如何在PyQt5中通过拖放绘制矩形并调整形状
How to draw a rectangle and adjust its shape by drag and drop in PyQt5
我正在尝试通过拖放在 PyQt5 创建的 GUI 上绘制一个矩形。我设法做到了,但是当鼠标左键被释放时矩形被绘制出来了。
我想做的是这样的link:
- 当按下鼠标左键时,开始绘制矩形。
- 拖动时,用鼠标移动调整矩形形状。
- 当鼠标左键松开时,确定矩形。
我该如何实现?提前致谢。
这是我的代码。
# -*- 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_())
不一定要用mouseReleaseEvent
函数,而是每次移动鼠标都会调用的mouseMoveEvent
函数,我修改了代码,让它更简单。
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()
我正在尝试通过拖放在 PyQt5 创建的 GUI 上绘制一个矩形。我设法做到了,但是当鼠标左键被释放时矩形被绘制出来了。
我想做的是这样的link:
- 当按下鼠标左键时,开始绘制矩形。
- 拖动时,用鼠标移动调整矩形形状。
- 当鼠标左键松开时,确定矩形。
我该如何实现?提前致谢。
这是我的代码。
# -*- 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_())
不一定要用mouseReleaseEvent
函数,而是每次移动鼠标都会调用的mouseMoveEvent
函数,我修改了代码,让它更简单。
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()