关于python：用pyqt5逐步绘制的正确方法

Correct way to paint progressively with pyqt5

我有一个基本上是圆形的小部件。我想逐步绘制它，所以我需要逐步绘制它(imo)。

通过以下代码，我已经实现了我想要的。但是，有一个问题。我正在将一个新事件传递给 paintEvent 函数，因为如果我不这样做，图像不会在一切都完成之前得到更新，所以我没有得到任何我想要的结果。

小部件代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66

import sys
import time
from PyQt5.QtCore import Qt, QRect
from PyQt5.QtWidgets import QApplication, QWidget, QCheckBox, QDesktopWidget

from PyQt5.QtGui import QPen, QPainter, QPaintEvent, QConicalGradient, QColor, QBrush

class Circle(QWidget):

def __init__(self, size, color):
super().__init__()

self.loadingAngle = 0
self.width = 0
self.color = color
self.pixmap_opacity = 1

self.resize(size, size);
self.center()

self.initUI()

def initUI(self):

self.width = 15
self.loadingAngle = 0
self.show()

def center(self):
qr = self.frameGeometry()
cp = QDesktopWidget().availableGeometry().center()
qr.moveCenter(cp)
self.move(qr.topLeft())

def paintEvent(self, qevent):

self.setWindowFlags(Qt.FramelessWindowHint)
self.setAttribute(Qt.WA_TranslucentBackground)
self.setStyleSheet("background:transparent;")

drawingRect = QRect()
drawingRect.setX(qevent.rect().x() + self.width)
drawingRect.setY(qevent.rect().y() + self.width)
drawingRect.setWidth(qevent.rect().width() – self.width * 2)
drawingRect.setHeight(qevent.rect().height() – self.width * 2)

painter = QPainter(self)
painter.setRenderHint(QPainter.Antialiasing)

gradient = QConicalGradient()
gradient.setCenter(drawingRect.center())
gradient.setAngle(90)
gradient.setColorAt(1, QColor(0,0,0))
gradient.setColorAt(0, QColor(self.color[0], self.color[1],self.color[2]))

arcLengthApproximation = self.width + self.width / 3
pen = QPen(QBrush(gradient), self.width)
pen.setCapStyle(Qt.RoundCap)
painter.setPen(pen)
painter.drawArc(drawingRect, 90 * 16 – arcLengthApproximation, –self.loadingAngle * 16)
#time.sleep(0.25)

if self.loadingAngle < 360:
self.loadingAngle += 1
#self.paintEvent(QDrawEvent())
self.paintEvent(QPaintEvent())

有问题的线路

1	self.paintEvent(QPaintEvent())

这条线产生了几个错误，但即使有它们，我也会做我想做的。

如果我将 qevent 从函数本身传递给这个新调用，图像不会像我之前所说的那样得到更新。

如果我创建这个新的 QPaintEvent，它确实有效。但是，错误是：

Traceback (most recent call last):

File”/home/btc/Escritorio/SinestesiaRCB/Clases/Widget.py”, line 68, in
paintEvent self.paintEvent(QPaintEvent())

TypeError: arguments did not match any overloaded call:
QPaintEvent(QRegion): not enough arguments

QPaintEvent(QRect): not enough arguments

QPaintEvent(QPaintEvent): not enough arguments

QBackingStore::endPaint() called with active painter on backingstore paint device

这些错误可能来自其他行，例如：

1	qevent.rect().x()

因为新事件是空的。

所以基本上我的问题是，我应该怎么做才能正确地做到这一点，这意味着没有错误地实现我想要的？

PS。我所说的渐进式。这已经创建了几个小部件，每个小部件都在前一秒之后。

enter

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66

import sys
from PyQt5 import QtCore, QtGui, QtWidgets

class Circle(QtWidgets.QWidget):
def __init__(self, size, color):
super().__init__()
self._loading_angle = 0
self.width = 0
self.color = color
self.pixmap_opacity = 1
self.resize(size, size)
self.setWindowFlags(QtCore.Qt.FramelessWindowHint)
self.setAttribute(QtCore.Qt.WA_TranslucentBackground)
self.setStyleSheet("background:transparent;")
self.center()
self.initUI()

timeline = QtCore.QTimeLine(4000, self)
timeline.setFrameRange(0, 360)
timeline.frameChanged.connect(self.setLoadingAngle)
timeline.start()

def initUI(self):
self.width = 15
self.setLoadingAngle(0)
self.show()

def loadingAngle(self):
return self._loading_angle

def setLoadingAngle(self, angle):
self._loading_angle = angle
self.update()

loadingAngle = QtCore.pyqtProperty(int, fget=loadingAngle, fset=setLoadingAngle)

def center(self):
qr = self.frameGeometry()
cp = QtWidgets.QDesktopWidget().availableGeometry().center()
qr.moveCenter(cp)
self.move(qr.topLeft())

def paintEvent(self, event):
painter = QtGui.QPainter(self)
painter.setRenderHint(QtGui.QPainter.Antialiasing)
drawingRect = QtCore.QRect(QtCore.QPoint(), self.rect().size() – 2*self.width*QtCore.QSize(1, 1))
drawingRect.moveCenter(self.rect().center())

gradient = QtGui.QConicalGradient()
gradient.setCenter(drawingRect.center())
gradient.setAngle(90)
gradient.setColorAt(1, QtGui.QColor(0,0,0))
gradient.setColorAt(0, self.color)
arcLengthApproximation = self.width + self.width / 3
pen = QtGui.QPen(QtGui.QBrush(gradient), self.width)
pen.setCapStyle(QtCore.Qt.RoundCap)
painter.setPen(pen)
painter.drawArc(drawingRect, 90 * 16 – arcLengthApproximation, –self._loading_angle * 16)

if __name__ == ‘__main__’:
import sys
app = QtWidgets.QApplication(sys.argv)
w = Circle(400, QtGui.QColor("blue"))
w.show()
sys.exit(app.exec_())

原创文章，作者：ItWorker，如若转载，请注明出处：https://blog.ytso.com/268011.html

关于python：用pyqt5逐步绘制的正确方法

Correct way to paint progressively with pyqt5

相关推荐

发表回复