C#

DataTable dt = new DataTable();<br />
this.categoryTableAdapter.Fill(dt);<br />
dt.DefaultView.RowFilter = "category_id <> 1"; //some expresión for filtering<br />
categoryDataGridView.DataSource = dt

[DllImportAttribute("user32.dll")]<br />
public static extern bool ReleaseCapture();<br />
<br />
[DllImportAttribute("user32.dll")]<br />
public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);

private const int WM_NCLBUTTONDOWN = 0xA1;<br />
private const int HTCAPTION = 0x2;<br />
<br />
private void MoveForm()<br />
{<br />
    ReleaseCapture();<br />
    SendMessage(this.Handle, WM_NCLBUTTONDOWN, HTCAPTION, 0);<br />
}<br />
<br />
protected override void WndProc(ref Message m)<br />
{<br />
    base.WndProc(ref m);<br />
<br />
    int WM_NCHITTEST = 0x84;<br />
    if (m.Msg == WM_NCHITTEST)<br />
    {<br />
        int HTCLIENT = 1;<br />
        int HTCAPTION = 2;<br />
        if (m.Result.ToInt32() == HTCLIENT)<br />
        {<br />
            m.Result = (IntPtr)HTCAPTION;<br />
        }<br />
    }<br />
}

private void button1_MouseDown(object sender, MouseEventArgs e)<br />
{<br />
    if (e.Button == MouseButtons.Left)<br />
    {<br />
        this.MoveForm();<br />
    }<br />
}

[DllImportAttribute("user32.dll")]<br />
private extern static IntPtr GetForegroundWindow();

private void button1_Click(object sender, EventArgs e)
{
    MessageBox.Show(((Button)sender).Name);
}

if(sender is Button) { (Button)... }
if(sender is Label) { (Label)... }

Control c = Control.FromHandle(m.HWnd);
if(c != null)
{
    // we have the control that sent the message
    string name;    
    
    if(c is Button) { name = ((Button)c).Name; }
    else if(c is Label) { name = ((Label)c).Name; }
    ...
}

f (m.Msg == WM_LBUTTONCLICK)
{
???
???
???
}