C# – How to get a specific cell in a DataGridView on selection changed

cdatagridviewselectionchangedwinforms

With a listbox, I have the following code to extract the item selected:

    private void inventoryList_SelectedIndexChanged(object sender, EventArgs e)
    {
        String s = inventoryList.SelectedItem.ToString();
        s = s.Substring(0, s.IndexOf(':'));
        bookDetailTable.Rows.Clear();
        ...
        more code
        ...
    }

I want to do something similar for a DataGridView, that is, when the selection changes, retrieve the contents of the first cell in the row selected. The problem is, I don't know how to access that data element.

Any help is greatly appreciated.

Best Answer

I think that this is what you're looking for. But if not, hopefully it will give you a start.

private void dataGridView1_SelectionChanged(object sender, EventArgs e)
{
    DataGridView dgv = (DataGridView)sender;

    //User selected WHOLE ROW (by clicking in the margin)
    if (dgv.SelectedRows.Count> 0)
       MessageBox.Show(dgv.SelectedRows[0].Cells[0].Value.ToString());

    //User selected a cell (show the first cell in the row)
    if (dgv.SelectedCells.Count > 0)
        MessageBox.Show(dgv.Rows[dgv.SelectedCells[0].RowIndex].Cells[0].Value.ToString());

    //User selected a cell, show that cell
    if (dgv.SelectedCells.Count > 0)
        MessageBox.Show(dgv.SelectedCells[0].Value.ToString());
}

Related Solutions

C# – How to get a consistent byte representation of strings in C# without manually specifying an encoding

Contrary to the answers here, you DON'T need to worry about encoding if the bytes don't need to be interpreted!

Like you mentioned, your goal is, simply, to "get what bytes the string has been stored in".
(And, of course, to be able to re-construct the string from the bytes.)

For those goals, I honestly do not understand why people keep telling you that you need the encodings. You certainly do NOT need to worry about encodings for this.

Just do this instead:

static byte[] GetBytes(string str)
{
    byte[] bytes = new byte[str.Length * sizeof(char)];
    System.Buffer.BlockCopy(str.ToCharArray(), 0, bytes, 0, bytes.Length);
    return bytes;
}

// Do NOT use on arbitrary bytes; only use on GetBytes's output on the SAME system
static string GetString(byte[] bytes)
{
    char[] chars = new char[bytes.Length / sizeof(char)];
    System.Buffer.BlockCopy(bytes, 0, chars, 0, bytes.Length);
    return new string(chars);
}

As long as your program (or other programs) don't try to interpret the bytes somehow, which you obviously didn't mention you intend to do, then there is nothing wrong with this approach! Worrying about encodings just makes your life more complicated for no real reason.

Additional benefit to this approach: It doesn't matter if the string contains invalid characters, because you can still get the data and reconstruct the original string anyway!

It will be encoded and decoded just the same, because you are just looking at the bytes.

If you used a specific encoding, though, it would've given you trouble with encoding/decoding invalid characters.

C# – DataGridView get current selected object

DataGridViewRow.DataBoundItem contains the 'business' object it is bound to.

Best Answer

Related Solutions

C# – How to get a consistent byte representation of strings in C# without manually specifying an encoding

C# – DataGridView get current selected object

Related Topic