我已经创建了一个小应用程序，并且正在尝试制作它，以便在调整主窗口的大小（并且GraphicsView和场景也是如此）时，整个场景（像素图和矩形）在垂直方向上可以缩放以完全容纳在内部GraphicsView。我不需要垂直滚动条，也不需要水平滚动条。
我不知道如何正确缩放场景。我使用GraphicsScene包含一个图形和几个垂直矩形“标记”。当我可以通过重画像素图然后重新附加来缩放图形以适合图时，则z顺序错误，矩形小部件也不会随之缩放。
我需要跟踪矩形窗口小部件，所以不能随便删除和重新添加它们，因为每个元数据都有元数据。
我知道适用于包含的GraphicsView的fitInView（从这里：Issue with fitInView of QGraphicsView when ItemIgnoresTransformations is on），但是我不明白为什么它需要一个参数。我只希望场景适合GraphicsView（垂直但不适合水平），那么为什么GraphicsView不能仅缩放场景中的所有内容以适合其当前大小？该参数应如何使场景垂直适合？
在resizeEvent中，我可以重绘像素图并重新添加，但是当z顺序混乱时，它会覆盖矩形。另外，它不会在场景中垂直居中，我需要复制元数据。
import sys
import os
from PyQt5 import QtCore, QtGui, QtWidgets
import PyQt5 as qt
from PyQt5.QtGui import QColor
from PyQt5.QtCore import Qt, QPoint
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QHBoxLayout, QGroupBox, QDialog, QVBoxLayout
from PyQt5.QtWidgets import QVBoxLayout, QGridLayout, QStackedWidget, QTabWidget
import numpy as np
class GraphicsScene(QtWidgets.QGraphicsScene):
def __init__(self, parent=None):
super(GraphicsScene, self).__init__(parent)
def minimumSizeHint(self):
return QtCore.QSize(300, 200)
def dragMoveEvent(self, event):
print("dragMoveEvent", event)
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
#super(MainWindow).__init__()
layout = QVBoxLayout()
layout.setContentsMargins(0, 0, 0, 0)
max_x, max_y = 2400, 700
max_x_view = 1200
self.max_x = max_x
self.max_y = max_y
self.first = True
self.setGeometry(200, 200, max_x_view, self.max_y)
self.gv = QtWidgets.QGraphicsView(self)
self.gv.setGeometry(0, 0, max_x_view, self.max_y)
self.gv2 = QtWidgets.QGraphicsView(self)
layout.addWidget(self.gv)
layout.addWidget(self.gv2)
scene = GraphicsScene()
self.scene = scene
self.gv.setScene(scene)
tab_widget = QTabWidget()
tab_widget.setTabPosition(QTabWidget.West)
widget = QWidget()
widget.setLayout(layout)
tab_widget.addTab(widget, "main")
self.setCentralWidget(tab_widget)
np.random.seed(777)
self.x_time = np.linspace(0, 12.56, 3000)
rand_data = np.random.uniform(0.0, 1.0, 3000)
self.data = .45*(np.sin(2*self.x_time) + rand_data) - .25*(np.sin(3*self.x_time))
self.first = True
pixmap_height = max_y//2 - 2*22 # 22 to take care of scrollbar height
pixmap = self.draw_graph()
pen = QtGui.QPen()
pen.setWidth(2)
pen.setColor(QtGui.QColor("red"))
self.gv1_pixmap = scene.addPixmap(pixmap)
rect = scene.sceneRect()
print("scene rect = {}".format(rect))
scene.setSceneRect(rect)
side, offset = 50, 200
for i in range(2):
r = QtCore.QRectF(QtCore.QPointF((i + 1)*offset + i * 2 * side, 2), QtCore.QSizeF(side, pixmap_height - 4))
rect_ref = scene.addRect(r, pen, QColor(255, 0, 0, 127))
rect_ref.setFlag(QtWidgets.QGraphicsItem.ItemIsMovable)
all_items = scene.items()
print(all_items)
def draw_graph(self):
print("draw_graph: main Window size {}:".format(self.size()))
pixmap_height = self.height()//2 - 2*22 # 22 to take care of scrollbar height
x_final = self.x_time[-1]
data = self.data / np.max(np.abs(self.data))
data = [abs(int(k * pixmap_height)) for k in self.data]
x_pos = [int(self.x_time[i] * self.max_x / x_final) for i in range(len(data))]
pixmap = QtGui.QPixmap(self.max_x, pixmap_height)
painter = QtGui.QPainter(pixmap)
pen = QtGui.QPen()
pen.setWidth(2)
rect = pixmap.rect()
pen.setColor(QtGui.QColor("red"))
painter.drawRect(rect)
print("pixmap rect = {}".format(rect))
painter.fillRect(rect, QtGui.QColor('lightblue'))
pen.setWidth(2)
pen.setColor(QtGui.QColor("green"))
painter.setPen(pen)
for x, y in zip(x_pos, data):
painter.drawLine(x, pixmap_height, x, pixmap_height - y)
painter.end()
return pixmap
def resizeEvent(self, a0: QtGui.QResizeEvent):
#print("main Window resizeEvent")
print("main Window size {}:".format(a0.size()))
redraw = False
if redraw:
pixmap = self.draw_graph()
self.scene.removeItem(self.gv1_pixmap)
self.gv1_pixmap = self.scene.addPixmap(pixmap)
self.gv1_pixmap.moveBy(0, 30)
else:
#rect = QtCore.QRect(self.gv.startPos, self.gv.endPos)
#sceneRect = self.gv.mapToScene(rect).boundingRect()
#print 'Selected area: viewport coordinate:', rect,', scene coordinate:', sceneRect
#self.gv.fitInView(sceneRect)
pass
app = QtWidgets.QApplication(sys.argv)
window = MainWindow()
window.show()
app.exec_()
答案 0 :(得分：2)
我的解决方案将适合将所有项目（sceneRect）封装到QGraphicsView视口的最小矩形的高度。因此，请将项目的高度设置为不太小的值，以免图像质量下降。我还使用QTransforms缩放了项目。另外，QGraphicsView坐标系是反转的，因为默认情况下垂直轴是上下坐标，而我已经将其反转了，以便绘画与数据更加一致。
我已经重构了OP代码以使其更具扩展性，其中有一个GraphItem可以接收数据（x，y）和图像尺寸。
考虑到上述情况，解决方案是：
import numpy as np
from PyQt5 import QtCore, QtGui, QtWidgets
class GraphItem(QtWidgets.QGraphicsPixmapItem):
def __init__(self, xdata, ydata, width, height, parent=None):
super(GraphItem, self).__init__(parent)
self._xdata = xdata
self._ydata = ydata
self._size = QtCore.QSize(width, height)
self.redraw()
def redraw(self):
x_final = self._xdata[-1]
pixmap = QtGui.QPixmap(self._size)
pixmap_height = pixmap.height()
pixmap.fill(QtGui.QColor("lightblue"))
painter = QtGui.QPainter(pixmap)
pen = QtGui.QPen(QtGui.QColor("green"))
pen.setWidth(2)
painter.setPen(pen)
for i, (x, y) in enumerate(
zip(self._xdata, self._ydata / np.max(np.abs(self._ydata)))
):
x_pos = int(x * self._size.width() / x_final)
y_pos = abs(int(y * pixmap_height))
painter.drawLine(x_pos, 0, x_pos, y_pos)
painter.end()
self.setPixmap(pixmap)
class HorizontalRectItem(QtWidgets.QGraphicsRectItem):
def itemChange(self, change, value):
if change == QtWidgets.QGraphicsItem.ItemPositionChange and self.scene():
newPos = self.pos()
newPos.setX(value.x())
return newPos
return super(HorizontalRectItem, self).itemChange(change, value)
class GraphicsView(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super(GraphicsView, self).__init__(parent)
scene = QtWidgets.QGraphicsScene(self)
self.setScene(scene)
self.scale(1, -1)
def resizeEvent(self, event):
h = self.mapToScene(self.viewport().rect()).boundingRect().height()
r = self.sceneRect()
r.setHeight(h)
self.setSceneRect(r)
height = self.viewport().height()
for item in self.items():
item_height = item.boundingRect().height()
tr = QtGui.QTransform()
tr.scale(1, height / item_height)
item.setTransform(tr)
super(GraphicsView, self).resizeEvent(event)
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
tab_widget = QtWidgets.QTabWidget(tabPosition=QtWidgets.QTabWidget.West)
self.setCentralWidget(tab_widget)
self.graphics_view_top = GraphicsView()
self.graphics_view_bottom = QtWidgets.QGraphicsView()
container = QtWidgets.QWidget()
lay = QtWidgets.QVBoxLayout(container)
lay.addWidget(self.graphics_view_top)
lay.addWidget(self.graphics_view_bottom)
tab_widget.addTab(container, "main")
self.resize(640, 480)
side, offset, height = 50, 200, 400
np.random.seed(777)
x_time = np.linspace(0, 12.56, 3000)
rand_data = np.random.uniform(0.0, 1.0, 3000)
data = 0.45 * (np.sin(2 * x_time) + rand_data) - 0.25 * (np.sin(3 * x_time))
graph_item = GraphItem(x_time, data, 3000, height)
self.graphics_view_top.scene().addItem(graph_item)
for i in range(2):
r = QtCore.QRectF(
QtCore.QPointF((i + 1) * offset + i * 2 * side, 2),
QtCore.QSizeF(side, height),
)
it = HorizontalRectItem(r)
it.setPen(QtGui.QPen(QtGui.QColor("red"), 2))
it.setBrush(QtGui.QColor(255, 0, 0, 127))
self.graphics_view_top.scene().addItem(it)
it.setFlags(
it.flags()
| QtWidgets.QGraphicsItem.ItemIsMovable
| QtWidgets.QGraphicsItem.ItemSendsGeometryChanges
)
def main():
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.show()
ret = app.exec_()
sys.exit(ret)
if __name__ == "__main__":
main()