internal void Form1_DragEnter(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(DataFormats.FileDrop) || e.Data.GetDataPresent(DataFormats.Text) || e.Data.GetFormats().ToString().Equals("System.String[]"))
{
e.Effect = DragDropEffects.All;
}
else
{
e.Effect = DragDropEffects.None;
}
}