如何通过Win32 API获取PowerBuilder中DataWindow及多行编辑控件句柄？

Great questions—let's break this down step by step, since PowerBuilder's windowing model has some unique quirks when working with Win32 APIs directly.

Absolutely. PowerBuilder wraps its DataWindow control around a standard Windows window, so you can retrieve its handle via Win32 calls, or even use PowerBuilder's built-in functions to make this easier:

• PowerBuilder-native shortcut: If you can run even a snippet of PB code, use the Handle() function directly (e.g., Handle(dw_your_datawindow) returns the underlying HWND). This is more reliable than pure Win32 APIs for PB-specific controls.
• Pure Win32 API approach: Use FindWindowEx() to locate the DataWindow within its parent window. PowerBuilder DataWindows use a class name that varies slightly by version—older PB versions use dwnd, while newer versions (PB 11+) use DataWindow. You'll need the parent window's HWND first (use FindWindow() if you know the main window's title/class), then call:

  HWND hwndDW = FindWindowEx(hwndParent, NULL, "DataWindow", NULL);
  

  If multiple DataWindows exist, filter by the control's title (you can set this in PB's DataWindow properties) by passing the title as the fourth parameter to FindWindowEx().

This is trickier, but doable—with a key caveat: PowerBuilder dynamically creates the embedded edit control only when the field is in edit mode (i.e., when the user clicks into the field to type). Here's how to get its handle:

1. First, get the DataWindow's HWND using the method above.
2. Trigger edit mode (if it's not already active): Send a WM_LBUTTONDOWN message to the DataWindow at the coordinates of the multiline edit field, followed by WM_LBUTTONUP to simulate a click. Alternatively, if you can run PB code, call dw_your_datawindow.SetFocus() and dw_your_datawindow.ScrollToRow(row) to activate the field.
3. Find the embedded edit control: Once the field is in edit mode, the multiline edit is a child window of the DataWindow. Use FindWindowEx() again, targeting the standard Win32 Edit class (PB uses standard edit controls for multiline fields, with the ES_MULTILINE style):

   HWND hwndMLE = FindWindowEx(hwndDW, NULL, "Edit", NULL);
   

   To confirm it's the multiline control, check its window style with GetWindowLongPtr(hwndMLE, GWL_STYLE) and verify the ES_MULTILINE flag is set.

For your custom operation goals #

Once you have these handles, you can absolutely modify default behavior via Win32 APIs:

• Subclass the control: Use SetWindowLongPtr() to replace the window procedure of the DataWindow or MLE, allowing you to intercept events like key presses, clicks, or focus changes. Just be sure to pass unhandled messages to the original procedure to avoid breaking PB's internal logic.
• Modify control properties: Send messages like EM_SETREADONLY to make the MLE read-only, EM_LIMITTEXT to restrict input length, or WM_SETFONT to change the font.
• Override default events: For example, intercept the WM_KEYDOWN message to disable the default Enter key behavior in the MLE, or add custom shortcut keys.

Just a heads-up: PowerBuilder's internal window management can be finicky, so test any API-based changes thoroughly across different PB versions and window states.

内容的提问来源于stack exchange，提问作者user7022367