PyQt5 刪除按鈕

Question

在 list_widget 中，我添加了一個添加按鈕，我還想添加一個刪除按鈕，詢問您要刪除哪個項目並刪除所選項目。 我正在嘗試這樣做，但我不知道這樣做。另外，請解釋解決方案我是pyqt5的初學者，或者我想說絕對的初學者。

from PyQt5 import QtWidgets
from PyQt5.QtWidgets import QApplication,QMainWindow, 
QListWidget, QListWidgetItem
import sys

class MyWindow(QMainWindow):
    def __init__(self):
        super(MyWindow, self).__init__()
        self.x = 200
        self.y = 200
        self.width = 500
        self.length = 500
        self.setGeometry(self.x, self.y, self.width, 
        self.length)
        self.setWindowTitle("Stock managment")

        self.iniTUI()

    def iniTUI(self):
        # buttons
        self.b1 = QtWidgets.QPushButton(self)
        self.b1.setText("+")
        self.b1.move(450, 100)
        self.b1.resize(50, 25)
        self.b1.clicked.connect(self.take_inputs)
        # This is the button I want to define.
        self.btn_minus = QtWidgets.QPushButton(self)
        self.btn_minus.setText("-")
        self.btn_minus.move(0, 100)
        self.btn_minus.resize(50, 25)


        # list
        self.list_widget = QListWidget(self)

        self.list_widget.setGeometry(120, 100, 250, 300)

        self.item1 = QListWidgetItem("A")
        self.item2 = QListWidgetItem("B")
        self.item3 = QListWidgetItem("C")

        self.list_widget.addItem(self.item1)
        self.list_widget.addItem(self.item2)
        self.list_widget.addItem(self.item3)

        self.list_widget.setCurrentItem(self.item2)



    def take_inputs(self):
        self.name, self.done1 = 
 QtWidgets.QInputDialog.getText(
            self, 'Add Item to List', 'Enter The Item you want 
in 
            the list:')
        self.roll, self.done2 = QtWidgets.QInputDialog.getInt(
            self, f'Quantity of {str(self.name)}', f'Enter 
            Quantity of {str(self.name)}:')

        if self.done1 and self.done2:
            self.item4 = QListWidgetItem(f"{str(self.name)}              
            Quantity{self.roll}")
            self.list_widget.addItem(self.item4)
            self.list_widget.setCurrentItem(self.item4)
               

    def clicked(self):
        self.label.setText("You clicked the button")
        self.update()

    def update(self):
        self.label.adjustSize()


def clicked():
    print("meow")
def window():
    apk = QApplication(sys.argv)
    win = MyWindow()





    win.show()
    sys.exit(apk.exec_())
window()

Answer 1

這里的核心問題是缺乏視圖和數據的分離。 這使得很難推理如何使用圖形元素。 您幾乎肯定會想要遵循模型視圖控制器設計范式https://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller ，它提供了一種處理這種分離的系統方法。

一旦你這樣做了，如何繼續這個問題就會變得非常簡單：你本質上只有一個列表，你要么想在這個列表中添加一個東西，要么根據選擇刪除一個。

我在這里包含一個例子，它碰巧使用了 Qt5 中的內置類 QStringListModel 和 QListView，但是編寫自己的更專業的小部件和模型很簡單。 它們都只是使用一個簡單的信號向視圖發出它需要刷新活動信息的信號。

from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
import sys

class StuffViewer(QMainWindow):
    def __init__(self, model):
        super().__init__()
        self.setWindowTitle("Stock managment")

        # 1: Use layouts.
        hbox = QHBoxLayout()
        widget = QWidget()
        widget.setLayout(hbox)
        self.setCentralWidget(widget)

        # 2: Don't needlessly store things in "self"
        vbox = QVBoxLayout()
        add = QPushButton("+")
        add.clicked.connect(self.add_new_stuff)
        vbox.addWidget(add)
        sub = QPushButton("-")
        sub.clicked.connect(self.remove_selected_stuff)
        vbox.addWidget(sub)
        vbox.addStretch(1)
        hbox.addLayout(vbox)

        # 3: Separate the view of the data from the data itself. Use Model-View-Controller design to achieve this.
        self.model = model
        self.stuffview = QListView()
        self.stuffview.setModel(self.model)
        hbox.addWidget(self.stuffview)

    def add_new_stuff(self):
        new_stuff, success = QInputDialog.getText(self, 'Add stuff', 'Enter new stuff you want')
        if success:
            self.stuff.setStringList(self.stuff.stringList() + [new_stuff])

    def remove_selected_stuff(self):
        index = self.stuffview.currentIndex()
        all_stuff = self.stuff.stringList()
        del all_stuff[index.column()]
        self.stuff.setStringList(all_stuff)


def window():
    apk = QApplication(sys.argv)
    # Data is clearly separated:
    # 4: Never enumerate variables! Use lists!
    stuff = QStringListModel(["Foo", "Bar", "Baz"])
    # The graphical components is just how you interface with the data with the user!
    win = StuffViewer(stuff)
    win.show()
    sys.exit(apk.exec_())

window()