我正在尝试创建一个显示大数字网格的程序（例如，填充6乘4000网格），用户可以通过键盘或鼠标移动光标并在网格中输入数字。 （这是一个吉他指法程序。）我是python GUI编程的新手，到目前为止，我的想法是在主窗口内的QScrollArea内部有一个非常大的QWidget窗口（例如，1000x80000像素）。问题是，每次鼠标点击或光标移动都会导致整个事情重新绘制，导致延迟，当我只想重新绘制我刚才所做的任何更改以使事情变得更快时。在PyQt中，有没有办法缓冲已绘制的图形并只更改需要更改的图形？
编辑：我发布了下面的代码，我在Mac OS 10.7上使用python3.3运行。重点是在TabWindow init 函数中，网格大小可以通过numXGrid和numYGrid设置（当前设置为200和6），并且此网格由generateRandomTablatureData（）填充随机数方法。如果网格中充满了数字，那么每次按键都会出现明显的滞后现象，大网格会变得更糟。 （由于生成数据也存在初始延迟，但我的问题是每次按键后的延迟，我认为是由于必须重新绘制每个数字。）
有两个文件。这是主要的，我称之为FAIT.py：
import time
start_time = time.time()
import random
import sys
from PyQt4 import QtGui, QtCore
import Tracks
# generate tracks
tracks = [Tracks.Track(), Tracks.Track(), Tracks.Track()]
fontSize = 16
# margins
xMar = 50
yMar = 50
trackMar = 50 # margin between tracks
class MainWindow(QtGui.QWidget):
def __init__(self):
super(MainWindow, self).__init__()
self.initUI()
end_time = time.time()
print("Initializing time was %g seconds" % (end_time - start_time))
def initUI(self):
# attach QScrollArea to MainWindow
l = QtGui.QVBoxLayout(self)
l.setContentsMargins(0,0,0,0)
l.setSpacing(0)
s=QtGui.QScrollArea()
l.addWidget(s)
# attach TabWindow to QScrollArea so we can paint on it
self.tabWindow=TabWindow(self)
self.tabWindow.setFocusPolicy(QtCore.Qt.StrongFocus)
self.setFocusPolicy(QtCore.Qt.NoFocus)
vbox=QtGui.QVBoxLayout(self.tabWindow)
s.setWidget(self.tabWindow)
self.positionWindow() # set size and position of main window
self.setWindowTitle('MainWindow')
self.show()
def positionWindow(self):
qr = self.frameGeometry()
cp = QtGui.QDesktopWidget().availableGeometry().center()
width = QtGui.QDesktopWidget().availableGeometry().width() - 100
height = QtGui.QDesktopWidget().availableGeometry().height() - 100
self.resize(width, height)
qr = self.frameGeometry()
cp = QtGui.QDesktopWidget().availableGeometry().center()
qr.moveCenter(cp)
self.move(qr.topLeft())
def keyPressEvent(self, e):
print('key pressed in MainWindow')
def mousePressEvent(self, e):
print('mouse click in MainWindow')
class TabWindow(QtGui.QWidget):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
# size of tablature grid
numXGrid = 200
numYGrid = 6
# initialize tablature information first
for i in range(0, len(tracks)):
tracks[i].numXGrid = numXGrid
self.arrangeTracks() # figure out offsets for each track
self.trackFocusNum = 0 # to begin with, focus is on track 0
self.windowSizeX = tracks[0].x0 + tracks[0].dx*(tracks[0].numXGrid+2)
self.windowSizeY = tracks[0].y0
for i in range(0, len(tracks)):
self.windowSizeY = self.windowSizeY + tracks[i].dy * tracks[i].numYGrid + trackMar
self.resize(self.windowSizeX,self.windowSizeY) # size of actual tablature area
# generate random tablature data for testing
self.generateRandomTablatureData()
def keyPressEvent(self, e):
print('key pressed in TabWindow')
i = self.trackFocusNum
if e.key() == QtCore.Qt.Key_Up:
tracks[i].moveCursorUp()
if e.key() == QtCore.Qt.Key_Down:
tracks[i].moveCursorDown()
if e.key() == QtCore.Qt.Key_Left:
tracks[i].moveCursorLeft()
if e.key() == QtCore.Qt.Key_Right:
tracks[i].moveCursorRight()
# check for number input
numberKeys = (QtCore.Qt.Key_0,
QtCore.Qt.Key_1,
QtCore.Qt.Key_2,
QtCore.Qt.Key_3,
QtCore.Qt.Key_4,
QtCore.Qt.Key_5,
QtCore.Qt.Key_6,
QtCore.Qt.Key_7,
QtCore.Qt.Key_8,
QtCore.Qt.Key_9)
if e.key() in numberKeys:
num = int(e.key())-48
# add data
tracks[i].data.addToTab(tracks[i].iCursor, tracks[i].jCursor, num)
# convert entered number to pitch and play note (do later)
# spacebar, backspace, or delete remove data
if e.key() in (QtCore.Qt.Key_Space, QtCore.Qt.Key_Backspace, QtCore.Qt.Key_Delete):
tracks[i].data.removeFromTab(tracks[i].iCursor, tracks[i].jCursor)
self.update()
def mousePressEvent(self, e):
print('mouse click in TabWindow')
xPos = e.x()
yPos = e.y()
# check tracks one by one
for i in range(0, len(tracks)):
if (tracks[i].isPositionInside(xPos, yPos)):
tracks[i].moveCursorToPosition(xPos, yPos)
self.trackFocusNum = i
break
else:
continue
self.update()
def paintEvent(self, e):
qp = QtGui.QPainter()
qp.begin(self)
qp.setPen(QtCore.Qt.black)
qp.setBrush(QtCore.Qt.white)
qp.drawRect(0, 0, self.windowSizeX, self.windowSizeY)
self.paintTracks(qp)
self.paintTunings(qp)
self.paintCursor(qp)
self.paintNumbers(qp)
qp.end()
def paintTracks(self, qp):
qp.setPen(QtCore.Qt.black)
qp.setBrush(QtCore.Qt.white)
for i in range(0, len(tracks)):
qp.drawPolyline(tracks[i].polyline)
def paintCursor(self, qp):
i = self.trackFocusNum
qp.setPen(QtCore.Qt.black)
qp.setBrush(QtCore.Qt.black)
qp.drawPolygon(tracks[i].getCursorQPolygon())
def paintNumbers(self, qp):
# iterate through tracks, and iterate through numbers on each track
for i in range(0, len(tracks)):
# make sure track has data to draw
if len(tracks[i].data.data) > 0:
for j in range(0, len(tracks[i].data.data)):
# do actual painting here
# first set color to be inverse cursor color if at cursor
if i == self.trackFocusNum and \
tracks[i].iCursor == tracks[i].data.data[j][0] and \
tracks[i].jCursor == tracks[i].data.data[j][1]:
qp.setPen(QtCore.Qt.white)
else:
qp.setPen(QtCore.Qt.black)
font = QtGui.QFont('Helvetica', fontSize)
qp.setFont(font)
text = str(tracks[i].data.data[j][2])
x1 = tracks[i].convertIndexToPositionX(tracks[i].data.data[j][0])
y1 = tracks[i].convertIndexToPositionY(tracks[i].data.data[j][1])
dx = tracks[i].dx
dy = tracks[i].dy
# height and width of number character(s)
metrics = QtGui.QFontMetrics(font)
tx = metrics.width(text)
ty = metrics.height()
# formula for alignment:
# xMar = (dx-tx)/2 plus offset
x11 = x1 + (dx-tx)/2
y11 = y1 + dy/2+ty/2
qp.drawText(x11, y11, text)
def paintTunings(self, qp):
qp.setPen(QtCore.Qt.black)
font = QtGui.QFont('Helvetica', fontSize)
qp.setFont(font)
for i in range(0, len(tracks)):
for j in range(0, tracks[i].numStrings):
text = tracks[i].convertPitchToLetter(tracks[i].stringTuning[j])
# height and width of characters
metrics = QtGui.QFontMetrics(font)
tx = metrics.width(text)
ty = metrics.height()
x11 = tracks[i].x0 - tx - 10
y11 = tracks[i].convertIndexToPositionY(j) + (tracks[i].dy+ty)/2
qp.drawText(x11, y11, text)
def arrangeTracks(self):
tracks[0].x0 = xMar
tracks[0].y0 = yMar
tracks[0].generateGridQPolyline()
for i in range(1, len(tracks)):
tracks[i].x0 = xMar
tracks[i].y0 = tracks[i-1].y0 + tracks[i-1].height + trackMar
tracks[i].generateGridQPolyline()
def generateRandomTablatureData(self):
t1 = time.time()
for i in range(0, len(tracks)):
# worst case scenario: fill every number
for jx in range(0, tracks[i].numXGrid):
for jy in range(0, tracks[i].numYGrid):
val = random.randint(0,9)
tracks[i].data.addToTab(jx, jy, val)
t2 = time.time()
print("Random number generating time was %g seconds" % (t2 - t1))
def main():
app = QtGui.QApplication(sys.argv)
ex = MainWindow()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
这是另一个文件Tracks.py，它包含Track类和补充方法：
# contains classes and methods relating to individual tracks
import math
from PyQt4 import QtGui, QtCore
# class for containing information about a track
class Track:
def __init__(self):
self.data = TabulatureData()
# position offset
self.x0 = 0
self.y0 = 0
self.dx = 20 # default rectangle width
self.dy = 40 # default rectangle height
# current cursor index coordinates
self.iCursor = 0
self.jCursor = 0
# default size of grid
self.numXGrid = 4000
self.numYGrid = 6
self.numStrings = self.numYGrid
# calculated maximum width and height in pixels
self.maxWidth = self.dx * self.numXGrid
self.maxHeight = self.dy * self.numYGrid
# generate points of grid and cursor
self.generateGridQPolyline()
# tuning
self.setTuning([40, 45, 50, 55, 59, 64])
# calculate bounds
self.height = self.numYGrid*self.dy
self.width = self.numXGrid*self.dx
def getCursorIndexX(self, xPos):
iPos = int(math.floor( (xPos-self.x0)/self.dx ))
return iPos
def getCursorIndexY(self, yPos):
jPos = int(math.floor( (yPos-self.y0)/self.dy ))
return jPos
def convertIndexToCoordinates(self, iPos, jPos):
return [self.ConvertIndexToPositionX(iPos),
self.ConvertIndexToPositionY(jPos)]
def convertIndexToPositionX(self, iPos):
return self.x0 + iPos*self.dx
def convertIndexToPositionY(self, jPos):
return self.y0 + jPos*self.dy
def getCursorQPolygon(self):
x1 = self.convertIndexToPositionX(self.iCursor)
y1 = self.convertIndexToPositionY(self.jCursor)
x2 = self.convertIndexToPositionX(self.iCursor+1)
y2 = self.convertIndexToPositionY(self.jCursor+1)
return QtGui.QPolygonF([QtCore.QPoint(x1, y1),
QtCore.QPoint(x1, y2),
QtCore.QPoint(x2, y2),
QtCore.QPoint(x2, y1)])
def generateGridQPolyline(self):
self.points = []
self.polyline = QtGui.QPolygonF()
for i in range(0, self.numXGrid):
for j in range(0, self.numYGrid):
x1 = self.convertIndexToPositionX(i)
y1 = self.convertIndexToPositionY(j)
x2 = self.convertIndexToPositionX(i+1)
y2 = self.convertIndexToPositionY(j+1)
self.points.append([(x1, y1), (x1, y2), (x2, y2), (x2, y1)])
self.polyline << QtCore.QPoint(x1,y1) << \
QtCore.QPoint(x1,y2) << \
QtCore.QPoint(x2,y2) << \
QtCore.QPoint(x2,y1) << \
QtCore.QPoint(x1,y1)
# smoothly connect different rows
jLast = self.numYGrid-1
x1 = self.convertIndexToPositionX(i)
y1 = self.convertIndexToPositionY(jLast)
x2 = self.convertIndexToPositionX(i+1)
y2 = self.convertIndexToPositionY(jLast+1)
self.polyline << QtCore.QPoint(x2,y1)
def isPositionInside(self, xPos, yPos):
if (xPos >= self.x0 and xPos <= self.x0 + self.width and
yPos >= self.y0 and yPos <= self.y0 + self.height):
return True
else:
return False
def moveCursorToPosition(self, xPos, yPos):
self.iCursor = self.getCursorIndexX(xPos)
self.jCursor = self.getCursorIndexY(yPos)
self.moveCursorToIndex(self.iCursor, self.jCursor)
def moveCursorToIndex(self, iPos, jPos):
# check if bounds are breached, and if cursor's already there,
# and if not, move cursor
if iPos == self.iCursor and jPos == self.jCursor:
return
if iPos >= 0 and iPos < self.numXGrid:
if jPos >= 0 and jPos < self.numYGrid:
self.iCursor = iPos
self.jCursor = jPos
return
def moveCursorUp(self):
self.moveCursorToIndex(self.iCursor, self.jCursor-1)
def moveCursorDown(self):
self.moveCursorToIndex(self.iCursor, self.jCursor+1)
def moveCursorLeft(self):
self.moveCursorToIndex(self.iCursor-1, self.jCursor)
def moveCursorRight(self):
self.moveCursorToIndex(self.iCursor+1, self.jCursor)
# return pitch in midi integer notation
def convertNumberToPitch(self, jPos, pitchNum):
return pitchNum + self.stringTuning[(self.numStrings-1) - jPos]
def convertPitchToLetter(self, pitchNum):
p = pitchNum % 12
letters = ('C', 'Db', 'D', 'Eb', 'E', 'F', 'Gb', 'G', 'Ab', 'A', 'Bb', 'B')
return letters[p]
def setTuning(self, tuning):
self.stringTuning = tuning
class TabulatureData:
def __init__(self):
self.data = []
def addToTab(self, i, j, value):
# check if data is already there, and remove it first
if self.getValue(i, j) > -1:
self.removeFromTab(i, j)
self.data.append([i, j, value])
def getValue(self, i, j):
possibleTuples = [x for x in self.data if x[0] == i and x[1] == j]
if possibleTuples == []:
return -1
elif len(possibleTuples) > 1:
print('Warning: more than one number at a location!')
return possibleTuples[0][2] # return third number of tuple
def removeFromTab(self, i, j):
# first get value, if it exists
value = self.getValue(i,j)
if value == -1:
return
else:
# if it exists, then remove
self.data.remove([i, j, value])
答案 0 :(得分：1)
1000 * 80000真的很大。 那么，也许你应该尝试QGLWidget或类似的东西？ 或者根据Qt文档，您应该设置要重新绘制的区域。
一些缓慢的小部件需要通过仅绘制请求的区域进行优化：QPaintEvent :: region（）。此速度优化不会更改结果，因为在事件处理期间将绘制剪切到该区域。例如，QListView和QTableView就是这样做的。