如何在不缩小 QScrollArea 的情况下绘制图形？

Question

我正在创建一个界面，我想通过单击一个按钮在另一个选项卡中绘制图表。我希望图表在滚动区域中并排绘制。问题是，当我绘制图表时，图表实际上会缩小以适合小部件

，而不是滚动条在可视化上工作

这是一个最小的可重现示例

import sys
from PyQt5.QtWidgets import (QApplication, QMainWindow, QWidget, QPushButton,
                             QLabel, QVBoxLayout, QHBoxLayout, QMessageBox, 
                             QLineEdit,QComboBox, QAction, QTabWidget, QScrollArea)

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar

from matplotlib.figure import Figure
import matplotlib.pyplot as plt
                             
from PyQt5.QtCore import Qt
from PyQt5 import QtGui

class MainWindow(QMainWindow):    

    #view (GUI)
    def __init__(self, parent = None):
        #initalizer
        super(MainWindow, self).__init__(parent)
        
        #Window
        self.setWindowTitle("DataVisualizationPrototype")
        self.setGeometry(400, 200, 900, 800)
        self.activateWindow()
        self.raise_()
        
        
        self.tab_widget = TabWidget(self)
        self.setCentralWidget(self.tab_widget)
        
class TabWidget(QWidget):
    
    def __init__(self, parent):
        super(QWidget, self).__init__(parent)
        self.layout =QVBoxLayout(self)
        
        self.tabs = QTabWidget()
        self.tab1 = QWidget()
        self.tab2 = QWidget()
        self.tabs.addTab(self.tab1, "Home")
        self.tabs.addTab(self.tab2, "Comparison")
        self.layout.addWidget(self.tabs)
        self.setLayout(self.layout)
        
        
        #HOME PAGE
        #==========================================
        #GeneralLayout
        self.tab1layout = QVBoxLayout()
        self.tab1.setLayout(self.tab1layout)
        self.tab1layout.sizeHint()
        
        plotButton = QPushButton()
        self.tab1layout.addWidget(plotButton)
        plotbutton.clicked.connect(onclick2)

       
      
        #COMPARISON TAB
        #==========================================
        #GeneralLayout
        self.tab2layout = QVBoxLayout()
        self.tab2.setLayout(self.tab2layout)
        self.tab2layout.sizeHint()
        
        self.compGraphLayout = QHBoxLayout()
        self.compGraphLayout.addStretch()
        
        self.compScroll = QScrollArea()
        self.compScroll.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
        self.compScroll.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
        self.scrollWidget = QWidget()
        
        self.compScroll.setWidget(self.scrollWidget)
        self.compScroll.setWidgetResizable(True)
        
        self.tab2layout.addWidget(self.compScroll)
        self.scrollWidget.setLayout(self.compGraphLayout)
        
   def onclick2(self, event):
        self.plotLayout = QVBoxLayout()
        self.fig = plt.figure()
        self.plotLayout.addWidget(FigureCanvas(self.fig))
        
   
   
   
        self.plotLayout.addWidget(NavigationToolbar
                                 (FigureCanvas(self.fig),
                                  self.scrollWidget))
        self.compGraphLayout.addLayout(self.plotLayout)
        

#Plot MRE
        self.fig.plt.plot([1, 2, 3, 4])
        self.fig.plt.ylabel('some numbers')
        
        FigureCanvas(self.fig).adjustSize()
        
        
 
        
def main():

    pt1 = QApplication(sys.argv)
    view = MainWindow()
    view.show()
    
    sys.exit(pt1.exec())

if __name__ == '__main__':
    main()

Answer 1

OP 提供的代码混乱、冗余且有一些错别字，因此我将避免指出错误原因。

我的解决方案提出了一种简单明了的方法来实现水平显示绘图的目标。另一方面，canvas 没有合适的 sizeHint，因此小部件将被压缩，使滚动条不可见，因此一个可能的选择是设置最小宽度。

import sys

from PyQt5.QtWidgets import (
    QApplication,
    QMainWindow,
    QWidget,
    QPushButton,
    QVBoxLayout,
    QHBoxLayout,
    QTabWidget,
    QScrollArea,
)

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar

from matplotlib.figure import Figure


class MainWindow(QMainWindow):
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)

        # Window
        self.setWindowTitle("DataVisualizationPrototype")
        self.setGeometry(400, 200, 900, 800)
        self.activateWindow()
        self.raise_()

        self.tab_widget = TabWidget()
        self.setCentralWidget(self.tab_widget)


class TabWidget(QTabWidget):
    def __init__(self, parent=None):
        super(TabWidget, self).__init__(parent)

        self.tab1 = QWidget()
        self.plot_button = QPushButton("Add plot")
        lay = QVBoxLayout(self.tab1)
        lay.addWidget(self.plot_button)

        self.tab2 = QWidget()
        self.scroll_area = QScrollArea()
        self.scroll_container = QWidget()
        self.scroll_area.setWidgetResizable(True)
        self.scroll_area.setWidget(self.scroll_container)
        self.scroll_layout = QHBoxLayout(self.scroll_container)
        lay = QVBoxLayout(self.tab2)
        lay.addWidget(self.scroll_area)

        self.addTab(self.tab1, "Home")
        self.addTab(self.tab2, "Comparison")

        self.plot_button.clicked.connect(self.plot)

    def plot(self):
        canvas = FigureCanvas(Figure())
        ax = canvas.figure.add_subplot(111)
        toolbar = NavigationToolbar(canvas, self)

        container = QWidget()
        lay = QVBoxLayout(container)
        lay.addWidget(canvas)
        lay.addWidget(toolbar)

        self.scroll_layout.addWidget(container)
        container.setMinimumWidth(400)

        ax.plot([1, 2, 3, 4])
        ax.set_ylabel("some numbers")


def main():

    app = QApplication(sys.argv)
    view = MainWindow()
    view.show()

    sys.exit(app.exec())


if __name__ == "__main__":
    main()

如何在不缩小 QScrollArea 的情况下绘制图形？

How to plot graphs in QScrollArea without shrinking them?

python

matplotlib

user-interface

pyqt5

qscrollarea