哎！
没办法！谁个熟手可否指点指点呀！
虽然有msdn但是不太理解：（copy from MSDNSetSel( cr ) This form uses the CHARRANGE structure
with its cpMin and cpMax members to set the bounds. SetSel( nStartChar, nEndChar ) This form use the parameters
nStartChar and nEndChar to set the bounds
没办法！谁个熟手可否指点指点呀！
虽然有msdn但是不太理解：（copy from MSDNSetSel( cr ) This form uses the CHARRANGE structure
with its cpMin and cpMax members to set the bounds. SetSel( nStartChar, nEndChar ) This form use the parameters
nStartChar and nEndChar to set the bounds
SetSel(5,30)或者SetSel(MAKELONG(5,30));选取所有字符
SetSel(0,-1)或SetSel(MAKELONG(0,-1));
取消所有选取
SetSel(-1,9)或SetSel(MAKELONG(-1,2002))