private void Form1_DragEnter(object sender, System.Windows.Forms.DragEventArgs e)
 {
 if (e.Data.GetDataPresent(DataFormats.FileDrop))
 e.Effect = DragDropEffects.Link;
else e.Effect = DragDropEffects.None;
}

 private void

Form1_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)
 {
 //其中label1.Text显示的就是拖进文件的文件名；
 label1.Text = ((System.Array)e.Data.GetData(DataFormats.FileDrop)).GetValue(0).ToString();
}