这个是COMBOBOX的通病! 在程序load的时候会调用COMBOBOX的SelectedIndexChanged事件,解决方法一:先指定COMBOBOX的DisplayMember和ValueMember,然后再SelectedIndexChanged事件里面做判断.解决方法二:在load中将ComboBox委托去掉, ComboBox1.SelectedIndexChanged -= new EventHandler(ComboBox1_SelectedIndexChanged);,在绑定ComboBox的DataSource后在注册。ComboBox1.SelectedIndexChanged += new EventHandler(ComboBox1_SelectedIndexChanged);解决方法三:自行google