multithreading - 使用 wxHaskell 将无窗口事件注入到 wxWigets 事件循环中

Question

另一个对 Haskell 方式的多线程和 wxWidgets 的看法。

我认为https://stackoverflow.com/a/12596595/4095104是在 wx 事件循环中运行代码的好方法，但它需要我首先在start/中创建一个窗口run并从中返回，以便事件循环可以运行它当然，虽然我的应用程序本质上是无窗口的，并且可以从内部（多线程）逻辑按需创建窗口。有没有一种好方法可以在循环中创建一个不绑定到任何预先存在的 wxWidgets 对象的新事件？

编辑：代码示例：

import Graphics.UI.WX as WX
import Graphics.UI.WXCore as WXCore
import Control.Concurrent

-- | cf. http://snipplr.com/view/17538/
myEventId :: Int
myEventId = WXCore.wxID_HIGHEST+100
    -- the custom event ID, avoid clash with Graphics.UI.WXCore.Types.varTopId

-- | the custom event is registered as a menu event
createMyEvent :: IO (WXCore.CommandEvent ())
createMyEvent =
   WXCore.commandEventCreate WXCore.wxEVT_COMMAND_MENU_SELECTED myEventId

registerMyEvent :: WXCore.EvtHandler a -> IO () -> IO ()
registerMyEvent win io =
   WXCore.evtHandlerOnMenuCommand win myEventId io


doesntwork = do
    handler <- newEmptyMVar
    start $ do
        app <- wxcAppGetApp
        event <- createMyEvent
        mvar <- newEmptyMVar
        registerMyEvent app $ do
            str <- takeMVar mvar
            putStrLn str
        putMVar handler (app, event, mvar)
    (app, event, mvar) <- takeMVar handler
    putMVar mvar "hack"
    WXCore.evtHandlerAddPendingEvent app event
    threadDelay 10000000000

works = do
    handler <- newEmptyMVar
    start $ do
        app <- wxcAppGetApp
        event <- createMyEvent
        mvar <- newEmptyMVar
        registerMyEvent app $ do
            str <- takeMVar mvar
            putStrLn str
        putMVar handler (app, event, mvar)
        putMVar mvar "hack"
        WXCore.evtHandlerAddPendingEvent app event
    (app, event, mvar) <- takeMVar handler
    threadDelay 10000000000

main = doesntwork

Answer 1

在 C++ 级别，您可以直接使用wxEventLoop 类，但我不知道它是否被 wxHaskell 正确包装。