/// <summary>
/// 单例模式，返回单个窗体对象
/// </summary>
/// <returns></returns>
public static FrmBarcode GetSingleton()
{
//if(frm==null || frm.IsDisposed)
if (frm == null)
{
frm = new FrmBarcode();
}
return(frm);
}
private void FrmBarcode_FormClosing(object sender, FormClosingEventArgs e)
{
videoSourcePlayer1.SignalToStop();
videoSourcePlayer1.WaitForStop();
videoSourcePlayer2.SignalToStop();
videoSourcePlayer2.WaitForStop();
frm = null;
serialPort1.Close();
}