColumn, direction);
            newColumn.HeaderCell.SortGlyphDirection =
                direction == ListSortDirection.Ascending ?
                SortOrder.Ascending : SortOrder.Descending;
        }
    }
}

Custom Sorting Using the SortCompare Event

The following code example demonstrates custom sorting using a SortCompare event handler. The selected DataGridViewColumn is sorted and, if there are duplicate values in the column, the ID column is used to determine the final order.

#region Using directives

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Windows.Forms;

#endregion
class Form1 : Form
{
    private DataGridView dataGridView1 = new DataGridView();

    // Establish the main entry point for the application.
    [STAThreadAttribute()]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.Run(new Form1());
    }

    public Form1()
    {
        // Initialize the form.
        // This code can be replaced with designer generated code.
        dataGridView1.AllowUserToAddRows = false;
        dataGridView1.Dock = DockStyle.Fill;
        dataGridView1.SortCompare += new DataGridViewSortCompareEventHandler(
            this.dataGridView1_SortCompare);
        Controls.Add(this.dataGridView1);
        this.Text = "DataGridView.SortCompare demo";

        PopulateDataGridView();
    }

    // Replace this with your own population code.
    public void PopulateDataGridView()
    {
        // Add columns to the DataGridView.
        dataGridView1.ColumnCount = 3;

        // Set the properties of the DataGridView columns.
        dataGridView1.Columns[0].Name = "ID";
        dataGridView1.Columns[1].Name = "Name";
        dataGridView1.Columns[2].Name = "City";
        dataGridView1.Columns["ID"].HeaderText = "ID";
        dataGridView1.Columns["Name"].HeaderText = "Name";
        dataGridView1.Columns["City"].HeaderText = "City";

        // Add rows of data to the DataGridView.
        dataGridView1.Rows.Add(new string[] { "1", "Parker", "Seattle" });
        dataGridView1.Rows.Add(new string[] { "2", "Parker", "New York" });
        dataGridView1.Rows.Add(new string[] { "3", "Watson", "Seattle" });
        dataGridView1.Rows.Add(new string[] { "4", "Jameson", "New Jersey" });
        dataGridView1.Rows.Add(new string[] { "5", "Brock", "New York" });
        dataGridView1.Rows.Add(new string[] { "6", "Conner", "Portland" });

        // Autosize the columns.
        dataGridView1.AutoResizeColumns();
    }

    private void dataGridView1_SortCompare(object sender,
        DataGridViewSortCompareEventArgs e)
    {
        // Try to sort based on the cells in the current column.
        e.SortResult = System.String.Compare(
            e.CellValue1.ToString(), e.CellValue2.ToString());

        // If the cells are equal, sort based on the ID column.
        if (e.SortResult == 0 && e.Column.Name != "ID")
        {
            e.SortResult = System.String.Compare(
                dataGridView1.Rows[e.RowIndex1].Cells["ID"].Value.ToString(),
                dataGridView1.Rows[e.RowIndex2].Cells["ID"].Value.ToString());
        }
        e.Handled = true;
    }
}

Custom Sorting Using the IComparer Interface

The following code example demonstrates custom sorting using the Sort(IComparer) overload of the Sort method, which takes an implementation of the IComparer interface to perform a multiple-column sort.

#region Using directives

using System;
using System.Drawing;
using System.Windows.Forms;

#endregion

class Form1 : Form
{
    private DataGridView DataGridView1 = new DataGridView();
    private FlowLayoutPanel FlowLayoutPanel1 = new FlowLayoutPanel();
    private Button Button1 = new Button();
    private RadioButton RadioButton1 = new RadioButton();
    private RadioButton RadioButton2 = new RadioButton();

    // Establish the main entry point for the application.
    [STAThreadAttribute()]
    public static void Main()
    {
        Application.Run(new Form1());
    }

    public Form1()
    {
        // Initialize the form.
        // This code can be replaced with designer generated code.
        AutoSize = true;
        Text = "DataGridView IComparer sort demo";

        FlowLayoutPanel1.FlowDirection = FlowDirection.TopDown;
        FlowLayoutPanel1.Location = new System.Drawing.Point( 304, 0 );
        FlowLayoutPanel1.AutoSize = true;

        FlowLayoutPanel1.Controls.Add( RadioButton1 );
        FlowLayoutPanel1.Controls.Add( RadioButton2 );
        FlowLayoutPanel1.Controls.Add( Button1 );

        Button1.Text = "Sort";
        RadioButton1.Text = "Ascending";
        RadioButton2.Text = "Descending";
        RadioButton1.Checked = true;

        Controls.Add( FlowLayoutPanel1 );
        Controls.Add( DataGridView1 );
    }

    protected override void OnLoad( EventArgs e )
    {
        PopulateDataGridView();
        Button1.Click += new EventHandler(Button1_Click);

        base.OnLoad( e );
    }

    // Replace this with your own code to populate the DataGridView.
    private void PopulateDataGridView()
    {

        DataGridView1.Size = new Size(300, 300);

        // Add columns to the DataGridView.
        DataGridView1.ColumnCount = 2;

        // Set the properties of the DataGridView columns.
        DataGridView1.Columns[0].Name = "First";
        DataGridView1.Columns[1].Name = "Last";
        DataGridView1.Columns["First"].HeaderText = "First Name";
        DataGridView1.Columns["Last"].HeaderText = "Last Name";
        DataGridView1.Columns["First"].SortMode =
            DataGridViewColumnSortMode.Programmatic;
        DataGridView1.Columns["Last"].SortMode =
            DataGridViewColumnSortMode.Programmatic;

        // Add rows of data to the DataGridView.
        DataGridView1.Rows.Add(new string[] { "Peter", "Parker" });
        DataGridView1.Rows.Add(new string[] { "James", "Jameson" });
        DataGridView1.Rows.Add(new string[] { "May", "Parker" });
        DataGridView1.Rows.Add(new string[] { "Mary", "Watson" });
        DataGridView1.Rows.Add(new string[] { "Eddie", "Brock" });
    }

    private void Button1_Click( object sender, EventArgs e )
    {
        if ( RadioButton1.Checked == true )
        {
            DataGridView1.Sort( new RowComparer( SortOrder.Ascending ) );
        }
        else if ( RadioButton2.Checked == true )
        {
            DataGridView1.Sort( new RowComparer( SortOrder.Descending ) );
        }
    }

    private class RowComparer : System.Collections.IComparer
    {
        private static int sortOrderModifier = 1;

        public RowComparer(SortOrder sortOrder)
        {
            if (sortOrder == SortOrder.Descending)
            {
                sortOrderModifier = -1;
            }
            else if (sortOrder == SortOrder.Ascending)
            {
                sortOrderModifier = 1;
            }
        }

        public int Compare(object x, object y)
        {
            DataGridViewRow DataGridViewRow1 = (DataGridViewRow)x;
            DataGridViewRow DataGridViewRow2 = (DataGridViewRow)y;

            // Try to sort based on the Last Name column.
            int CompareResult = System.String.Compare(
                DataGridViewRow1.Cells[1].Value.ToString(),
                DataGridViewRow2.Cells[1].Value.ToString());

            // If the Last Names are equal, sort based on the First Name.
            if ( CompareResult == 0 )
            {
                CompareResult = System.String.Compare(
                    DataGridViewRow1.Cells[0].Value.ToString(),
                    DataGridViewRow2.Cells[0].Value.ToString());
            }
            return CompareResult * sortOrderModifier;
        }
    }
}

Compiling the Code

These examples require:

  • References to the System, System.Drawing, and System.Windows.Forms assemblies.

See also


Additional resources