Python 如何在PyQt5中通过拖放绘制矩形并调整其形状
我试图通过拖放在PyQt5创建的GUI上绘制一个矩形。我设法做到了这一点,但是当鼠标左键被释放时,矩形就被画出来了 我想做的是这样:Python 如何在PyQt5中通过拖放绘制矩形并调整其形状,python,pyqt,pyqt5,qpainter,qmouseevent,Python,Pyqt,Pyqt5,Qpainter,Qmouseevent,我试图通过拖放在PyQt5创建的GUI上绘制一个矩形。我设法做到了这一点,但是当鼠标左键被释放时,矩形就被画出来了 我想做的是这样: 按下鼠标左键后,开始绘制矩形 拖动时,用鼠标移动调整矩形形状 释放鼠标左键后,确定矩形形状 我如何实现这一点?提前谢谢 这是我的密码 # -*- coding: utf-8 -*- import sys from PyQt5 import QtWidgets, QtCore from PyQt5.QtGui import QPainter class My
- 按下鼠标左键后,开始绘制矩形
- 拖动时,用鼠标移动调整矩形形状
- 释放鼠标左键后,确定矩形形状
# -*- coding: utf-8 -*-
import sys
from PyQt5 import QtWidgets, QtCore
from PyQt5.QtGui import QPainter
class MyWidget(QtWidgets.QWidget):
def __init__(self):
super().__init__()
self.setGeometry(30,30,600,400)
self.pos1 = [0,0]
self.pos2 = [0,0]
self.show()
def paintEvent(self, event):
width = self.pos2[0]-self.pos1[0]
height = self.pos2[1] - self.pos1[1]
qp = QPainter()
qp.begin(self)
qp.drawRect(self.pos1[0], self.pos1[1], width, height)
qp.end()
def mousePressEvent(self, event):
self.pos1[0], self.pos1[1] = event.pos().x(), event.pos().y()
print("clicked")
def mouseReleaseEvent(self, event):
self.pos2[0], self.pos2[1] = event.pos().x(), event.pos().y()
print("released")
self.update()
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
window = MyWidget()
window.show()
app.aboutToQuit.connect(app.deleteLater)
sys.exit(app.exec_())
您不必使用
mouseReleaseEvent
函数,而是每次移动鼠标时调用的mouseMoveEvent
函数,我已经修改了代码使其更简单
class MyWidget(QtWidgets.QWidget):
def __init__(self):
super().__init__()
self.setGeometry(30,30,600,400)
self.begin = QtCore.QPoint()
self.end = QtCore.QPoint()
self.show()
def paintEvent(self, event):
qp = QtGui.QPainter(self)
br = QtGui.QBrush(QtGui.QColor(100, 10, 10, 40))
qp.setBrush(br)
qp.drawRect(QtCore.QRect(self.begin, self.end))
def mousePressEvent(self, event):
self.begin = event.pos()
self.end = event.pos()
self.update()
def mouseMoveEvent(self, event):
self.end = event.pos()
self.update()
def mouseReleaseEvent(self, event):
self.begin = event.pos()
self.end = event.pos()
self.update()
谢谢你的回答和修改我的代码。这正是我一直在寻找的。如果我画另一个矩形,前一个矩形就会消失。为什么?