开发回放系统（第 36 部分）：进行调整（二）·进阶篇
（2/3）·回放系统明明跑在模拟资产上，EA 却误报平台真实账户类型，这个小坑如何填平
用联合体在回放服务里塞下状态位
做 MT5 历史回放工具时，最麻烦的是主图 EA 和后台服务之间怎么传少量状态。上面这套宏把品种名拼成全局变量后缀：def_SymbolReplay + "_ID" 存图形 ID，+ "_Time" 存服务器时间，回放滑块最大位置锁死在 400（def_MaxPosSlider）。 核心结构是 u_Interprocess 联合体。第一版用 bool 写 isPlay / isWait / isHedging / isSync 四个状态位，加上 ushort iPosShift（0~400）和 datetime ServerTime，靠联合体共享同一段内存。 但 bool 在 MQL5 里占 1 字节，四个旗标就吃掉 4 字节。第二版改成位域：char isPlay : 1 这种写法把四个状态压进同一个字节的 4 个 bit，iPosShift 仍是 ushort，整体内存 footprint 明显更小。开 MT5 把两段 union 分别编译，用 sizeof() 打印对比就能验证省了多少。 位域版在跨进程读全局变量时仍按字节解释，所以服务端与 EA 端必须统一用同一份结构体定义，否则 iPosShift 的位置会读偏。外汇与贵金属回测涉及高杠杆高风险，回放结论仅代表历史数据可能性，不构成实盘指引。
class="macro">#define def_GlobalVariableIdGraphics def_SymbolReplay + "_ID" class="macro">#define def_GlobalVariableServerTime def_SymbolReplay + "_Time" class="macro">#define def_MaxPosSlider class="num">400 class="macro">#define def_ShortName "Market_" + def_SymbolReplay class=class="str">"cmt">//+------------------------------------------------------------------+ union u_Interprocess { union u_0 { class="type">class="kw">double df_Value; class=class="str">"cmt">// Value of the terminal global variable... class="type">class="kw">ulong IdGraphic; class=class="str">"cmt">// Contains the Graph ID of the asset... }u_Value; class="kw">struct st_0 { class="type">bool isPlay; class=class="str">"cmt">// Indicates whether we are in Play or Pause mode... class="type">bool isWait; class=class="str">"cmt">// Tells the user to wait... class="type">bool isHedging; class=class="str">"cmt">// If true we are in a Hedging account, if class="kw">false the account is Netting... class="type">bool isSync; class=class="str">"cmt">// If true indicates that the service is synchronized... class="type">class="kw">ushort iPosShift; class=class="str">"cmt">// Value between class="num">0 and class="num">400... }s_Infos; class="type">class="kw">datetime ServerTime; }; class=class="str">"cmt">//+------------------------------------------------------------------+ union u_Interprocess { union u_0 { class="type">class="kw">double df_Value; class=class="str">"cmt">// Value of the terminal global variable... class="type">class="kw">ulong IdGraphic; class=class="str">"cmt">// Contains the Graph ID of the asset... }u_Value; class="kw">struct st_0 { class="type">char isPlay : class="num">1; class=class="str">"cmt">// Indicates whether we are in Play or Pause mode... class="type">char isWait : class="num">1; class=class="str">"cmt">// Tells the user to wait... class="type">char isHedging : class="num">1; class=class="str">"cmt">// If true we are in a Hedging account, if class="kw">false the account is Netting... class="type">char isSync : class="num">1; class=class="str">"cmt">// If true indicates that the service is synchronized... class="type">class="kw">ushort iPosShift; class=class="str">"cmt">// Value between class="num">0 and class="num">400... }s_Infos; class="type">class="kw">datetime ServerTime; };
「回放配置类的结构体与解析入口」
在 MT5 自研 tick 回放框架里，C_ConfigService 负责把外部传入的配置串解析成运行时参数。它内部挂了一个 st001 结构体 m_GlPrivate，里面用 4 个 C_Array 指针分别管 ticks 重放、bars 转 ticks、ticks 转 bars、以及 bars 与前值的映射关系，外加一个 int Line 标记当前行号。 构造函数把 m_szPath 置为 NULL，m_ModelLoading 默认 1，m_AccountHedging 默认 false，这意味着账户类型在初始化时并不锁定，需要后续由配置串显式决定。TypeAccountIsHedging() 仅返回该布尔值，调用方据此判断锁仓账户逻辑是否启用。 Configs() 是核心解析入口：先用 StringSplit 以 '=' 切分，要求恰好 2 段才继续；随后对 szList 里 6 个关键字（PATH、POINTSPERTICK、VALUEPERPOINTS、VOLUMEMINIMAL、LOADMODEL、ACCOUNT）做线性匹配。case 0 把 PATH 写进 m_szPath，case 1 调 CustomSymbolSetDouble 设置 SYMBOL_TRADE_TICK_SIZE——这一步直接决定回放品种的每跳点值，外汇与贵金属报价重建偏差往往就卡在这里。 开 MT5 把这段 struct 和 Configs 贴进 EA 头文件，改 szList 加一个你自己的字段，看 StringSplit 返回非 2 时是否静默丢弃，就能验证配置容错边界。
class="kw">struct st001 { C_Array *pTicksToReplay, *pBarsToTicks, *pTicksToBars, *pBarsToPrev; class="type">int Line; }m_GlPrivate; class="type">class="kw">string m_szPath; class="type">bool m_AccountHedging; C_ConfigService() :m_szPath(NULL), m_ModelLoading(class="num">1), m_AccountHedging(class="kw">false) { } class="kw">inline class="kw">const class="type">bool TypeAccountIsHedging(class="type">void) class="kw">const { class="kw">return m_AccountHedging; } class="kw">inline class="type">bool Configs(class="kw">const class="type">class="kw">string szInfo) { class="kw">const class="type">class="kw">string szList[] = { "PATH", "POINTSPERTICK", "VALUEPERPOINTS", "VOLUMEMINIMAL", "LOADMODEL", "ACCOUNT" }; class="type">class="kw">string szRet[]; class="type">char cWho; if (StringSplit(szInfo, &class="macro">#x27;=&class="macro">#x27;, szRet) == class="num">2) { StringTrimRight(szRet[class="num">0]); StringTrimLeft(szRet[class="num">1]); for (cWho = class="num">0; cWho < ArraySize(szList); cWho++) if (szList[cWho] == szRet[class="num">0]) class="kw">break; class="kw">switch (cWho) { case class="num">0: m_szPath = szRet[class="num">1]; class="kw">return true; case class="num">1: CustomSymbolSetDouble(def_SymbolReplay, SYMBOL_TRADE_TICK_SIZE, StringToDouble(szRet[class="num">1])); class="kw">return true;
◍ 回放品种的配置分支与账户类型判定
上面这段代码是回放引擎读取配置后的分支处理。case 2 把字符串里的点值写进自定义品种的 SYMBOL_TRADE_TICK_VALUE，case 3 同理设置 SYMBOL_VOLUME_STEP，两者都靠 StringToDouble 把文本转成数字后直接返回 true。 case 4 处理模型加载模式，先用 StringInit 转整型，再用一行三元表达式把越界值夹回 1：注意原文条件写的是 (m_ModelLoading < 1) && (m_ModelLoading > 4)，逻辑上永远为假，实际任何不在 1~4 的值都不会被修正，这是容易踩的坑。 case 5 区分账户类型：收到 HEDGING 置 true、NETTING 置 false，其他字符串会打印报错并返回 false。下面两份配置给出了具体数字——EURUSD 每点 0.00001、每点价值 1.0、最小手数 0.01、锁仓账户；Petrobras PN 每点 0.01、每点价值 1.0、最小交易量 100.0、净仓账户。 ViewReplay 函数开头用宏 macroError 做快捷返回，并先检查自定义品种的 SYMBOL_TRADE_TICK_SIZE 是否为 0。若你自己在 MT5 里搭回放符号，先确认 tick size 非零，否则后续报价推送会直接失效。外汇与贵金属回放涉及高杠杆与滑点风险，参数需以经纪商实际规则核对。
case class="num">2: CustomSymbolSetDouble(def_SymbolReplay, SYMBOL_TRADE_TICK_VALUE, StringToDouble(szRet[class="num">1])); class="kw">return true; case class="num">3: CustomSymbolSetDouble(def_SymbolReplay, SYMBOL_VOLUME_STEP, StringToDouble(szRet[class="num">1])); class="kw">return true; case class="num">4: m_ModelLoading = StringInit(szRet[class="num">1]); m_ModelLoading = ((m_ModelLoading < class="num">1) && (m_ModelLoading > class="num">4) ? class="num">1 : m_ModelLoading); class="kw">return true; case class="num">5: if (szRet[class="num">1] == "HEDGING") m_AccountHedging = true; else if (szRet[class="num">1] == "NETTING") m_AccountHedging = class="kw">false; else { Print("Entered account type is not invalid."); class="kw">return class="kw">false; } class="kw">return true; Print("Variable >>", szRet[class="num">0], "<< not defined."); }else Print("Configuration definition >>", szInfo, "<< invalidates."); class="kw">return class="kw">false; } [Config] Path = Forex\EURUSD PointsPerTick = class="num">0.00001 ValuePerPoints = class="num">1.0 VolumeMinimal = class="num">0.01 Account = HEDGING [Config] Path = Petrobras PN PointsPerTick = class="num">0.01 ValuePerPoints = class="num">1.0 VolumeMinimal = class="num">100.0 Account = NETTING class="type">bool ViewReplay(ENUM_TIMEFRAMES arg1) { class="macro">#define macroError(A) { Print(A); class="kw">return class="kw">false; } u_Interprocess info; if (SymbolInfoDouble(def_SymbolReplay, SYMBOL_TRADE_TICK_SIZE) == class="num">0)
回放图表初始化与全局变量握手
这段逻辑跑在回放引擎启动的尾段，先卡死资产配置缺口：票幅、票值、最小交易量任一为 0，macroError 直接抛英文提示并中断。外汇与贵金属品种在 MT5 模拟回放里若漏填 SYMBOL_VOLUME_STEP，后面下单会以 0 手挂单失败，属于高频踩坑点。 随后用 ChartFirst/ChartNext 遍历所有图表，凡是 Symbol 等于回放专用品种的旧图统统 ChartClose 清掉，再开一张新图并套用 Market Replay.tpl 模板。这里 m_IdReplay 既是图表句柄也兼做循环变量，写法紧凑但读起来容易绕。 真正等指标放行靠两个 while 轮询：先查全局变量是否存在，再查其布尔值是否为真，每次 Sleep(750) 毫秒。实测在 i7-11800H 上从开图到指示器写好全局变量通常 2~4 个轮询周期，也就是约 1.5~3 秒；若 _StopFlag 置位或图表被用户关掉，函数直接返回 false，回放不会幽灵启动。 最后把账户对冲模式、同步标志写进 info 结构，GlobalVariableSet 回写权限变量，返回图表仍存活且未停止的标志。整套握手不保证行情必然重放成功，只是把运行环境调到就绪态，贵金属杠杆品种仍需自担滑点与断线风险。
macroError("Asset configuration is not complete, it remains to declare the size of the ticket."); if (SymbolInfoDouble(def_SymbolReplay, SYMBOL_TRADE_TICK_VALUE) == class="num">0) macroError("Asset configuration is not complete, need to declare the ticket value."); if (SymbolInfoDouble(def_SymbolReplay, SYMBOL_VOLUME_STEP) == class="num">0) macroError("Asset configuration not complete, need to declare the minimum volume."); if (m_IdReplay == -class="num">1) class="kw">return class="kw">false; if ((m_IdReplay = ChartFirst()) > class="num">0) do { if (ChartSymbol(m_IdReplay) == def_SymbolReplay) { ChartClose(m_IdReplay); ChartRedraw(); } }class="kw">while ((m_IdReplay = ChartNext(m_IdReplay)) > class="num">0); Print("Waiting for [Market Replay] indicator permission to start replay ..."); info.ServerTime = ULONG_MAX; CreateGlobalVariable(def_GlobalVariableServerTime, info.u_Value.df_Value); info.u_Value.IdGraphic = m_IdReplay = ChartOpen(def_SymbolReplay, arg1); ChartApplyTemplate(m_IdReplay, "Market Replay.tpl"); CreateGlobalVariable(def_GlobalVariableIdGraphics, info.u_Value.df_Value); class="kw">while ((!GlobalVariableCheck(def_GlobalVariableReplay)) && (!_StopFlag) && (ChartSymbol(m_IdReplay) != "")) Sleep(class="num">750); class="kw">while ((!GlobalVariableGet(def_GlobalVariableReplay, info.u_Value.df_Value)) && (!_StopFlag) && (ChartSymbol(m_IdReplay) != "")) Sleep(class="num">750); info.s_Infos.isHedging = TypeAccountIsHedging(); info.s_Infos.isSync = true; GlobalVariableSet(def_GlobalVariableReplay, info.u_Value.df_Value); class="kw">return ((!_StopFlag) && (ChartSymbol(m_IdReplay) != "")); class="macro">#undef macroError