import sys
from PyQt5.QtGui import *
from PyQt5.QtCore import *
from PyQt5 import uic, QtWidgets
qtCreatorFile = "d:/backup/python/程序/PyQt/2D_draw/2D_draw_scrawl.ui"
Ui_MainWindow, QtBaseClass = uic.loadUiType(qtCreatorFile)
class MyDraw(QtWidgets.QWidget, Ui_MainWindow):
def __init__(self):
QtWidgets.QWidget.__init__(self)
Ui_MainWindow.__init__(self)
self.setupUi(self)
self.pix = QPixmap(300, 300)
self.pix.fill(QColor(255, 255, 255))
self.endPoint = QPoint()
self.lastPoint = QPoint()
self.painter = QPainter()
def paintEvent(self, event):
self.painter.begin(self)
self.painter.drawPixmap(0, 0, self.pix)
self.painter.end()
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
self.lastPoint = event.pos()
self.endPoint = self.lastPoint
def mouseMoveEvent(self, event):
if event.buttons() == Qt.LeftButton: # 这里只能用buttons(), 因为button()在mouseMoveEvent()中无论
self.endPoint = event.pos() # 按下什么键，返回的都是Qt::NoButton
self.painter.begin(self.pix) # 注意这里的参数必须是self.pix，涂鸦只能在这个300*300的白板上进行
self.painter.setPen(QColor(0, 255, 0))
self.painter.drawLine(self.lastPoint, self.endPoint)
self.painter.end()
self.update()
self.lastPoint = self.endPoint
def mouseReleaseEvent(self, event):
if event.button() == Qt.LeftButton:
self.endPoint = event.pos()
self.update()
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
window = MyDraw()
window.show()
sys.exit(app.exec_())
