Question

我正在使用PyQt5，我想根据用户在现有按钮上的点击来绘制文本。

文本直接显示在Qwidget上，我希望文本在单击按钮后立即显示。怎么做？

我的代码是这样的：

{-# OPTIONS_GHC -Wall #-}
{-# LANGUAGE DeriveFunctor #-}

module TestStateJLJ1  where

import Data.Functor.Identity
import Control.Monad

data LogS = LogS { stepS :: Int , logS :: [String] }
  deriving (Show)

initLogS :: LogS
initLogS = LogS 1 []

newtype StateT s m a
  = StateT { runStateT :: (s, LogS) -> m (Maybe a, s, LogS) }
  deriving (Functor)

instance (Monad m) => Applicative (StateT s m) where
  pure a = StateT $ \(s, l) -> return (Just a, s, l)
  (<*>) = ap
instance (Monad m) => Monad (StateT s m) where
  return = pure
  m >>= k = StateT $ \(s, l) -> do
    (maybeA, s', l') <- runStateT m (s, l)
    case maybeA of
      Nothing -> return (Nothing, s', l')
      Just a -> runStateT (k a) (s', l' {stepS = 1 + stepS l'})
  fail err = StateT $ \(s, l) -> return (Nothing, s, l { logS = err:logS l })

type State s = StateT s Identity

state :: (Monad m) => ((s, LogS) -> (Maybe a, s, LogS)) -> StateT s m a
state f = StateT $ return . f

Answer 1

首先，将文本设置为空：

self.text = ""

然后，创建按钮单击事件很重要：

self.btn1 = QPushButton("Button 1", self)
self.btn1.clicked.connect(self.button_click)

通过单击按钮创建要调用的函数：

def button_click(self):
    self.text = "Just For Test"
    self.repaint()

重新绘制将刷新您的QPaint

使用PyQt Painter绘图

1 个答案: