使用ColorDialog更改dataGridViewCells的背景颜色

Question

So I have a dataGridView and I want to be able to select a cell and change its color. This is a homework assignment in which we are required to use a ColorDialog. I have a button at the top that brings up a ColorDialog to choose from, and I have been able to successfully change a cell's background color using this, but only a specific cell (just tested out (2,2)). I want it to only change the color of the cell selected. How do I let the ColorDialog know which cell is currently selected? My current code for clicking the actual button is this:

private void changeBGColorToolStripMenuItem_Click(object sender, EventArgs e)
{
    ColorDialog cd = new ColorDialog();
    cd.ShowDialog();
    dataGridView1.Rows[2].Cells[2].Style.BackColor = cd.Color;
}

Like I said before I tested out (2,2) just to get it to work, and it does change that specific cell. I just want to know how to let this function know WHICH cell I actually have selected (or whether I have a cell selected at all!). I also have a CellBeginEdit and CellEndEdit functions if that helps. Thank you!

Answer 1

Close. First I suggest you use this syntax to check for OK:

        if (ColorDialog .ShowDialog() == DialogResult.OK)
           dataGridView1.Rows[2].Cells[2].Style.BackColor = ColorDialog .Color;

or, shorter:

        if (ColorDialog .ShowDialog() == DialogResult.OK)
           dataGridView1[2][2].Style.BackColor = ColorDialog .Color;

To reference the selected cell use this:

dataGridView1.SelectedCells[0]

This actually says 'the first selected cell'. So you should make sure that either multiselect if off of or that you change colors for all selected cells.

So it will be either

        if (ColorDialog .ShowDialog() == DialogResult.OK)
           dataGridView1.SelectedCells[0].Style.BackColor = ColorDialog 

or

       if (ColorDialog .ShowDialog() == DialogResult.OK)
       {
           foreach (DataGridViewCell cell in DataGridView1.SelectedCells)
              cell.Style.BackColor = ColorDialog
       }

Also in the first case you must check that there actually is a first selected cell, ie that there are selected cells in the first place, or the reference will throw an error. Check for dataGridView1.SelectedCells.Length > 0 . You decide where to put the check..