//创建窗体对象的静态方法
public static AddParticipant InstanceObject()
{
if (_instance == null)
{
_instance = new AddParticipant();
}
return(_instance);
}
//窗体关闭事件
private void AddParticipant_FormClosing(object sender, FormClosingEventArgs e)
{
_instance = null;
}