通过GetProperty获得的marginRatio为什么是0？

代码如下： OnBar(ArrayRef<Integer> indexs) { String symbol_code = Symbol(); Print("MarginRatio: " + Text(MarginRatio())); CodeProperty prop; GetProperty(prop); Print("prop: " + Text(prop) + "\n--------"); }Print输出如下：MarginRatio: 0.11prop: symbol = i2509.DCE, bigCategory = 1, symbolName = 铁矿石2509, dealTimes = |21:00-23:00;09:00-10:15;10:30-11:30;13:30-15:00;|||||, decDigits = 1, priceScale = 0.100000, minMove = 5, contractUnit = 100, marginRatio = 0.000000, marginMode = 4, baseShares = 1, handShares = 1, incrementalShares = 1, currencyID = 0, bigPointValue = 1.000000, effectiveDateTime = 20240913.180000, expiredDateTime = 20250912.180000, openDateTime = 20240913.180000, timeZone = 4, symbolType = i, opType = 0, strikePrice = 0.000000--------