C# DataGridView sorting with Generic List as underlying source

Question

Hi!

I'm using a Windows Forms DataGridView to display a generic list of MyObject objects.

First of all I wrap this collection into a BindingSource Collection, then:

dataGridView.DataSource = myBindingSource;

What I want to do is allow the user to sort the columns by clickin on the header of the column representing a concrete Property in MyObject.

I've read some articles that I should do sorting before binding. But it does not help me if I want to sort the columns in real time, being said when it's already binded.

The question is, what exactly do I need to do, so I could see the sorting arrows in DataGridView and I could sort every column ?

Answer 1

Hi, see this artice

http://msdn.microsoft.com/en-us/library/0868ft3z.aspx

by reading it i saw this "This method sorts the contents of the DataGridView by comparing values in the specified column. By default, the sort operation will use the Compare method to compare pairs of cells in the column using the DataGridViewCell..::.Value property."

Best Regards, iordan

Answer 2

My Solution is this:

I work with myBindingSource at my own, I do sorting, grouping ..whatever in a separate thread. Then I simply bind the result to the DataGridView.

myDataGridView.DataSource = bindingSource;

For this purpose I've setted all the columns to be sorted 'Programatically' (in designer) Then I manually add the arrow (ASCENDING / DESCENDING) by setting

cell.SortGlyphDirection = ... ;

in code behind.

Answer 3

Complete code to sort the column of datagridview whose datasource is a generic List

//----------------------------------------------------------------------------------------- //In the form - In constructor or form load, populate the grid. //--------------------------------------------------------------------------------------------

    List<student> students;

    private void PopulateList()
    {
        student std1 = new student("sss", 15, "Female");
        student std2 = new student("ddd", 12, "Male");
        student std3 = new student("zzz", 16, "Male");
        student std4 = new student("qqq", 14, "Female");
        student std5 = new student("aaa", 11, "Male");
        student std6 = new student("lll", 13, "Female");

        students = new List<student>();
        students.Add(std1);
        students.Add(std2);
        students.Add(std3);
        students.Add(std4);
        students.Add(std5);
        students.Add(std6);

        dataGridView1.DataSource = students;
    }

//---------------------------------------------------------------------------------------------

//Comparer class to perform sorting based on column name and sort order //---------------------------------------------------------------------------------------------

class StudentComparer : IComparer<Student>
{
    string memberName = string.Empty; // specifies the member name to be sorted
    SortOrder sortOrder = SortOrder.None; // Specifies the SortOrder.

    /// <summary>
    /// constructor to set the sort column and sort order.
    /// </summary>
    /// <param name="strMemberName"></param>
    /// <param name="sortingOrder"></param>
    public StudentComparer(string strMemberName, SortOrder sortingOrder)
    {
        memberName = strMemberName;
        sortOrder = sortingOrder;
    }

    /// <summary>
    /// Compares two Students based on member name and sort order
    /// and return the result.
    /// </summary>
    /// <param name="Student1"></param>
    /// <param name="Student2"></param>
    /// <returns></returns>
    public int Compare(Student Student1, Student Student2)
    {
        int returnValue = 1;
        switch (memberName)
        {
            case "Name" :
                if (sortOrder == SortOrder.Ascending)
                {
                    returnValue = Student1.Name.CompareTo(Student2.Name);
                }
                else
                {
                    returnValue = Student2.Name.CompareTo(Student1.Name);
                }

                break;
            case "Sex":
                if (sortOrder == SortOrder.Ascending)
                {
                    returnValue = Student1.Sex.CompareTo(Student2.Sex);
                }
                else
                {
                    returnValue = Student2.Sex.CompareTo(Student1.Sex);
                }
                break;
            default:
                if (sortOrder == SortOrder.Ascending)
                {
                    returnValue = Student1.Name.CompareTo(Student2.Name);
                }
                else
                {
                    returnValue = Student2.Name.CompareTo(Student1.StudentId);
                }
                break;
        }
        return returnValue;
    }
}

//---------------------------------------------------------------------------------------------

// Performing sort on click on Column Header //---------------------------------------------------------------------------------------------

    private void dataGridView1_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
    {
        //get the current column details
        string strColumnName = dataGridView1.Columns[e.ColumnIndex].Name;
        SortOrder strSortOrder = getSortOrder(e.ColumnIndex);

        students.Sort(new StudentComparer(strColumnName, strSortOrder));
        dataGridView1.DataSource = null;
        dataGridView1.DataSource = students;
        customizeDataGridView();
        dataGridView1.Columns[e.ColumnIndex].HeaderCell.SortGlyphDirection = strSortOrder;
    }

   /// <summary>
    /// Get the current sort order of the column and return it
    /// set the new SortOrder to the columns.
    /// </summary>
    /// <param name="columnIndex"></param>
    /// <returns>SortOrder of the current column</returns>
    private SortOrder getSortOrder(int columnIndex)
    {
        if (dataGridView1.Columns[columnIndex].HeaderCell.SortGlyphDirection == SortOrder.None ||
            dataGridView1.Columns[columnIndex].HeaderCell.SortGlyphDirection == SortOrder.Descending)
        {
            dataGridView1.Columns[columnIndex].HeaderCell.SortGlyphDirection = SortOrder.Ascending;
            return SortOrder.Ascending;
        }
        else
        {
            dataGridView1.Columns[columnIndex].HeaderCell.SortGlyphDirection = SortOrder.Descending;
            return SortOrder.Descending;
        }
    }