vb中Trim(Right(Left(ValueOfString, End_Pos), End_Pos - begin_Pos + 1))什么意思

Trim(Right(Left(ValueOfString, End_Pos), End_Pos - begin_Pos + 1))
Right(Left(ValueOfString, End_Pos), End_Pos - begin_Pos + 1)
Left(ValueOfString, End_Pos)
a=Left(ValueOfString, End_Pos),a的值为在ValueOfString中从左边数End_Pos个字符，比如ValueOfString=" abcdef ghijklmnopqrstuvwxyz",End_Pos=8,a的值就是" abcdef "

b=Right(a,End_Pos - begin_Pos + 1),b的值为在a中从边数（End_Pos - begin_Pos + 1）个字符，假设begin_Pos=3，那么（End_Pos - begin_Pos + 1）=8-3+1=6,b=Right(a,6)=Right(" abcdef ",6)="bcdef "

c=trim(b),c的值就是b去掉两端的空格之后的值，c=trim("bcdef ")="bcdef"