是一个表格控件，也是一个树状控件，整个表格的行列可以实现4层树状分支展开与收缩（类似与excel的表格行分组功能），同时树状控件里还带有checkbox按钮，可以表示表格的某行被选中与否-is a form controls, as well as a tree Controls throughout the ranks forms can be achieved four-storey tree branches start with