CODEWITHSUNDEEP
c#winformsdatagridview
Stuart Helwig
Stuart Helwig

Reputation: 9454

How do you highlight the row and/or column labels of a datagridview on mouseover of any cell (in c#)?

With a DataGridView control on a Windows form, when you move the mouse over a row label (or column label) it's (the label cell) background changes to a shade of blue (or other colour depending on your Windows colour scheme no doubt).

I would like to produce that effect when moving the mouse over any cell in the grid - i.e. highlight the row label for the row the mouse is currently hovering over.

The logic for changing the style of the current row is simple enough using mouseover event. I can change other attributes of the row (like say the backcolor) but I would really like something more subtle than that and I think highlighting of the row label would be very effective.

Can it be done - if so how? (C# preferably)

Upvotes: 2

Views: 9602

Answers (3)

Lucas
Lucas

Reputation: 639

I know you already have the response for this, but I will share something different.

This way, the whole row is painted. I just modified @BFree comments a little bit.

        private void dataGridView1_CellMouseEnter(object sender, DataGridViewCellEventArgs e)
    {
        if (e.RowIndex < 0 || e.ColumnIndex < 0) //column header / row headers
        {
            return;
        }
        foreach (DataGridViewCell cell in this.dataGridView1.Rows[e.RowIndex].Cells)
        {
           cell.Style.BackColor = Color.LightBlue;
        }
    }

    private void dataGridView1_CellMouseLeave(object sender, DataGridViewCellEventArgs e)
    {
        if (e.RowIndex < 0 || e.ColumnIndex < 0) //column header / row headers
        {
            return;
        }
        foreach (DataGridViewCell cell in this.dataGridView1.Rows[e.RowIndex].Cells)
        {
            cell.Style.BackColor = Color.White;
        }
    }

Upvotes: 2

SwDevMan81
SwDevMan81

Reputation: 49978

You could override the OnCellPainting event to do what you want. Depending on the size of your DataGridView, you might see flickering, but this should do what you want.


    class MyDataGridView : DataGridView
    {
        private int mMousedOverColumnIndex = int.MinValue;
        private int mMousedOverRowIndex = int.MinValue;

        protected override void OnCellMouseEnter(DataGridViewCellEventArgs e)
        {
            mMousedOverColumnIndex = e.ColumnIndex;
            mMousedOverRowIndex = e.RowIndex;
            base.OnCellMouseEnter(e);
            base.Refresh();
        }

        protected override void OnCellPainting(DataGridViewCellPaintingEventArgs e)
        {
            if (((e.ColumnIndex == mMousedOverColumnIndex) && (e.RowIndex == -1)) ||
                ((e.ColumnIndex == -1) && (e.RowIndex == mMousedOverRowIndex)))
            {
                PaintColumnHeader(e, System.Drawing.Color.Red);
            }
            base.OnCellPainting(e);
        }

        private void PaintColumnHeader(System.Windows.Forms.DataGridViewCellPaintingEventArgs e, System.Drawing.Color color)
        {
            LinearGradientBrush backBrush = new LinearGradientBrush(new System.Drawing.Point(0, 0), new System.Drawing.Point(100, 100), color, color);
            e.Graphics.FillRectangle(backBrush, e.CellBounds);
            DataGridViewPaintParts parts = (DataGridViewPaintParts.All & ~DataGridViewPaintParts.Background);
            e.AdvancedBorderStyle.Right = DataGridViewAdvancedCellBorderStyle.None;
            e.AdvancedBorderStyle.Left = DataGridViewAdvancedCellBorderStyle.None;
            e.Paint(e.ClipBounds, parts);
            e.Handled = true;
        }
    }

Upvotes: 9

BFree
BFree

Reputation: 103742

You can hook into the DataGridView's CellMouseEnter and CellMouseLeave events and then change the backcolor accordingly. Something like this:

    private void dataGridView1_CellMouseEnter(object sender, DataGridViewCellEventArgs e)
    {
        if (e.RowIndex < 0 || e.ColumnIndex < 0) //column header / row headers
        {
            return;
        } 

        this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Style.BackColor = Color.LightBlue;
    }

    private void dataGridView1_CellMouseLeave(object sender, DataGridViewCellEventArgs e)
    {
        if (e.RowIndex < 0 || e.ColumnIndex < 0) //column header / row headers
        {
            return;
        }

        this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Style.BackColor = Color.White;
    }

Upvotes: 2

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