求助：如何通过MQL4读取MT4一键交易中的手数数值

我需要通过MQL4获取MT4一键交易界面中的手数（对应界面内的手数输入框）。目前已导入user32.dll相关函数并编写了获取逻辑，能定位到承载手数的Edit控件句柄，但使用GetWindowTextW和SendMessageW(WM_GETTEXT)均无法读取其中文本；另外，定位依赖的Afx类名在重启MT4后会发生变化，请求技术协助解决这两个问题。

已导入的user32.dll代码 #

#import "user32.dll"
   int FindWindowW(string className, string windowName);
   int FindWindowExW(int hwndParent, int hwndChildAfter, string className, string windowName);
   int GetWindowTextW(int hWnd, string lpString, int nMaxCount);
   int GetParent(int hWnd);
   int SendMessageW(int hWnd, int Msg, int wParam, string lParam);
#import

当前手数获取函数 #

double GetLotSizeFromOneClickTrading()
{
   int hwndMT4 = FindWindowW("MetaQuotes::MetaTrader::4.00", NULL);
   if (hwndMT4 == 0)
      return -1;

   int hwndMDIClient = FindWindowExW(hwndMT4, 0, "MDIClient", NULL);
   if (hwndMDIClient == 0)
      return -2;

   int hwndAboveChart = FindWindowExW(hwndMDIClient, 0, "Afx:00610000:b:00010003:00000006:000715CD", NULL);
   if (hwndAboveChart == 0)
      return -3;

   int hwndChart = FindWindowExW(hwndAboveChart, 0, "AfxFrameOrView140s", NULL);
   if (hwndChart == 0)
      return -4;

   int hwndEdit = FindWindowExW(hwndChart, 0, "Edit", NULL);
   if (hwndEdit == 0)
      return -5;

   // Get the lot size text from the edit box
   string lotSizeText;
   GetWindowTextW(hwndEdit, lotSizeText, 31);

   // Convert the text to a double and return it
   return StringToDouble(lotSizeText);

}

问题细节 #

• 定位使用的Afx:00610000:b:00010003:00000006:000715CD类名，重启MT4后会动态变化，该类名由WinSpy++获取
• 已确认hwndEdit为目标Edit控件的句柄，但以下两种文本读取方式均无效：

方式1：使用GetWindowTextW #

// Get the lot size text from the edit box
   string lotSizeText;
   GetWindowTextW(hwndEdit, lotSizeText, 31);

方式2：使用SendMessageW(WM_GETTEXT) #

// Get the lot size text from the edit box
   string lotSizeText;
   const int WM_GETTEXT = 0x000D;
   SendMessageW(hwndEdit, WM_GETTEXT, 31, lotSizeText);

内容的提问来源于stack exchange，提问作者Sahil Bagdi