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在解决iif问题时，为了判断iif语句是否合法，同时找出其中的条件，返回值true及返回值false。却不自然中写出了一个通用的函数模块，该函数能解决闭合符号形式中的一串文字。如”( … )”、”[ … ]”等，看官也可以自己设定一个闭合符号或字符串，但必须是对称出现，如“avb”和“def”便可以组合成一对，这样对于字符串avbcdeokdef的闭合符号中。现将这些函数整理如下，参数、返回值及函数功用都已经在注释中说明，希望本函数模块能对vb忠实爱好者有所帮助。
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从某一段文字中查找某一个符号(须考虑大小写)，并且返回该符号的所有位置索引
douhapy 2005-01-31
参数:
strsentence :任意一段文字
strsymbol :需要查找的特殊符号，或字符串
symbolindex() :返回该符号在文字中的所处位置索引
blcasematch :是否必须大小写匹配 (true 大小写必须匹配)
bldesc :是否降序排列symbolindex中的数据(true 为降序排列索引)
返回值:
true 成功找到该符号，同时symbolindex有相应的值
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function checksymbolfromsentence(byval strsentence as string, byval strsymbol as string, _
byref symbolindex() as integer, optional byval blcasematch = true, optional byval bldesc = false) as boolean
dim intsymbolindex() as integer
dim strtmp as string
dim inttmp as integer
dim blreturn as boolean
dim i as integer
strtmp = strsentence: blreturn = false: i = 0
if bldesc then
if blcasematch then
inttmp = instrrev(strtmp, strsymbol)
else
inttmp = instrrev(strtmp, strsymbol, -1, vbtextcompare)
end if
else
if blcasematch then
inttmp = instr(strtmp, strsymbol)
else
inttmp = instr(1, strtmp, strsymbol, vbtextcompare)
end if
end if
do while inttmp <> 0
blreturn = true
redim preserve intsymbolindex(i)
intsymbolindex(i) = inttmp
inttmp = inttmp – 1
if inttmp <> 0 then
if bldesc then
if blcasematch then
inttmp = instrrev(strtmp, strsymbol, inttmp)
else
inttmp = instrrev(strtmp, strsymbol, inttmp, vbtextcompare)
end if
else
if blcasematch then
inttmp = instr(inttmp + 1, strtmp, strsymbol)
else
inttmp = instr(inttmp + 1, strtmp, strsymbol, vbtextcompare)
end if
end if
end if
i = i + 1
loop
checksymbolfromsentence = blreturn
symbolindex = intsymbolindex
erase intsymbolindex
end function
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获取任意一段文字"( … )"闭合符号中的字符串数据
douhapy 2005-01-31
参数:
strsentence :任意一段文字
leftbracketindex:该段文字中闭合符号左符号的索引
leftclosesymbol :闭合符号的左符号
rightclosesymbol:闭合符号的右符号
blcasematch :是否必须大小写匹配 (true 大小写必须匹配)
返回值
若成功 则返回闭合括号中的字符串
否则 返回空字符串
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function getclosestring(byval strsentence as string, byval leftbracketindex as integer, _
optional byval leftclosesymbol as string = "(", optional byval rightclosesymbol as string = ")", _
optional byval blcasematch as boolean = true) as string
dim strreturn as string
dim strtmp as string
dim intleftbracketindex() as integer 所有左括号的位置
dim intrightbracketindex() as integer 所有右括号的位置
dim i as integer
dim j as integer
dim m as integer
dim mintleftbracketindex as integer
dim mintrightbracketindex as integer
strtmp = strsentence: strreturn = ""
查找第一个左括号
if blcasematch then
mintleftbracketindex = instr(1, strsentence, leftclosesymbol)
else
mintleftbracketindex = instr(1, strsentence, leftclosesymbol, vbtextcompare)
end if
if mintleftbracketindex <> 0 then
if ucase(mid(strsentence, leftbracketindex, len(leftclosesymbol))) = ucase(leftclosesymbol) then
mintleftbracketindex = leftbracketindex
end if
else
goto endlab
end if
获取所有的左括号和右括号的位置
call checksymbolfromsentence(strtmp, leftclosesymbol, intleftbracketindex, blcasematch, true)
call checksymbolfromsentence(strtmp, rightclosesymbol, intrightbracketindex, blcasematch, true)
if ubound(intleftbracketindex) = ubound(intrightbracketindex) then
循环查找匹配的左右对称括号,同时将数据置为0
for i = 0 to ubound(intleftbracketindex)
for j = 0 to ubound(intrightbracketindex)
if intrightbracketindex(j) <> 0 then
if intrightbracketindex(j) < intleftbracketindex(i) then
exit for
end if
if j = ubound(intrightbracketindex) then
j = j + 1: exit for
end if
end if
next
for m = j – 1 to 0 step -1
if intrightbracketindex(m) <> 0 then
if intleftbracketindex(i) = mintleftbracketindex then
mintrightbracketindex = intrightbracketindex(m)
end if
intrightbracketindex(m) = 0
exit for
end if
next
next
strreturn = mid(strtmp, mintleftbracketindex + len(leftclosesymbol), _
mintrightbracketindex – mintleftbracketindex – len(rightclosesymbol))
end if
endlab:
getclosestring = strreturn
erase intleftbracketindex
erase intrightbracketindex
end function
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检查iif语句中放在对应"( )"内的语句中的条件表达式、true表达式、false表达式
douhapy 2005-01-31
参数:
strsentence :任意一条语句（该语句含有iif）
strcondition :返回该iif语句中的条件表达式
strreturnt :返回该iif语句中的true表达式
strreturnf :返回该iif语句中的false表达式
返回值:
true 成功查找到所需的表达式
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function checkiifsentence(byval strsentence as string, optional byref strcondition as string = "", _
optional byref strreturnt as string = "", optional byref strreturnf as string = "") as boolean
dim strtmp as string
dim striifsentence as string
dim mstrcondition as string iif语句中的条件
dim mstrreturnt as string iif语句中的true结果
dim mstrreturnf as string iif语句中的false结果
dim inttmp1 as integer
dim inttmp2 as integer
dim i as integer
dim j as integer
dim m as integer
dim blsucceed as boolean
dim intleftbracketindex() as integer 所有左括号的位置
dim intrightbracketindex() as integer 所有右括号的位置
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先查找iif (,判断是否为iif语句
strtmp = replace(strsentence, " ", "")
if instr(1, strtmp, "iif(", vbtextcompare) = 0 then
exit function
end if
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获取iif中的表达式
strtmp = strsentence
inttmp1 = instr(1, strtmp, "iif", vbtextcompare)
if inttmp1 then
获取离iif最近的左括号的位置，并保存
inttmp1 = instr(inttmp1, strtmp, "(")
striifsentence = getclosestring(strtmp, inttmp1)
blsucceed = true
end if
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获取iif中的条件以及返回值
if blsucceed then
blsucceed = false
获取条件
inttmp1 = instr(1, striifsentence, ",", vbtextcompare)
if inttmp1 <> 0 then
mstrcondition = mid(striifsentence, 1, inttmp1 – 1)
inttmp2 = instr(inttmp1 + 1, striifsentence, ",", vbtextcompare)
if inttmp2 <> 0 then
获取返回值
mstrreturnt = mid(striifsentence, inttmp1 + 1, inttmp2 – inttmp1 – 1)
mstrreturnf = mid(striifsentence, inttmp2 + 1, len(striifsentence) – inttmp2)
blsucceed = true
end if
end if
end if
checkiifsentence = blsucceed
strcondition = mstrcondition
strreturnt = mstrreturnt
strreturnf = mstrreturnf
end function
private sub command1_click()
dim strtmp as string
dim strcondition as string iif语句中的条件
dim strreturnt as string iif语句中的true结果
dim strreturnf as string iif语句中的false结果
strtmp = "iif (((a+b)-(b+a))- ((b-6)-c) * a ,standout,outtime ) – (standout -outtime /2) > (standout + outtime)"
if checkiifsentence(strtmp, strcondition, strreturnt, strreturnf) then
msgbox "原语句:" & vbcrlf & strtmp & vbcrlf & _
"iif语句中的条件: " & strcondition & vbcrlf & vbcrlf & _
"iif语句中的true返回值: " & strreturnt & vbcrlf & _
"iif语句中的false返回值: " & strreturnf
msgbox getclosestring(strtmp, 57)
end if
strtmp = "{[[a123befgcb[[[["
msgbox getclosestring(strtmp, 4, "{[[a", "[[[[", false)
end sub
