使用 QSignalMapper [英] Using QSignalMapper

问题描述

我试着做一个简单的例子来帮助理解 QSignalMapping 的概念在 PySide 中是如何工作的.我想通过循环迭代来动态创建一系列按钮，当用户按下其中一个按钮时，我可以激活一个方法，为按下的按钮返回适当的标签.

from PySide2 import QtWidgets,QtCore,QtGuiFruit_list = [苹果"，橙子"，梨"]def Fruit_button_event():打印这是按下按钮的标签"定义主():对于fruit_list 中的水果:Fruit_button = QtWidgets.QPushButton(fruit)Fruit_button.clicked.connect(lambda:fruit_button_event())主要的()

解决方案

在下一部分中，我将展示如何使用 QSignalMapper 的示例:

from PySide2 import QtCore, QtWidgets类小部件(QtWidgets.QWidget):def __init__(self, parent=None):super(Widget, self).__init__(parent)躺 = QtWidgets.QVBoxLayout(self)Fruit_list = [苹果"，橙子"，梨"]映射器 = QtCore.QSignalMapper(self)mapper.mapped[str].connect(self.fruit_button_event)对于fruit_list 中的水果:btn = QtWidgets.QPushButton(fruit)btn.clicked.connect(mapper.map)mapper.setMapping(btn，水果)Lay.addWidget(btn)@QtCore.Slot(str)def Fruit_button_event(self, text):打印(这是按下按钮的标签"，文本)如果 __name__ == '__main__':导入系统app = QtWidgets.QApplication(sys.argv)w = 小部件()w.show()sys.exit(app.exec_())

请记住，Qt 5.10 QSignalMapper 已弃用:><块引用>

这个类已经过时了.提供它以保留旧的源代码在职的.我们强烈建议不要在新代码中使用它.

<小时>

python 中的相同功能可以通过 functools.partial(...) 获得:

from PySide2 import QtCore, QtWidgets从 functools 导入部分类小部件(QtWidgets.QWidget):def __init__(self, parent=None):super(Widget, self).__init__(parent)躺 = QtWidgets.QVBoxLayout(self)Fruit_list = [苹果"，橙子"，梨"]对于fruit_list 中的水果:btn = QtWidgets.QPushButton(fruit)btn.clicked.connect(partial(self.fruit_button_event,fruit))Lay.addWidget(btn)@QtCore.Slot(str)def Fruit_button_event(self, text):打印(这是按下按钮的标签"，文本)

或者使用 lambda:

btn.clicked.connect(lambda text=fruit: self.fruit_button_event(text))

或 QButtonGroup:

类小部件(QtWidgets.QWidget):def __init__(self, parent=None):super(Widget, self).__init__(parent)躺 = QtWidgets.QVBoxLayout(self)Fruit_list = [苹果"，橙子"，梨"]group = QtWidgets.QButtonGroup(self)group.buttonClicked.connect(self.OnButtonClicked)对于fruit_list 中的水果:btn = QtWidgets.QPushButton(fruit)group.addButton(btn)Lay.addWidget(btn)@QtCore.Slot(QtWidgets.QAbstractButton)def OnButtonClicked(self, btn):print("这是按下按钮的标签", btn.text())

I tried to make a simple example to help understand how the concept of QSignalMapping works in PySide. I would like to dynamically create a series of buttons by iterating through a loop, and when the user pushes one of the buttons, I can activate a method that returns the appropriate label for the button that was pressed.

from PySide2 import QtWidgets,QtCore,QtGui

fruit_list = ["apples","oranges","pears"]

def fruit_button_event():
    print "this is the pressed button's label"

def main():
    for fruit in fruit_list:
        fruit_button = QtWidgets.QPushButton(fruit)
        fruit_button.clicked.connect(lambda:fruit_button_event())
main()

解决方案

In the next part I show an example how to use QSignalMapper:

from PySide2 import QtCore, QtWidgets


class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Widget, self).__init__(parent)
        lay = QtWidgets.QVBoxLayout(self)

        fruit_list = ["apples","oranges","pears"]
        mapper =  QtCore.QSignalMapper(self)
        mapper.mapped[str].connect(self.fruit_button_event)

        for fruit in fruit_list:
            btn = QtWidgets.QPushButton(fruit)
            btn.clicked.connect(mapper.map)
            mapper.setMapping(btn, fruit)
            lay.addWidget(btn)

    @QtCore.Slot(str)
    def fruit_button_event(self, text):
        print("this is the pressed button's label", text)


if __name__ == '__main__':
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = Widget()
    w.show()
    sys.exit(app.exec_())

Remember that from Qt 5.10 QSignalMapper is deprecated:

This class is obsolete. It is provided to keep old source code working. We strongly advise against using it in new code.

---

The same functionality in python can be obtained with functools.partial(...):

from PySide2 import QtCore, QtWidgets
from functools import partial


class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Widget, self).__init__(parent)
        lay = QtWidgets.QVBoxLayout(self)

        fruit_list = ["apples","oranges","pears"]

        for fruit in fruit_list:
            btn = QtWidgets.QPushButton(fruit)
            btn.clicked.connect(partial(self.fruit_button_event, fruit))
            lay.addWidget(btn)

    @QtCore.Slot(str)
    def fruit_button_event(self, text):
        print("this is the pressed button's label", text)

Or with lambda:

btn.clicked.connect(lambda text=fruit: self.fruit_button_event(text))

Or QButtonGroup:

class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Widget, self).__init__(parent)
        lay = QtWidgets.QVBoxLayout(self)

        fruit_list = ["apples","oranges","pears"]
        group = QtWidgets.QButtonGroup(self)
        group.buttonClicked.connect(self.OnButtonClicked)

        for fruit in fruit_list:
            btn = QtWidgets.QPushButton(fruit)
            group.addButton(btn)
            lay.addWidget(btn)

    @QtCore.Slot(QtWidgets.QAbstractButton)
    def OnButtonClicked(self, btn):
        print("this is the pressed button's label", btn.text())

这篇关于使用 QSignalMapper的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！