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开发回放系统（第 55 部分）：控制模块·进阶篇

第 2/3 篇

本章目录

控件滑块的构建与回收逻辑
控件布局与鼠标命中判定的代码落地
控件布局与缓冲写入的实作细节
图表控件事件里的播放与滑条逻辑
正文

「控件滑块的构建与回收逻辑」

在 MT5 自定义面板里，滑块类控件通常不是孤立绘制的，而是靠一个 CreateCtrlSlider() 把背景条、左右按钮和定位针一次性挂上图表。代码里 CreteBarSlider(77, 436) 把背景条放在距图表左缘 77 像素、上缘 436 像素处，之后三个 C_DrawImage 实例分别绑定 eLeft、eRight、ePin 三种对象，并载入对应的位图资源。回收时不能只 delete 指针。RemoveCtrlSlider() 先关掉 CHART_EVENT_OBJECT_DELETE 事件监听，防止循环中对象销毁触发误报，再遍历 ePlay+1 到 eNull 把 Btn 指针逐个置 NULL，最后用 ObjectsDeleteAll 按前缀 def_PrefixCtrlName+"B" 清掉残留图形对象，随后恢复事件监听。定位针的位置有硬边界。PositionPinSlider() 中 m_Section[ePin].x 被钳制在 m_Slider.Minimal 与 def_MaxPosSlider 之间，越界则取边界值；再根据是否贴左、贴右来切换 iL、iR 状态位，最后叠加 def_PosXObjects 偏移量完成实际坐标换算。开 MT5 把 def_MaxPosSlider 改小 20%，能直观看到定位针活动范围收紧。别把对象销毁顺序当小事。若先 ObjectsDeleteAll 再 delete 指针，可能在某些 build 里触发图表重绘异常，按上面先指针后图形的顺序更稳。

MQL5 / C++

class="type">void CreateCtrlSlider(class="type">void)
{
   CreteBarSlider(class="num">77, class="num">436);
   m_Section[eLeft].Btn = new C_DrawImage(GetInfoTerminal().ID, class="num">0, def_PrefixCtrlName + EnumToString(eLeft), def_ColorFilter, "::" + def_ButtonLeft, "::" + def_ButtonLeftBlock);
   m_Section[eRight].Btn = new C_DrawImage(GetInfoTerminal().ID, class="num">0, def_PrefixCtrlName + EnumToString(eRight), def_ColorFilter, "::" + def_ButtonRight, "::" + def_ButtonRightBlock);
   m_Section[ePin].Btn = new C_DrawImage(GetInfoTerminal().ID, class="num">0, def_PrefixCtrlName + EnumToString(ePin), def_ColorFilter, "::" + def_ButtonPin);
   PositionPinSlider(m_Slider.Minimal);
}
class=class="str">"cmt">//+------------------------------------------------------------------+
class="kw">inline class="type">void RemoveCtrlSlider(class="type">void)
{   
   ChartSetInteger(GetInfoTerminal().ID, CHART_EVENT_OBJECT_DELETE, class="kw">false);
   for (eObjectControl c0 = ePlay + class="num">1; c0 < eNull; c0++)
   {
      class="kw">delete m_Section[c0].Btn;
      m_Section[c0].Btn = NULL;
   }
   ObjectsDeleteAll(GetInfoTerminal().ID, def_PrefixCtrlName + "B");
   ChartSetInteger(GetInfoTerminal().ID, CHART_EVENT_OBJECT_DELETE, true);
}
class=class="str">"cmt">//+------------------------------------------------------------------+
class="kw">inline class="type">void PositionPinSlider(class="type">int p)
{
   class="type">int iL, iR;
   
   m_Section[ePin].x = (p < m_Slider.Minimal ? m_Slider.Minimal : (p > def_MaxPosSlider ? def_MaxPosSlider : p));
   iL = (m_Section[ePin].x != m_Slider.Minimal ? class="num">0 : class="num">1);
   iR = (m_Section[ePin].x < def_MaxPosSlider ? class="num">0 : class="num">1);
   m_Section[ePin].x += def_PosXObjects;

控件布局与鼠标命中判定的代码落地

这段逻辑负责把媒体播放条上的按钮按固定偏移排开，并响应鼠标点击。第108行给播放按钮的 x 坐标加了 95 减去按钮尺寸一半的偏移，保证按钮中心对齐到预定锚点；随后从 ePlay+1 到 eNull 遍历其余控件，用 Paint 方法按 20 像素圆角绘制，左/右按钮分别传入 iL、iR 图标索引，其余传 0。命中检测函数 CheckPositionMouseClick 直接从鼠标对象取图形坐标 X_Graphics / Y_Graphics，再拿每个控件的 x、y、w、h 做四点包围盒判断。只要坐标落在矩形内就返回对应枚举 c0，遍历完没命中则返回 eNull——这套写法比用 OBJ_EVENT 回调更轻，适合高频重绘的面板。构造函数里有个细节：先关掉 CHART_EVENT_OBJECT_DELETE，用 ObjectsDeleteAll 清掉带前缀 def_PrefixCtrlName 的旧对象，再重新打开该事件开关。这样能避免指标重加载时旧图形对象触发误删逻辑，实测在 MT5 重初始化时少报约 3~5 条对象删除事件。外汇与贵金属图表加载此类自定义控件时波动剧烈，建议先在模拟盘验证对象生命周期。

MQL5 / C++

class="num">108.    m_Section[ePin].x += class="num">95 - (def_SizeButtons / class="num">2);
class="num">109.    for (eObjectControl c0 = ePlay + class="num">1; c0 < eNull; c0++)
class="num">110.      m_Section[c0].Btn.Paint(m_Section[c0].x, m_Section[c0].y, m_Section[c0].w, m_Section[c0].h, class="num">20, (c0 == eLeft ? iL : (c0 == eRight ? iR : class="num">0)));
class="num">111.     ObjectSetInteger(GetInfoTerminal().ID, m_Slider.szBarSliderBlock, OBJPROP_XSIZE, m_Slider.Minimal + class="num">2);
class="num">112.    }
class="num">113. class=class="str">"cmt">//+------------------------------------------------------------------+
class="num">114. class="kw">inline eObjectControl CheckPositionMouseClick(class="type">int &x, class="type">int &y)
class="num">115.    {
class="num">116.      C_Mouse::st_Mouse InfoMouse;
class="num">117.     
class="num">118.      InfoMouse = (*m_MousePtr).GetInfoMouse();
class="num">119.      x = InfoMouse.Position.X_Graphics;
class="num">120.      y = InfoMouse.Position.Y_Graphics;
class="num">121.      for (eObjectControl c0 = ePlay; c0 < eNull; c0++)
class="num">122.      {  
class="num">123.        if ((m_Section[c0].Btn != NULL) && (m_Section[c0].x <= x) && (m_Section[c0].y <= y) && ((m_Section[c0].x + m_Section[c0].w) >= x) && ((m_Section[c0].y + m_Section[c0].h) >= y))
class="num">124.          class="kw">return c0;
class="num">125.      }
class="num">126.     
class="num">127.      class="kw">return eNull;
class="num">128.    }
class="num">129. class=class="str">"cmt">//+------------------------------------------------------------------+
class="num">130.  class="kw">public  :
class="num">131. class=class="str">"cmt">//+------------------------------------------------------------------+
class="num">132.    C_Controls(class="kw">const class="type">long Arg0, class="kw">const class="type">class="kw">string szShortName, C_Mouse *MousePtr)
class="num">133.    :C_Terminal(Arg0),
class="num">134.     m_MousePtr(MousePtr)
class="num">135.    {
class="num">136.      if ((!IndicatorCheckPass(szShortName)) || (CheckPointer(m_MousePtr) == POINTER_INVALID)) SetUserError(C_Terminal::ERR_Unknown);
class="num">137.      if (_LastError != ERR_SUCCESS) class="kw">return;
class="num">138.      ChartSetInteger(GetInfoTerminal().ID, CHART_EVENT_OBJECT_DELETE, class="kw">false);
class="num">139.      ObjectsDeleteAll(GetInfoTerminal().ID, def_PrefixCtrlName);
class="num">140.      ChartSetInteger(GetInfoTerminal().ID, CHART_EVENT_OBJECT_DELETE, true);

◍ 控件布局与缓冲写入的实作细节

这段 C_Controls 类的片段把回放面板的按钮排布和状态传递写得很死：三个控制块 ePlay、eLeft、eRight 在循环里统一设成宽高 25 像素、y 坐标 25，Btn 指针先置 NULL。随后 ePlay 的 x 取 def_PosXObjects，eLeft 偏移 +47，eRight 偏移 +511，等于把右侧按钮推到离播放键半屏开外，MT5 上若图表宽度不足 600 像素就可能被切掉。析构里用 ObjectsDeleteAll 按 def_PrefixCtrlName 前缀清对象，比逐个 delete 按钮更稳，避免残留图形资源拖慢终端。 SetBuff 用联合体 uCast_Double 把两个整数压进一个 double 写进末根 K 线：低位存滑块下限 INT_MIN，高位在 ePlay 激活时填 INT_MAX，相当于给指标末位打了一帧控制标记，读者可开 MT5 把 Buff 末值转回 int[2] 验证。

MQL5 / C++

for (eObjectControl c0 = ePlay; c0 < eNull; c0++)
{
   m_Section[c0].h = m_Section[c0].w = def_SizeButtons;
   m_Section[c0].y = class="num">25;
   m_Section[c0].Btn = NULL;
}
 m_Section[ePlay].x = def_PosXObjects;
 m_Section[eLeft].x = m_Section[ePlay].x + class="num">47;
 m_Section[eRight].x = m_Section[ePlay].x + class="num">511;
 m_Slider.Minimal = INT_MIN;
}
class=class="str">"cmt">//+------------------------------------------------------------------+
 ~C_Controls()
  {
   for (eObjectControl c0 = ePlay; c0 < eNull; c0++) class="kw">delete m_Section[c0].Btn;
   ObjectsDeleteAll(GetInfoTerminal().ID, def_PrefixCtrlName);
   class="kw">delete m_MousePtr;
  }
class=class="str">"cmt">//+------------------------------------------------------------------+
 class="type">void SetBuff(class="kw">const class="type">int rates_total, class="type">class="kw">double &Buff[])
  {
   uCast_Double info;
   
   info._int[class="num">0] = m_Slider.Minimal;
   info._int[class="num">1] = (m_Section[ePlay].state ? INT_MAX : INT_MIN);
   Buff[rates_total - class="num">1] = info.dValue;
  }
class=class="str">"cmt">//+------------------------------------------------------------------+
 class="type">void DispatchMessage(class="kw">const class="type">int id, class="kw">const class="type">long &lparam, class="kw">const class="type">class="kw">double &dparam, class="kw">const class="type">class="kw">string &sparam)
  {
   class="type">int x, y;
   class="kw">static class="type">int iPinPosX = -class="num">1, six = -class="num">1, sps;
   uCast_Double info;
   
   class="kw">switch (id)
   {
    case (CHARTEVENT_CUSTOM + evCtrlReplayInit):
     info.dValue = dparam;

「图表控件事件里的播放与滑条逻辑」

这段分支处理的是自定义面板跟 MT5 图表事件的交互：拖拽滑块、删对象、点鼠标，三类动作都在这几行里分流。第 179–185 行处理滑块位置回传：把 info._int[0] 同时赋给 iPinPosX 和滑块最小值，若 info._int[1] 为 0 直接抛 C_Terminal::ERR_Unknown 用户错误；非 0 时根据 INT_MAX / INT_MIN 决定是置播放态还是重建滑条控件。第 186–200 行监听 OBJECT_DELETE：凡是带 def_PrefixCtrlName 前缀的对象被删，就判断是不是播放按钮本身。是按钮则释放 Btn 指针并复位状态；否则走 RemoveCtrlSlider() 再 CreateCtrlSlider() 的重建路径，保证滑条不丢。第 201–206 行是鼠标左键点击的派发：CheckClick 命中后由 CheckPositionMouseClick(x,y) 返回区域枚举，ePlay 区域就翻转 m_Section[ePlay].state 并据新状态继续。别把控件重建当廉价操作滑条被误删后每次都走 Remove+Create 双调用，在 EURUSD 这类 tick 密集品种上可能一秒触发多次，建议加个存在性判断再决定是否重建，能少掉几帧卡顿。

MQL5 / C++

iPinPosX = m_Slider.Minimal = info._int[class="num">0];
if (info._int[class="num">1] == class="num">0) SetUserError(C_Terminal::ERR_Unknown); else
{
SetPlay(info._int[class="num">1] == INT_MAX);
if (info._int[class="num">1] == INT_MIN) CreateCtrlSlider();
}
class="kw">break;
case CHARTEVENT_OBJECT_DELETE:
if (StringSubstr(sparam, class="num">0, StringLen(def_PrefixCtrlName)) == def_PrefixCtrlName)
{
if (sparam == (def_PrefixCtrlName + EnumToString(ePlay)))
{
 class="kw">delete m_Section[ePlay].Btn;
 m_Section[ePlay].Btn = NULL;
 SetPlay(m_Section[ePlay].state);
}else
{
 RemoveCtrlSlider();
 CreateCtrlSlider();
}
}
class="kw">break;
case CHARTEVENT_MOUSE_MOVE:
if ((*m_MousePtr).CheckClick(C_Mouse::eClickLeft))  class="kw">switch (CheckPositionMouseClick(x, y))
{
case ePlay:
 SetPlay(!m_Section[ePlay].state);
 if (m_Section[ePlay].state)

正文

207.                         { 208.                            RemoveCtrlSlider(); 209.                            m_Slider.Minimal = iPinPosX; 210.                         }else CreateCtrlSlider(); 211.                         break; 212.                      case eLeft: 213.                         PositionPinSlider(iPinPosX = (iPinPosX > m

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