如何在 pyqt 中嵌入 matplotlib

问题描述：

我想在 pyqt4 用户界面中嵌入一个图形。我不明白人们如何在我找到的示例中进行嵌入 -这个（在底部） 和那个。

有人可以发布一步一步的解释，或者至少发布一个非常小、非常简单的代码，例如在一个 pyqt4 GUI 中创建一个图形和一个按钮。

解决方案 1：

其实并没有那么复杂。相关的 Qt 小部件位于 中matplotlib.backends.backend_qt4agg。FigureCanvasQTAgg并且NavigationToolbar2QT通常是您所需要的。这些是常规的 Qt 小部件。您可以像对待任何其他小部件一样对待它们。下面是一个非常简单的示例Figure，其中包含一个Navigation和一个绘制一些随机数据的按钮。我添加了注释来解释事情。

import sys
from PyQt4 import QtGui

from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt4agg import NavigationToolbar2QT as NavigationToolbar
from matplotlib.figure import Figure

import random

class Window(QtGui.QDialog):
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)

        # a figure instance to plot on
        self.figure = Figure()

        # this is the Canvas Widget that displays the `figure`
        # it takes the `figure` instance as a parameter to __init__
        self.canvas = FigureCanvas(self.figure)

        # this is the Navigation widget
        # it takes the Canvas widget and a parent
        self.toolbar = NavigationToolbar(self.canvas, self)

        # Just some button connected to `plot` method
        self.button = QtGui.QPushButton('Plot')
        self.button.clicked.connect(self.plot)

        # set the layout
        layout = QtGui.QVBoxLayout()
        layout.addWidget(self.toolbar)
        layout.addWidget(self.canvas)
        layout.addWidget(self.button)
        self.setLayout(layout)

    def plot(self):
        ''' plot some random stuff '''
        # random data
        data = [random.random() for i in range(10)]

        # create an axis
        ax = self.figure.add_subplot(111)

        # discards the old graph
        ax.clear()

        # plot data
        ax.plot(data, '*-')

        # refresh canvas
        self.canvas.draw()

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)

    main = Window()
    main.show()

    sys.exit(app.exec_())

编辑：

已更新以反映评论和 API 变化。

• NavigationToolbar2QTAgg改为NavigationToolbar2QT

• 直接导入Figure而不是pyplot

• 替换已弃用ax.hold(False)的ax.clear()

解决方案 2：

以下是之前代码的改编，适用于PyQt5和Matplotlib 2.0。有许多小的变化：PyQt 子模块的结构、matplotlib 的其他子模块、弃用的方法已被替换……

import sys
from PyQt5.QtWidgets import QDialog, QApplication, QPushButton, QVBoxLayout

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

import random

class Window(QDialog):
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)

        # a figure instance to plot on
        self.figure = plt.figure()

        # this is the Canvas Widget that displays the `figure`
        # it takes the `figure` instance as a parameter to __init__
        self.canvas = FigureCanvas(self.figure)

        # this is the Navigation widget
        # it takes the Canvas widget and a parent
        self.toolbar = NavigationToolbar(self.canvas, self)

        # Just some button connected to `plot` method
        self.button = QPushButton('Plot')
        self.button.clicked.connect(self.plot)

        # set the layout
        layout = QVBoxLayout()
        layout.addWidget(self.toolbar)
        layout.addWidget(self.canvas)
        layout.addWidget(self.button)
        self.setLayout(layout)

    def plot(self):
        ''' plot some random stuff '''
        # random data
        data = [random.random() for i in range(10)]

        # instead of ax.hold(False)
        self.figure.clear()

        # create an axis
        ax = self.figure.add_subplot(111)

        # discards the old graph
        # ax.hold(False) # deprecated, see above

        # plot data
        ax.plot(data, '*-')

        # refresh canvas
        self.canvas.draw()

if __name__ == '__main__':
    app = QApplication(sys.argv)

    main = Window()
    main.show()

    sys.exit(app.exec_())

解决方案 3：

对于那些寻找动态解决方案以将 Matplotlib 嵌入 PyQt5（甚至使用拖放绘制数据）的人来说。在 PyQt5 中，您需要在主窗口类上使用 super 来接受拖放。dropevent 函数可用于获取文件名，其余的很简单：

def dropEvent(self,e):
        """
        This function will enable the drop file directly on to the 
        main window. The file location will be stored in the self.filename
        """
        if e.mimeData().hasUrls:
            e.setDropAction(QtCore.Qt.CopyAction)
            e.accept()
            for url in e.mimeData().urls():
                if op_sys == 'Darwin':
                    fname = str(NSURL.URLWithString_(str(url.toString())).filePathURL().path())
                else:
                    fname = str(url.toLocalFile())
            self.filename = fname
            print("GOT ADDRESS:",self.filename)
            self.readData()
        else:
            e.ignore() # just like above functions  

对于初学者来说，参考完整代码给出以下输出：