将焦点放在 QlineEdit 小部件上

Question

我正在尝试组合一个简单的小部件，其中焦点自动放在 QLineEdit 小部件上（它用于条形码扫描仪输入，我不希望最终用户必须单击小部件）。

相关代码如下：

from qtmodern import styles, windows
from qtpy import QtGui, QtCore
from qtpy.QtWidgets import *
from qtpy.QtCore import Qt

class MyGui(QWidget):
    def __init__(self, parent=None):
        super(MyGui, self).__init__(parent)

        layout = QVBoxLayout()

        self.lineEdit = QLineEdit(self)
        self.lineEdit.setPlaceholderText('foobar')  
        self.lineEdit.setFocusPolicy(Qt.StrongFocus)      
        self.lineEdit.setFocus()

        layout.addWidget(self.lineEdit)

        self.setLayout(layout)
        self.show()

def main():
    app = QApplication([])
    styles.dark(app)

    g = windows.ModernWindow(MyGui())
    g.resize(350,100)
    location = (50, 100)
    g.move(location[0], location[1])
    g.setWindowTitle('SmallTest')

    g.show()
    app.exec_()

if __name__ == '__main__':
   main()

它不想将焦点放在 lineEdit 小部件上。我猜这是我错过的非常明显的东西，但我已经挖了一段时间试图找到它，但还没有偶然发现它。

Answer 1

小部件显示后必须使用setFocus()。

from qtmodern import styles, windows
from qtpy import QtGui, QtCore
from qtpy.QtWidgets import *
from qtpy.QtCore import Qt

class MyGui(QWidget):
    def __init__(self, parent=None):
        super(MyGui, self).__init__(parent)
        layout = QVBoxLayout(self)
        self.lineEdit = QLineEdit(self)
        self.lineEdit.setPlaceholderText('foobar')  
        self.lineEdit.setFocusPolicy(Qt.StrongFocus)
        layout.addWidget(self.lineEdit)

def main():
    app = QApplication([])
    styles.dark(app)
    gui = MyGui()
    g = windows.ModernWindow(gui)
    g.resize(350,100)
    location = (50, 100)
    g.move(*location)
    g.setWindowTitle('SmallTest')
    g.show()
    gui.lineEdit.setFocus()
    app.exec_()

if __name__ == '__main__':
   main()