如何在PyQt5中跨屏幕移动一个点？

Question

我试图使用PyQt5在屏幕上移动一个点。我希望这一点始终是动人的。我不知道在哪里放置代码来改变它的速度。是否有一些方法的代码不断执行？

这是我的代码：

import sys
from PyQt5.QtWidgets import (QApplication, QLabel, QWidget)
from PyQt5.QtGui import QPainter, QColor, QPen
from PyQt5.QtCore import Qt

class MouseTracker(QWidget):
    distance_from_target = 0
    mouse_x_pos = 0
    mouse_y_pos = 0
    target_x_pos = 500
    target_y_pos = 250

    def __init__(self):
        super().__init__()
        self.initUI()
        self.setMouseTracking(True)

    def initUI(self):
        self.setGeometry(200, 200, 1000, 500)
        self.setWindowTitle('Mouse Tracker')
        self.label = QLabel(self)
        self.label.resize(500, 40)
        self.show()

    def mouseMoveEvent(self, event):
        distance_from_target = round(((event.y() - self.target_y_pos)**2 + (event.x() - self.target_x_pos)**2)**0.5)
        self.label.setText('Coordinates: (%d : %d)' % (event.x(), event.y()) + "   Distance from target: " + str(distance_from_target))       
        self.mouse_x_pos = event.x()
        self.mouse_y_pos = event.y()
        self.update()

    def mousePressEvent(self, event):
        self.target_x_pos = event.x()
        self.target_y_pos = event.y()
        self.update()

    def paintEvent(self, event):
        q = QPainter()
        q.begin(self)
        q.drawLine(self.mouse_x_pos, self.mouse_y_pos, self.target_x_pos, self.target_y_pos)

app = QApplication(sys.argv)
ex = MouseTracker()
sys.exit(app.exec_())

我想做的是让target_x_pos不断增加，无论鼠标是移动还是点击。我该怎么做？

我无法实现循环，因为其他任何东西都不会响应。这是线程进入的地方吗？

Answer 1

您只需实施QTimer，每次触发时，除了使用self.update()更新图纸外，还必须更新所需的位置。

import sys

from PyQt5.QtCore import QTimer
from PyQt5.QtWidgets import (QApplication, QLabel, QWidget)
from PyQt5.QtGui import QPainter


class MouseTracker(QWidget):
    distance_from_target = 0
    mouse_x_pos = 0
    mouse_y_pos = 0
    target_x_pos = 500
    target_y_pos = 250
    vel = 60  # pixels per second

    def __init__(self, parent=None):
        super(MouseTracker, self).__init__(parent=parent)
        self.initUI()
        self.setMouseTracking(True)
        self.timer = QTimer(self)
        self.timer.timeout.connect(self.changePosition)
        self.timer.start(1000 / self.vel)

    def changePosition(self):
        self.target_x_pos += 1
        self.update()

    def initUI(self):
        self.setGeometry(200, 200, 1000, 500)
        self.setWindowTitle('Mouse Tracker')
        self.label = QLabel(self)
        self.label.resize(500, 40)
        self.show()

    def mouseMoveEvent(self, event):
        distance_from_target = round(
            ((event.y() - self.target_y_pos) ** 2 + (event.x() - self.target_x_pos) ** 2) ** 0.5)
        self.label.setText(
            'Coordinates: (%d : %d)' % (event.x(), event.y()) + "   Distance from target: " + str(distance_from_target))
        self.mouse_x_pos = event.x()
        self.mouse_y_pos = event.y()
        self.update()

    def mousePressEvent(self, event):
        self.target_x_pos = event.x()
        self.target_y_pos = event.y()
        self.update()

    def paintEvent(self, event):
        q = QPainter()
        q.begin(self)
        q.drawLine(self.mouse_x_pos, self.mouse_y_pos, self.target_x_pos, self.target_y_pos)


app = QApplication(sys.argv)
w = MouseTracker()
sys.exit(app.exec_())

如果你想用Thread测试我给你看下面的代码，我在刷新值时没有遇到任何问题。

import sys
import time
from PyQt5.QtCore import QThread
from PyQt5.QtCore import QTimer
from PyQt5.QtCore import pyqtSignal
from PyQt5.QtWidgets import (QApplication, QLabel, QWidget)
from PyQt5.QtGui import QPainter


class MyThread(QThread):
    signal = pyqtSignal(int)

    def __init__(self, parent=None):
        super(MyThread, self).__init__(parent=parent)
        self.value = None
        self.vel = None

    def setValue(self, value):
        self.value = value

    def setVelocity(self, vel):
        self.vel = vel

    def run(self):
        while True:
            self.value += 1
            self.signal.emit(self.value)
            time.sleep(1/self.vel)


class MouseTracker(QWidget):
    distance_from_target = 0
    mouse_x_pos = 0
    mouse_y_pos = 0
    target_x_pos = 500
    target_y_pos = 250
    vel = 60  # pixels per second

    def __init__(self, parent=None):
        super(MouseTracker, self).__init__(parent=parent)
        self.initUI()
        self.setMouseTracking(True)
        self.thread = MyThread(self)
        self.thread.setValue(self.target_x_pos)
        self.thread.setVelocity(self.vel)
        self.thread.signal.connect(self.updatePosition)
        self.thread.start()

    def updatePosition(self, val):
        self.target_x_pos = val
        self.update()

    def initUI(self):
        self.setGeometry(200, 200, 1000, 500)
        self.setWindowTitle('Mouse Tracker')
        self.label = QLabel(self)
        self.label.resize(500, 40)
        self.show()

    def mouseMoveEvent(self, event):
        distance_from_target = round(
            ((event.y() - self.target_y_pos) ** 2 + (event.x() - self.target_x_pos) ** 2) ** 0.5)
        self.label.setText(
            'Coordinates: (%d : %d)' % (event.x(), event.y()) + "   Distance from target: " + str(distance_from_target))
        self.mouse_x_pos = event.x()
        self.mouse_y_pos = event.y()
        self.update()

    def mousePressEvent(self, event):
        self.target_x_pos = event.x()
        self.thread.setValue(self.target_x_pos)
        self.target_y_pos = event.y()
        self.update()

    def paintEvent(self, event):
        q = QPainter()
        q.begin(self)
        q.drawLine(self.mouse_x_pos, self.mouse_y_pos, self.target_x_pos, self.target_y_pos)


app = QApplication(sys.argv)
w = MouseTracker()
sys.exit(app.exec_())