delphi编程实现控件自由拖动，费了1天心血，实现控件的任意拖动和调整大小，继承自TConrol类的，任何控件都可以自由实现，稍作修改即可使用，对初学者有较大意义。- Delphi programming controls free drag, spent 1 days of effort, to achieve drag and resize controls, inherited the TConrol class, any control can achieve free, minor