1樓：匿名使用者
private sub command1_click()if not isnumeric(text1) thenmsgbox "***"
text1.setfocus
exit sub
end if
dim r as single
r = val(text1.text)
text2.text = 3.14 * r * rend sub
private sub command2_click()if not isnumeric(text2) thenmsgbox "***"
text2.setfocus
exit sub
end if
dim r as single
r = val(text1.text)
text3.text = 2 * 3.14 * rend sub
2樓：
不瞭解isnumeric,寫了個函式
private sub command1_click()dim r as single
if isval(trim(text1.text)) thenr = val(text1.text)
text2.text = 3.14 * r * relse
msgbox "input error"
text1.setfocus
end if
end sub
private sub command2_click()dim r as single
if isval(trim(text1.text)) thenr = val(text1.text)
text3.text = 2 * 3.14 * relse
msgbox "input error"
text1.setfocus
end if
end sub
function isval(str as string) as boolean
dim strcmp
dim i as integer
dim strtemp as stringstrcmp = "0123456789."
isval = true
for i = 1 to len(str)strtemp = mid(str, i, 1)if mid(str, i, 1) = "." and mid(str, i + 1, 1) = "" then
isval = false
exit function
end if
if instr(strcmp, strtemp) = 0 thenisval = false
exit function
end if
next
dim str1() as string
str1 = split(str)
if ubound(str1) > 0 thenisval = false
exit function
end if
end function
vb 輸入半徑，計算圓周長和圓面積
3樓：匿名使用者
執行通過，希望對你有幫助。
private sub command1_click()dim r as double
r = val(text1.text)
c = 2 * 3.14 * r
s = 3.14 * r * r
print "周長c="; c; "面積s="; send sub
private sub form_load()me.show
text1.text = ""
msgbox "請輸入要計算的圓的半徑"
text1.setfocus
end sub
vb程式設計 輸入圓半徑，計算圓周長和圓面積
4樓：匿名使用者
private sub command1_click()dim pi as single
dim r as single
dim l as single
dim a as single
pi = 3.141592654
r = inputbox("輸入半徑r=")l = pi * r
a = r ^ 2 * pi / 4
print "周長=", l
print "面積=", a
end sub
5樓：匿名使用者
private sub cmdok_click()dim pi as double
pi = 3.14
if isnumeric(trim(txtr.text)) = false then
msgbox "請輸入一個合法的數"
txtr.text = ""
txtr.setfocus
exit sub
end if
txtg.text = formatnumber((2 * pi * val(txtr.text)), 2)
txta.text = formatnumber(pi * val(txtr.text) * val(txtr.text), 2)
end sub
private sub form_load()txtr.text = ""
txtg.text = ""
txta.text = ""
me.show
txtr.setfocus
end sub
-----------------
txtr:半徑 txtg:周長 txta: 面積
輸入半徑，用vb編寫計算圓面積和圓周長的程式
6樓：殺神一刀斬
private sub label2_click()const pi = 3.14159
dim r as single, i as single, s as single
r = inputbox("請輸入半徑:", "輸入半徑")i = 2 * pi * r
s = pi * r ^ 2
label2 = label2 & r
label3 = label3 + str(i)label4 = label4 + str(s)end sub
當然你要有四個label控制元件，第一個可以隨便設定，例如寫成「計算圓的周長與面積」
7樓：匿名使用者
private sub command1_click()dim bj as single
dim zz as single
dim mj as single
bj = csng(text1.text)if bj <= 0 then
msgbox "你的輸入有誤"
exit sub
end if
mj = 3.1415 * bj * bjmsgbox "面積是" & format(mj, "0.00")end sub
private sub command2_click()dim bj as single
dim zz as single
dim mj as single
bj = csng(text1.text)if bj <= 0 then
msgbox "你的輸入有誤"
exit sub
end if
zz = 2 * bj * 3.1415
msgbox "周長是" & format(zz, "0.00")end sub
輸入半徑，計算出圓的周長和麵積，圓球的表面積和體積，並一起輸出。用C方式求解
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大圓周長是小圓一又四分之一倍，小圓面積比大圓面積少99平方釐米，求大圓面積
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周長相等的正方形和圓，邊長與半徑的比是面積之比是
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