PyQt5实现画布小程序
xiaopengyaonixi 人气:2本文实例为大家分享了PyQt5实现画布小程序的具体代码,供大家参考,具体内容如下
实现的效果图如下:
该实例中,涉及到的知识点有:
1.PyQt5 的常用的布局方式,这里使用到了QVBoxLayout,QHBoxLayout,如何灵活运用这些布局;
2.常用组件的使用方法,这里使用到了QPushButton, QLabel, QPixmap;
3.使用QPainter进行绘制;
4.事件与槽;
主要代码如下:
import random import sys from PyQt5.QtCore import QSize from PyQt5.QtGui import QPixmap, QPainter, QColor from PyQt5.QtWidgets import QMainWindow, QLabel, QApplication, QPushButton, QWidget, QVBoxLayout, QHBoxLayout SPRAY_PARTICLES = 100 SPRAY_DIAMMETER = 10 COLORS = [ '#000000', '#141923', '#414168', '#3a7fa7', '#35e3e3', '#8fd970', '#5ebb49', '#458352', '#dcd37b', '#fffee5', '#ffd035', '#cc9245', '#a15c3e', '#a42f3b', '#f45b7a', '#c24998', '#81588d', '#bcb0c2', '#ffffff', ] class QPlatteButton(QPushButton): def __init__(self, color): super().__init__() self.setFixedSize(QSize(24, 24)) self.color = color self.setStyleSheet("background-color: %s" % self.color) class Canvas(QLabel): def __init__(self): super().__init__() canvas = QPixmap(1200, 800) canvas.fill(QColor('white')) self.setPixmap(canvas) self.last_x, self.last_y = None, None self.pen_color = QColor('#000') def set_pen_color(self, c): self.pen_color = QColor(c) def mouseReleaseEvent(self, *args, **kwargs): """ 松开鼠标事件 """ self.last_x, self.last_y = None, None def mouseMoveEvent(self, e): """ 移动鼠标事件 """ if self.last_x is None: self.last_x = e.x() self.last_y = e.y() return painter = QPainter(self.pixmap()) pen = painter.pen() pen.setWidth(4) pen.setColor(self.pen_color) painter.setPen(pen) painter.drawLine(self.last_x, self.last_y, e.x(), e.y()) painter.end() self.update() # update the origin for next time self.last_x = e.x() self.last_y = e.y() # def mouseMoveEvent(self, e): # painter = QPainter(self.pixmap()) # p = painter.pen() # p.setWidth(1) # p.setColor(self.pen_color) # painter.setPen(p) # # for n in range(SPRAY_PARTICLES): # xo = random.gauss(0, SPRAY_DIAMMETER) # yo = random.gauss(0, SPRAY_DIAMMETER) # painter.drawPoint(e.x() + xo, e.y() + yo) # # self.update() class MainWindow(QMainWindow): def __init__(self): super().__init__() self.setWindowTitle("画板小程序") self.canvas = Canvas() widget = QWidget() vlayout = QVBoxLayout() widget.setLayout(vlayout) vlayout.addWidget(self.canvas) palette = QHBoxLayout() vlayout.addLayout(palette) self.add_palette_buttons(palette) self.setCentralWidget(widget) def add_palette_buttons(self, layout): """ 在水平布局中放入一行调色板 """ for c in COLORS: b = QPlatteButton(c) b.pressed.connect(lambda c=c: self.canvas.set_pen_color(c)) layout.addWidget(b) if __name__ == '__main__': app = QApplication(sys.argv) window = MainWindow() window.move(120, 120) window.show() app.exec_()
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