使用wxHaskell注入wxWigets事件循环的无窗口事件

Question

Haskell-way多线程和wxWidgets的另一个问题。

我看到https://stackoverflow.com/a/12596595/4095104作为一个很好的黑客运行在WX事件循环代码，但它需要我start/run首先要创建一个窗口，从它返回，因此事件循环可以自生自灭，而我的应用程序是基本上不需要窗口，并且可以根据内部（多线程）逻辑的需求创建窗口。有没有一种好的方法可以在循环中创建一个不绑定到任何已有的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++水平，你可以只使用wxEventLoop class直接，但我不知道它是否正确由wxHaskell包裹。