对一个文本框添加拖拽功能：

private void txtFolder_DragEnter(object sender, DragEventArgs e)        {            if (e.Data.GetDataPresent(DataFormats.FileDrop))            {                e.Effect = DragDropEffects.Link;                this.txtFolder.Cursor = System.Windows.Forms.Cursors.Arrow;//指定鼠标形状               }            else            {                e.Effect = DragDropEffects.None;            }        }        private void txtFolder_DragDrop(object sender, DragEventArgs e)        {            //DataFormats 数据的格式，下有多个静态属性都为string型，除FileDrop格式外还有Bitmap,Text,WaveAudio等格式                string path = ((System.Array)e.Data.GetData(DataFormats.FileDrop)).GetValue(0).ToString();            this.txtFolder.Text = path;            this.txtFolder.Cursor = System.Windows.Forms.Cursors.IBeam; //还原鼠标形状         }