vb用代码算出两个圆柱体的直径之差,可两个圆柱体都不是规则通径的圆柱体.只有圆心是一样的,

你是要算钢管的壁厚吧,你建两个二维数组a(0 to n,0 to 1),b(0 to n,0 to 1),a存外径数据,b存内径数据,a(i,0)是长度,a(i,1)是半径,长度为0时存一组数据,此后每次半径变动都存一组数据,管尾再存一次数据,这要靠你手工录入.
存好后,比如我要查长度100处的壁厚,代码如下：
dim i as double,r1 as double,r2 as double
for i =0 to ubound(a)-1
if a(i,0)100 then exit for
next for
if i=ubound(a) then
msgbox "未找到数据"
exit sub
else
r1=a(i,1)' 取得外径
end if
for i =0 to ubound(b)-1
if b(i,0)100 then exit for
next for
if i=ubound(b) then
msgbox "未找到数据"
exit sub
else
r2=b(i,1)' 取得内径
end if
msgbox "壁厚为：" & (r1=r2)