我目前正在尝试使用PyQt5创建图形界面。到目前为止，一切都运转良好（毕竟我对此有一定的经验），但是我已经为这个问题苦苦挣扎了几天，而且我在任何地方都找不到解决方案。
[在我的应用程序中，我显示了来自matplotlib的FigureCanvas（以及其他各种小部件），其中有一个键事件连接到一个函数，该函数从鼠标单击中选取一个点并将该点保存在QTableWidget中。但是，我希望用户能够编辑使用验证器拾取的y值，因此我将第二列从保存QTableWidgetItem更改为QLineEdit小部件。一切正常，除非在编辑表中的QLineEdit小部件后按Enter键，焦点不会按预期变化（我将焦点设置为返回画布，但单元格保持活动状态，并且光标闪烁）。
在同一应用中，我在布局中的其他位置有另一个QLineEdit小部件，该小部件可以按预期工作。当我在此框中按Enter时，与其returnPressed信号相关的函数会将焦点发送回画布。
[谁能帮我弄清楚发生了什么吗？
[您知道如何解决此问题吗？我将我的应用程序剥离回下面粘贴的一个最小示例，其行为保持不变。
仅作总结：
为什么QLineEdit的两个实例表现不同？
作为参考，函数'print_val'的输出给我：TableWidget有焦点吗？假单元格编辑器有焦点吗？ False
提前感谢！
import sys
from matplotlib.backends.backend_qt5agg import FigureCanvas, NavigationToolbar2QT as NavigationToolbar
from matplotlib.figure import Figure
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
class GraphicInterface(QMainWindow):
def __init__(self, parent=None):
QMainWindow.__init__(self, parent)
self.setWindowTitle('Test')
self._main = QWidget()
self.setCentralWidget(self._main)
# Create Toolbar and Menubar
toolbar = QToolBar()
toolbar.setMovable(False)
toolbar_fontsize = QFont()
toolbar_fontsize.setPointSize(14)
quit_action = QAction("Close", self)
quit_action.setFont(toolbar_fontsize)
quit_action.setStatusTip("Quit the application")
quit_action.triggered.connect(self.close)
quit_action.setShortcut("ctrl+Q")
toolbar.addAction(quit_action)
# =============================================================
# Start Layout:
layout = QHBoxLayout(self._main)
layout.setContentsMargins(0, 0, 0, 0)
layout.setSpacing(0)
self.line_editor = QLineEdit("3")
self.line_editor.setValidator(QIntValidator(1, 100))
self.line_editor.returnPressed.connect(self.func)
layout.addWidget(self.line_editor)
# Create Table for Pixel Identifications:
pixtab_layout = QVBoxLayout()
label_pixtab_header = QLabel("Pixel Table\n")
label_pixtab_header.setAlignment(Qt.AlignCenter)
self.linetable = QTableWidget()
self.linetable.verticalHeader().hide()
self.linetable.setColumnCount(2)
self.linetable.setHorizontalHeaderLabels(["Pixel", "Wavelength"])
self.linetable.setColumnWidth(0, 80)
self.linetable.setColumnWidth(1, 90)
self.linetable.setFixedWidth(180)
pixtab_layout.addWidget(label_pixtab_header)
pixtab_layout.addWidget(self.linetable)
layout.addLayout(pixtab_layout)
# Create Figure Canvas:
right_layout = QVBoxLayout()
self.fig = Figure(figsize=(6, 6))
self.canvas = FigureCanvas(self.fig)
self.canvas.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding)
self.canvas.updateGeometry()
self.canvas.mpl_connect('key_press_event', self.on_key_press)
self.canvas.setFocusPolicy(Qt.StrongFocus)
self.canvas.setFocus()
right_layout.addWidget(self.canvas)
self.mpl_toolbar = NavigationToolbar(self.canvas, self)
right_layout.addWidget(self.mpl_toolbar)
layout.addLayout(right_layout)
# Plot some random data:
self.ax = self.fig.add_subplot(111)
self.ax.plot([0, 1, 5, 10, 20], [-1, 2, -4, 5, -2])
def on_key_press(self, e):
if e.key == "a":
self.add_point()
def add_point(self):
print("Select point...")
point = self.fig.ginput(1)
x0, _ = point[0]
rowPosition = self.linetable.rowCount()
self.linetable.insertRow(rowPosition)
item = QTableWidgetItem("%.2f" % x0)
item.setFlags(Qt.ItemIsEnabled)
item.setBackground(QColor('lightgray'))
self.linetable.setItem(rowPosition, 0, item)
y_item = QLineEdit("")
y_item.setValidator(QDoubleValidator())
y_item.returnPressed.connect(self.print_val)
self.linetable.setCellWidget(rowPosition, 1, y_item)
self.linetable.cellWidget(rowPosition, 1).setFocus()
def print_val(self):
rowPosition = self.linetable.rowCount()
editor = self.linetable.cellWidget(rowPosition-1, 1)
y_in = float(editor.text())
print(" Table value: %.2f" % y_in)
# and set focus back to canvas:
self.canvas.setFocus()
# Check which widget has focus:
focus_widget = self.focusWidget()
print(focus_widget.__class__)
print("TableWidget has focus? %r" % self.linetable.hasFocus())
print("Cell editor has focus? %r" % editor.hasFocus())
def func(self):
# dome some stuff
print(self.line_editor.text())
# and set focus back to canvas:
self.canvas.setFocus()
if __name__ == '__main__':
# Launch App:
qapp = QApplication(sys.argv)
app = GraphicInterface()
app.show()
qapp.exec_()