在另一个应用程序的窗口中显示一个弹出菜单

Question

How can a Delphi XE application show a popup menu inside another application's window? The idea is for a helper-type app, running in the background. On a registered hotkey the application needs to display a popup menu near the text caret or mouse cursor.

Applications that do that are common, here's a menu created by AutoHotkey and displayed in a text editor:

I guess what I'm asking is: how can I display a popup menu at an arbitrary screen location, without it being attached to a Delphi control?

Answer 1

Create a TPopupMenu with the appropriate menu items. When you need to show it simply call Popup passing the top left position in screen coordinates.

PopupMenu1.Popup(X, Y);

Answer 2

@DavidHeffernan answered your question, but you might not have asked the right question.

Let's take the example you gave: the user is running some arbirary application, and you want to be able to detect a hotkey, display a menu, and then take some action based on the menu item chosen (and maybe even the user's context, such as the word under the cursor). This is more complicated than simply displaying a menu at arbitrary screen coordinates.

My recommendation is to use AutoHotKey instead of trying to replicate this in some other programming language. In case you're not aware of this, it is possible for your code to run AutoHotKey scripts. IIRC, you can compile AHK scripts, so you wouldn't need to install AHK, just the compiled scripts. AHK may not be the most elegant of solutions, but it has depth and maturity.

If this is not possible, then I suggest you research Windows Hooks and DLL Injection. Unless you can find some preexisting code or framework, this will entail quite a bit of work.

The reason for this complexity? To augment another program smoothly (without running into problems with focus, etc.) you want to have your code run as part of that other program. The mechanics of this can be done via DLL injection. However, that's only the first step. Once your code is running in the right context, then your code has to inter-operate with the "host" program. This can be tricky (it helps if you have deep experience with Windows messaging and the Windows API). If you want this to work smoothly with any arbitrary program, it gets even harder.