VB6总结VIII之常用函数function介绍

1. Mid(a,b,c)——获取字符串中包含的一部分字符串

a为原始字符串

b为从a的第几个字符开始获取

c为从a获取几个字符，c在省略的情况下默认为获取到a的最后一个字符

例如

Dim MyString, FirstWord, LastWord, MidWords
MyString = "Mid Function Demo"    ' Create text string.
FirstWord = Mid(MyString, 1, 3)    ' Returns "Mid".
LastWord = Mid(MyString, 14, 4)    ' Returns "Demo".
MidWords = Mid(MyString, 5)    ' Returns "Function Demo".

2. InStr(a,b,c,d)——返回字符串的特定字符个数

a为从b的第几个字符开始搜索特定字符，a省略的情况下默认为从第1个开始搜索特定字符

b为原始字符串

c为特定字符

d为返回类型，0返回二进制类型，1返回文本类型，d省略情况下默认为0

例如

Dim SearchString, SearchChar, MyPos
SearchString ="XXpXXpXXPXXP"    ' String to search in.
SearchChar = "P"    ' Search for "P".

' A textual comparison starting at position 4. Returns 6.
MyPos = Instr(4, SearchString, SearchChar, 1)    

' A binary comparison starting at position 1. Returns 9.
MyPos = Instr(1, SearchString, SearchChar, 0)

' Comparison is binary by default (last argument is omitted).
MyPos = Instr(SearchString, SearchChar)    ' Returns 9.

MyPos = Instr(1, SearchString, "W")    ' Returns 0.

结合了1和2的实例，如

Mid$(fgWhere.TextMatrix(intRow, 0), InStr(fgWhere.TextMatrix(intRow, 0), ".") + 1)

返回为

date_notification