调用 getDomInfo('brdh',WSC_virIdCardVerify,authKey);

说明：brdh 要取的节点字段，WSC_virIdCardVerify 要解析的xml字符串，authKey 返回值。

function  TForm1.getDomInfo(const a: string;info:string;var strb:string): string;
var
   head_begin,head_end,head_end1:Integer;
   authKey1,authKey: string;
begin
   head_begin := Pos(a+'>',info);
    head_end := Pos('</'+a,info);
    //showMessage(IntToStr(head_begin));
    //showMessage(IntToStr(head_end));
    authKey1 := copy(info,head_begin,head_end-head_begin);
    head_end1 := pos('>',authKey1);
    authKey := Copy(authKey1,head_end1+1,head_end-head_begin);
    //showMessage(authKey);
    Result := authKey;
    {authKey1 := copy(WSC_getAuthKey,head_begin,48);
    head_end1 := pos('>',authKey1);
    authKey := Copy(authKey1,9,48);
    result := authKey;
    showMessage(authKey);}

end;