CheckBox 的State 状态有三种
cbUnchecked The check box has no check mark, indicating that the user has not selected the option.
cbChecked The check box has a check mark in it, indicating that the user has selected the option.
cbGrayed The check box has a check mark in it, but it is grayed.
通过CheckBox1->State 来判断 CheckBox的属性
CheckBox 的AllowGrayed 属性用来设置CheckBox的属相,默认的是false ,使得CheckBox只有两种状态,true的话可以设置为3中状态。属性Checked 可以判断Checkbox是否被单击