python pyqt5 绘图QPixmap
image.png
-- coding: utf-8 --
""" 【简介】 使用paintEvent在窗口实现划线例子
"""
import sys from PyQt5.QtWidgets import QApplication, QWidget from PyQt5.QtGui import QPainter, QPixmap from PyQt5.QtCore import Qt, QPoint
class Winform(QWidget): def init(self, parent=None): super(Winform, self).init(parent) self.setWindowTitle("绘图例子") self.pix = QPixmap() self.lastPoint = QPoint() self.endPoint = QPoint() self.initUi()
def initUi(self):
# 窗口大小设置为600*500
self.resize(600, 500)
# 画布大小为400*400，背景为白色
self.pix = QPixmap(400, 400)
self.pix.fill(Qt.white)
def paintEvent(self, event):
pp = QPainter(self.pix)
# 根据鼠标指针前后两个位置绘制直线
pp.drawLine(self.lastPoint, self.endPoint)
# 让前一个坐标值等于后一个坐标值，
# 这样就能实现画出连续的线
self.lastPoint = self.endPoint
painter = QPainter(self)
painter.drawPixmap(0, 0, self.pix)
def mousePressEvent(self, event):
# 鼠标左键按下
if event.button() == Qt.LeftButton:
self.lastPoint = event.pos()
self.endPoint = self.lastPoint
def mouseMoveEvent(self, event):
# 鼠标左键按下的同时移动鼠标
if event.buttons() and Qt.LeftButton:
self.endPoint = event.pos()
# 进行重新绘制
self.update()
def mouseReleaseEvent(self, event):
# 鼠标左键释放
if event.button() == Qt.LeftButton:
self.endPoint = event.pos()
# 进行重新绘制
self.update()if name == "main": app = QApplication(sys.argv) form = Winform() form.show() sys.exit(app.exec_())
-- coding: utf-8 --
""" 【简介】 双缓冲绘图
"""
import sys from PyQt5.QtWidgets import QApplication, QWidget from PyQt5.QtGui import QPainter, QPixmap from PyQt5.QtCore import Qt, QPoint
class Winform(QWidget): def init(self, parent=None): super(Winform, self).init(parent) self.setWindowTitle("双缓冲绘图例子") self.pix = QPixmap() self.lastPoint = QPoint() self.endPoint = QPoint() # 辅助画布 self.tempPix = QPixmap() # 标志是否正在绘图 self.isDrawing = False self.initUi()
def initUi(self):
# 窗口大小设置为600*500
self.resize(600, 500);
# 画布大小为400*400，背景为白色
self.pix = QPixmap(400, 400);
self.pix.fill(Qt.white);
def paintEvent(self, event):
painter = QPainter(self)
x = self.lastPoint.x()
y = self.lastPoint.y()
w = self.endPoint.x() - x
h = self.endPoint.y() - y
# 如果正在绘图，就在辅助画布上绘制
if self.isDrawing:
# 将以前pix中的内容复制到tempPix中，保证以前的内容不消失
self.tempPix = self.pix
pp = QPainter(self.tempPix)
pp.drawRect(x, y, w, h)
painter.drawPixmap(0, 0, self.tempPix)
else:
pp = QPainter(self.pix)
pp.drawRect(x, y, w, h)
painter.drawPixmap(0, 0, self.pix)
def mousePressEvent(self, event):
# 鼠标左键按下
if event.button() == Qt.LeftButton:
self.lastPoint = event.pos()
self.endPoint = self.lastPoint
self.isDrawing = True
def mouseReleaseEvent(self, event):
# 鼠标左键释放
if event.button() == Qt.LeftButton:
self.endPoint = event.pos()
# 进行重新绘制
self.update()
self.isDrawing = Falseif name == "main": app = QApplication(sys.argv) form = Winform() form.show() sys.exit(app.exec_())