delphi Try except on e:Exception do

except on e:Exception do

//判断单位转换率

  try

    um_rate := vp_mstr.F('vp_um_rate_d').AsFloat / vp_mstr.F('vp_um_rate_m').AsFloat;

    if um_rate <= 0 then

      abort

    else if (vp_mstr.F('vp_um').AsString = vp_mstr.F('part_um').AsString) and (um_rate <> 1) then

      abort

    else if (vp_mstr.F('vp_um').AsString <> vp_mstr.F('part_um').AsString) and (um_rate = 1) then

      abort;

  except on e:Exception do

    begin

    Application.MessageBox(PChar(E.Message), 'error', 16);//抛出异常信息

    priMsg.ShowMsg('004');  //004=单位转换率设置错误!

    edt_vp_um_rate_d.SetFocus;

    abort;

    end;

  end;