You can utilize Tag
property of the Button
:
void Form1_DragDrop(object sender, DragEventArgs e)
{
foreach (String s e.Data.GetData(DataFormats.FileDrop))
{
Button button = new Button();
button.Click += new EventHandler(this.button_Click);
flowLayoutPanel1.Controls.Add(button);
path_app = String.Format("{0}", s);
// Add to Tag any data you want to pin to the button
button.Tag = path_app;
}
}
private void button_Click(object sender, System.EventArgs e)
{
// Obtain via Tag
String path_app = ((sender as Button).Tag as String);
myProcess.StartInfo.FileName = path_app;
myProcess.Start();
}