[Mod] update gateway document for using ConId as contract symbol at IB Gateway

docs/gateway.md

@@ -72,7 +72,7 @@ def main():
 ## 接口分类
 
 | 接口     |                    类型                    |
-| ------ | :------: | 
+| -------- | :----------------------------------------: |
 | CTP      |                    期货                    |
 | FEMAS    |                    期货                    |
 | OES      |                  国内股票                  |
@@ -270,8 +270,11 @@ main_engine.add_gateway(IbGateway)
  
 
 #### 其他特点
+
 可交易品种几乎覆盖全球的股票、期权、期权；手续费相对较低。
 
+注意IB接口的合约代码较为特殊，请前往官网的产品查询板块查询，VN Trader中使用的是盈透证券对于每个合约在某一交易所的唯一标识符ConId来作为合约代码，而非Symbol或者LocalName。
+
  
 
 

tests/trader/run.py

@@ -5,7 +5,7 @@ from vnpy.trader.ui import MainWindow, create_qapp
 
 # from vnpy.gateway.bitmex import BitmexGateway
 # from vnpy.gateway.futu import FutuGateway
-# from vnpy.gateway.ib import IbGateway
+from vnpy.gateway.ib import IbGateway
 # from vnpy.gateway.ctp import CtpGateway
 # # from vnpy.gateway.ctptest import CtptestGateway
 # from vnpy.gateway.femas import FemasGateway
@@ -18,7 +18,7 @@ from vnpy.trader.ui import MainWindow, create_qapp
 # from vnpy.gateway.okexf import OkexfGateway
 # from vnpy.gateway.xtp import XtpGateway
 # from vnpy.gateway.hbdm import HbdmGateway
-from vnpy.gateway.tap import TapGateway
+# from vnpy.gateway.tap import TapGateway
 
 # from vnpy.app.cta_strategy import CtaStrategyApp
 # from vnpy.app.csv_loader import CsvLoaderApp
@@ -39,7 +39,7 @@ def main():
     # main_engine.add_gateway(CtpGateway)
     # # main_engine.add_gateway(CtptestGateway)
     # main_engine.add_gateway(FemasGateway)
-    # main_engine.add_gateway(IbGateway)
+    main_engine.add_gateway(IbGateway)
     # main_engine.add_gateway(FutuGateway)
     # main_engine.add_gateway(BitmexGateway)
     # main_engine.add_gateway(TigerGateway)
@@ -50,7 +50,7 @@ def main():
     # main_engine.add_gateway(OnetokenGateway)
     # main_engine.add_gateway(OkexfGateway)
     # main_engine.add_gateway(HbdmGateway)
-    main_engine.add_gateway(TapGateway)
+    # main_engine.add_gateway(TapGateway)
 
     # main_engine.add_app(CtaStrategyApp)
     # main_engine.add_app(CtaBacktesterApp)

vnpy/gateway/ib/ib_gateway.py

@@ -416,6 +416,9 @@ class IbApi(EWrapper):
             accountName,
         )
 
+        if not contract.exchange:
+            return
+
         ib_size = contract.multiplier
         if not ib_size:
             ib_size = 1