设有如下通用过程:Public FunctionFun(x Str As String)As StringDimtStr As String,strL As Int

设有如下通用过程： Public FunctionFun(x Str As String)As String DimtStr As String，strL As Integer tStr="" strL=Len(xStr) i=1 DoWhilei＜=strL/2 tStr=tStr&Mid(xStr,i，1)&Mid(xStr,strL-i+1，1)" i=i+1 Loop Fun=tStr End Function 在窗体

A．ABCDEF

B．abcdef

C．AFBECD

D．DEFABC