exchange.GetTicker

获取当前设置的交易对、合约代码对应的{@struct/Ticker Ticker}结构，即行情数据。GetTicker()函数是交易所对象{@var/EXCHANGE exchange}的成员函数，exchange对象的成员函数（方法）仅用于与exchange相关的操作，后续文档将不再重复说明。

{@struct/Ticker Ticker} / 空值

exchange.GetTicker()
exchange.GetTicker(symbol)

参数```symbol```用于指定请求的{@struct/Ticker Ticker}数据对应的合约代码。未传递该参数时，默认请求当前设置的合约代码的行情数据。
symbol
false
string

```javascript
function main(){
    // 鉴于测试代码，不使用商品期货策略的通用架构，这里仅判断exchange.IO("status")函数，确认连接期货公司前置机成功后立即执行测试代码。股票证券无需使用exchange.IO("status")判断连接状态
    while(!exchange.IO("status")) {
        Sleep(1000)
    }
    Log(exchange.SetContractType("rb888"))

    var ticker = exchange.GetTicker()
    Log("Symbol:", ticker.Symbol, "High:", ticker.High, "Low:", ticker.Low, "Sell:", ticker.Sell, "Buy:", ticker.Buy, "Last:", ticker.Last, "Open:", ticker.Open, "Volume:", ticker.Volume)
}```
```python
def main():
    while not exchange.IO("status"):
        Sleep(1000)
    Log(exchange.SetContractType("rb888"))

    ticker = exchange.GetTicker()
    Log("Symbol:", ticker["Symbol"], "High:", ticker["High"], "Low:", ticker["Low"], "Sell:", ticker["Sell"], "Buy:", ticker["Buy"], "Last:", ticker["Last"], "Open:", ticker.Open, "Volume:", ticker["Volume"])```
```cpp
void main() {
    while(exchange.IO("status") == 0) {
        Sleep(1000);
    }
    Log(exchange.SetContractType("rb888"));

    auto ticker = exchange.GetTicker();
    Log("Symbol:", ticker.Symbol, "High:", ticker.High, "Low:", ticker.Low, "Sell:", ticker.Sell, "Buy:", ticker.Buy, "Last:", ticker.Last, "Open:", ticker.Open, "Volume:", ticker.Volume);
}```
测试```exchange.GetTicker()```函数：

回测系统中```exchange.GetTicker()```函数返回的```Ticker```数据，其中```High```、```Low```为模拟值，取自当时盘口的卖一价、买一价。
商品期货策略实盘中，如果没有行情推送过来，exchange.GetTicker()函数会阻塞并等待行情推送。```exchange.GetDepth()```、```exchange.GetTrades()```、```exchange.GetRecords()```同理。如果不希望阻塞，可以使用以下方式切换行情模式：

- exchange.IO("mode", 0)
  立即返回模式：如果当前还没有接收到交易所最新的行情数据推送，则立即返回旧的行情数据；如果有新的数据则返回新的数据。
- exchange.IO("mode", 1)
  缓存模式（默认模式）：如果当前还没有收到交易所最新的行情数据（与上一次接口获取的数据比较），则等待接收后再返回；如果调用该函数之前已收到最新的行情数据，则立即返回最新的数据。
- exchange.IO("mode", 2)
  强制更新模式：进入等待状态，直到接收到交易所下一次的最新推送数据后返回。
实盘交易时（非回测模式），```exchange.GetTicker()```函数返回值中的```Info```属性存储了接口调用时返回的原始数据。

- 商品期货
  返回商品期货CTP协议/易盛协议接口的应答数据，以CTP协议为例：
  ```json
  {
      "BidPrice4": 1.7976931348623157e+308,
      "AskVolume4": 0,
      "AskVolume5": 0,
      "Turnover": 26229625880,
      "OpenInterest": 1364847,                  // 持仓量
      "ClosePrice": 1.7976931348623157e+308,
      "LowerLimitPrice": 3473,
      "BidPrice3": 1.7976931348623157e+308,
      "ExchangeID": "",
      "BidPrice2": 1.7976931348623157e+308,
      "BidPrice5": 1.7976931348623157e+308,
      "AveragePrice": 37323.89130239898,
      "BidVolume4": 0,
      "BidVolume5": 0,
      "ExchangeInstID": "",
      "LowestPrice": 3715,
      "Volume": 702757,
      "BidVolume3": 0,
      "AskPrice3": 1.7976931348623157e+308,
      "AskVolume3": 0,
      "ActionDay": "20200714",
      "PreClosePrice": 3739,
      "SettlementPrice": 1.7976931348623157e+308,
      "UpdateTime": "13:40:01",
      "BidPrice1": 3727,
      "AskPrice2": 1.7976931348623157e+308,
      "UpperLimitPrice": 3996,
      "CurrDelta": 1.7976931348623157e+308,
      "UpdateMillisec": 500,
      "AskVolume1": 154,
      "BidVolume2": 0,
      "PreOpenInterest": 1372843,
      "PreDelta": 0,
      "AskPrice1": 3728,
      "AskVolume2": 0,
      "TradingDay": "20200714",
      "InstrumentID": "rb2010",
      "LastPrice": 3727,
      "HighestPrice": 3749,
      "BidVolume1": 444,
      "PreSettlementPrice": 3735,
      "OpenPrice": 3740,
      "AskPrice4": 1.7976931348623157e+308,
      "AskPrice5": 1.7976931348623157e+308
  }

{@fun/Market/exchange.GetDepth exchange.GetDepth}, {@fun/Market/exchange.GetTrades exchange.GetTrades}, {@fun/Market/exchange.GetRecords exchange.GetRecords}