var x,y:array [0..50] of integer;
canvas.pen.color:=clred;
canvas.pen.style:=psDash;
form1.canvas.moveto(trunc(x[i]),trunc(y[i]));
form1.canvas.lineto(trunc(x[j]),trunc(y[j]));
canvas.pen.color:=clred;
canvas.pen.style:=psDash;
form1.canvas.moveto(trunc(x[i]),trunc(y[i]));
form1.canvas.lineto(trunc(x[j]),trunc(y[j]));
做一个链表记录下每一条线的坐标,然后再mousedown事件里判断鼠标的点是否在某条线的区域内
其它形状的的图形类似处理