CODEWITHSUNDEEP
c#sortingdatagridview
bsh152s
bsh152s

Reputation: 3218

How do I implement automatic sorting of DataGridView?

I am programmatically adding columns to a DataGridView and then binding to a list. By default, the SortMode of the columns are Automatic. But when I run my app, clicking on the headers does nothing. The up/down arrows aren't showing up. From reading MSDN, not much is said about automatic sorting. They go into more detail about programmatic sorting. So, I'm assuming the automatic way should be easy. MSDN goes on to say "Unless column headers are used for selection, clicking the column header automatically sorts the DataGridView by this column and displays a glyph indicating the sort order." What exactly does that mean? Could I be setting a grid property that conflicts with the sorting? What am I missing?

AutoGenerateColumns = false;
AllowUserToAddRows = false;
AllowUserToDeleteRows = false;
AllowUserToResizeRows = false;
AllowUserToResizeColumns = false;
ColumnHeadersHeightSizeMode = DataGridViewColumnHeadersHeightSizeMode.DisableResizing;
ReadOnly = true;
MultiSelect = false;
RowHeadersVisible = false;
SelectionMode = DataGridViewSelectionMode.FullRowSelect;
CellBorderStyle = DataGridViewCellBorderStyle.None;


    DataGridViewTextBoxColumn idColumn = new DataGridViewTextBoxColumn();
    idColumn.HeaderText = "ID";
    idColumn.DataPropertyName = "IDNumber";

    DataGridViewTextBoxColumn nameColumn = new DataGridViewTextBoxColumn();
    nameColumn.HeaderText = "Name";
    nameColumn.DataPropertyName = "Description";

    DataGridViewTextBoxColumn lastModifiedColumn = new DataGridViewTextBoxColumn();
    lastModifiedColumn.HeaderText = "Last Modified";
    lastModifiedColumn.DataPropertyName = "Date";

    Columns.Add(idColumn);
    Columns.Add(nameColumn);
    Columns.Add(lastModifiedColumn);

    List<IMyObject> bindingList = GetMyList();
    DataSource = bindingList;

Upvotes: 15

Views: 36030

Answers (4)

Thierry Br&#233;mard
Thierry Br&#233;mard

Reputation: 899

I have just no words .... there exist solution which override default BindingList<>.... because BindingList hides a protected property which is a flag which indicate if the sorting is supported:

enter image description here

msdn:

The SupportsSortingCore property indicates whether the BindingList supports sorting with the ApplySortCore method.

The BindingList class does not provide a base implementation of sorting, so SupportsSortingCore always returns false by default. For more information about implementing sorting, see the ApplySortCore method.

you can strech and brute force properties of you datagrid view, if you are bound to a BindingList<> you will NEVER manage to sort it !

Upvotes: 0

mbomb007
mbomb007

Reputation: 4231

Best solution I've found:

EDIT: Since posting I found this implementation of SortableBindingList(Of T) to be the best solution, with the exception that I modified line 52 to be IEnumerable rather than ICollection, since the constructor is casting anyway and it works.

Alternatively, the solution below needs no custom class:

The DataGridView may be sorted without implementing a custom class. Note that my code is in VB.NET, but it should translate. The data must first be added to the grid.Rows:

For Each item In dataList
    grid.Rows.Add(item.Id, item.Name, item.DateProperty)
Next

Then implement these event handlers. The second one is to ensure that date sorting works. You only need it if your grid will have a sortable date column:

Private Sub grid_ColumnHeaderMouseClick(ByVal sender As Object, ByVal e As DataGridViewCellMouseEventArgs) Handles grid.ColumnHeaderMouseClick
    Dim col = grid.Columns(e.ColumnIndex)
    Dim dir As System.ComponentModel.ListSortDirection

    Select Case col.HeaderCell.SortGlyphDirection
        Case SortOrder.None, SortOrder.Ascending
            dir = System.ComponentModel.ListSortDirection.Ascending
        Case Else
            dir = System.ComponentModel.ListSortDirection.Descending
    End Select

    grid.Sort(col, dir)
End Sub

Private Sub grid_SortCompare(ByVal sender As Object, ByVal e As DataGridViewSortCompareEventArgs) Handles grid.SortCompare
    'This event occurs only when the DataSource property is not set and the VirtualMode property value is false.

    If e.Column.Name = "DateProperty" Then
        e.SortResult = Date.Compare(CType(e.CellValue1, Date), CType(e.CellValue2, Date))

        e.Handled = True
    End If

End Sub

An important thing to note is that only the properties you add to the row are part of the resulting object, since there is no binding. In order to maintain your entire object, you will need to add columns for every property, setting the columns Visible = False for any that should not be displayed.

Upvotes: 2

Chris Doggett
Chris Doggett

Reputation: 20757

We use BindingListView to bind List<T>s to DataGridViews, and it's worked beautifully for us.

Here is a very simple example of creating a view of a list of objects (in C#):

List<Customer> customers = GetCustomers();
BindingListView<Customer> view = new BindingListView<Customer>(customers);
dataGridView1.DataSource = view;

Check out https://stackoverflow.com/a/17952576/116891 for a lot more details about DGV sorting and databinding.

If you don't want to add something that heavy, you can try this implementation of a SortableBindingList<T> (with updates).

Both give you sorting right out of the box, and BindingListView is even faster than DataViews, according to their benchmarks.

Upvotes: 23

Michael J
Michael J

Reputation: 2545

I think I found the answer. My datasource implements IList<T>. Apparently it need to implement IBindingList<T>. Unfortunately, I'm not able to test this.

Upvotes: 1

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