如何使用 PySide2 在 matplotlib 中显示图形？

Question

我正在尝试学习 matplotlib 并尝试测试以下代码。

import matplotlib
from matplotlib.figure import Figure  
import matplotlib
from matplotlib.figure import Figure
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as     FigureCanvas
import sys
from PySide2 import QtGui   

if __name__ == "__main__":

    app = QtGui.QApplication(sys.argv)
    wid = QtGui.QWidget()
    wid.resize(250, 150)
    grid = QtGui.QGridLayout()
    wid.setLayout(grid)
    fig = Figure(figsize=(7,5), dpi=65, facecolor=(1,1,1), edgecolor=(0,0,0))
    canvas = FigureCanvas(fig)
    grid.addWidget(canvas)
    wid.show()

然而它似乎无法识别图的签名。

TypeError：使用错误的参数类型调用“PySide2.QtGui.QGridLayout.addWidget”：
PySide2.QtGui.QGridLayout.addWidget(FigureCanvasQTAgg) 支持的签名：
PySide2.QtGui.QGridLayout.addWidget(PySide2.QtGui.QWidget, int, int, PySide2. QtCore.Qt.Alignment = 0)
PySide2.QtGui.QGridLayout.addWidget(PySide2.QtGui.QWidget, int, int, int, int, PySide2.QtCore.Qt.Alignment = 0)

Answer 1

PySide2 是 Qt5 的绑定，因此您必须使用backend_qt5agg而不是backend_qt4agg，另一方面建议在 matplotlib 之前导入后端（本例中为 PySide2），以便 matplotlib 在内部配置它，除了 QApplication、QWidget 和 QGridLayout 属于 QtWidgets由于 Qt5 将它们与 QtGui 分开，最后当您将小部件添加到 QGridLayout 时，您必须在以下参数中指示其位置。

考虑到上述情况，解决方案是

import sys

from PySide2 import QtWidgets
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure


if __name__ == "__main__":

    app = QtWidgets.QApplication(sys.argv)
    wid = QtWidgets.QWidget()
    wid.resize(250, 150)
    grid = QtWidgets.QGridLayout(wid)
    fig = Figure(figsize=(7, 5), dpi=65, facecolor=(1, 1, 1), edgecolor=(0, 0, 0))
    canvas = FigureCanvas(fig)
    grid.addWidget(canvas, 0, 0)
    wid.show()
    sys.exit(app.exec_())