如何捕获Key_tab事件 [英] How to capture the Key_tab event

问题描述

我正在尝试捕获key_tab事件，但是没有运气.我意识到只有在没有其他小部件的情况下它才起作用，因此光标没有地方可以去，只有这样我才能使事件返回.这是一个简化的代码示例.

i am trying to capture the key_tab event, but no luck. i realized that it only works if there are no other widgets so the cursor has no where to go only then can i get the event to return. here is a simplified code sample.

class MyCombo(QComboBox):

    def __init__(self, parent=None):
        super(MyCombo, self).__init__(parent)
        self.setEditable(True)

    def keyPressEvent(self, event):
        if (event.type() == QEvent.KeyPress) and (event.key() == Qt.Key_Tab):
            print "tab pressed"
        elif event.key() == Qt.Key_Return:
            print "return pressed"
        else:
            QComboBox.keyPressEvent(self, event)

class Form_1(QDialog):

    def __init__(self, parent=None):
        super(Form_1, self).__init__(parent)
        self.combo = MyCombo()
        self.line = QLineEdit()
        layout = QVBoxLayout()
        layout.addWidget(self.combo)
        layout.addWidget(self.line)
        self.setLayout(layout)

app = QApplication(sys.argv)
form = Form_1()
form.show()
app.exec_()

如果我将以下两行注释掉

if i comment out the following two lines

self.line = QLineEdit()
layout.addWidget(self.line)

然后它可以正常工作，因为表单上只剩下一个小部件.

then it works fine, because there is only one widget left on the form.

我要去哪里错了?

干杯，乔

推荐答案

很显然，Key_Tab按下事件从未传递给任何处理程序，而是传递给setFocus()，因此，为了拦截Key_Tab事件，我们需要实现事件( )方法本身. 所以这是新代码:

Apparently the Key_Tab press event is never passed to any handler but to the setFocus() so in order to intercept the Key_Tab event, we need to implement the event() method itself. so here is the new code:

class MyCombo(QComboBox):

    def __init__(self, parent=None):
        super(MyCombo, self).__init__(parent)
        self.setEditable(True)

    def keyPressEvent(self, event):
        if event.key() == Qt.Key_Return:
            print "return pressed"
        else:
            QComboBox.keyPressEvent(self, event)

    def event(self, event):
        if event.type() == QEvent.KeyPress and event.key() == Qt.Key_Tab:
            print "tab pressed"
            return False
        return QWidget.event(self, event)

class Form_1(QDialog):

    def __init__(self, parent=None):
        super(Form_1, self).__init__(parent)
        self.combo = MyCombo()
        self.line = QLineEdit()
        layout = QVBoxLayout()
        layout.addWidget(self.combo)
        layout.addWidget(self.line)
        self.setLayout(layout)

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