private void tsbDownLoad_Click(object sender, EventArgs e) { // 下载数据 frmDownload download = frmDownload.CreateForm(); download.Show(); }
public static frmDownload CreateForm() { //判断是否存在该窗体,或时候该字窗体是否被释放过,如果不存在该窗体,则 new 一个字窗体 if (_instance == null || _instance.IsDisposed) { _instance = new frmDownload(); } return(_instance); }