Python/pyqt5/CODE/元件使用範例/qt04_drawPoint.py

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# -*- coding: utf-8 -*-
"""
簡介
在視窗中畫點的範例
"""
import sys, math
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import Qt
class Drawing(QWidget):
def __init__(self, parent=None):
super(Drawing, self).__init__(parent)
self.resize(300, 200)
self.setWindowTitle("在視窗中畫點")
def paintEvent(self, event):
# 初始化繪圖工具
qp = QPainter()
qp.begin(self)
# 自訂畫點方法
self.drawPoints(qp)
qp.end()
def drawPoints(self, qp):
qp.setPen( Qt.red)
size = self.size()
for i in range(1000):
# 繪製正弦函數圖形,它的週期是[-100, 100]
x = 100 *(-1+2.0*i/1000)+ size.width()/2.0
y = -50 * math.sin((x - size.width()/2.0)*math.pi/50) + size.height()/2.0
qp.drawPoint(x, y)
if __name__ == '__main__':
app = QApplication(sys.argv)
demo = Drawing()
demo.show()
sys.exit(app.exec_())