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);
}