python - 尝试将 QLayout ""添加到 QWidget ""，它已经有一个布局

Question

当我想将 QWidget 添加到 QGridLayout 时出现错误。

我是 PyQt 的新手，之前我创建了一个简单的 GUI 而不使用类，但现在我想尝试在 python 中使用类创建一个简单的图形用户界面，虽然这让我感到困惑，但我得到了这个错误

QLayout:尝试将 QLayout“”添加到已经有布局的 QWidget“”

QLayout::addChildLayout: layout "" already has a parent

这是我之前没有类的作品

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *

class MyClass(object):
    def __init__(self, device_type=None, ip=None, username=None, password=None, secret=None, command=None):
        self.device_type = device_type
        self.ip = ip
        self.username = username
        self.password = password
        self.secret = secret
        self.command = command

device_list = []
#ip_list = []

def addDevice():
    device_type = str(cb_device_list.currentText())
    ip = le_ip.text()
    username = le_username.text()
    password = le_password.text()
    secret = le_enable.text()
    command = 'show tech'
    device_list.append(MyClass(device_type, ip, username, password, secret, command))
    #ip_list.append(ip)
    combobox_ip_list.addItem(ip)# Add Ip to ComboBox

    for list in device_list:
        print(list.device_type)

##################################
app = QApplication(sys.argv)
QApplication.processEvents()
app.setStyle('cleanlooks')
window = QWidget()
window.setWindowTitle("Network Automation")
############################# Input IP

# Device Type
lb_device_list = QLabel(window)
lb_device_list.setText('Device Type')
cb_device_list = QComboBox(window)
cb_device_list.addItem('cisco_ios')
cb_device_list.addItem('cisco_s300')

lb_ip = QLabel(window)
bt = QPushButton(window)
btadd = QPushButton(window)

# Ip Device
lb_ip.setText('IP Address')
le_ip = QLineEdit(window)
le_ip.setText('')
le_ip.setPlaceholderText('Input Device IP')
le_ip.setFixedWidth(150)

# username
lb_username = QLabel(window)
le_username = QLineEdit(window)
lb_username.setText('Username')
le_username.setText('')
le_username.setPlaceholderText('Input Username')
le_username.setFixedWidth(150)

# password
lb_password = QLabel(window)
le_password = QLineEdit(window)
lb_password.setText('Password')
le_password.setText('')
le_password.setPlaceholderText('Input Password')
le_password.setFixedWidth(150)

# Privilage Password
lb_enable = QLabel(window)
lb_enable.setText('Privilege Mode Password')
le_enable = QLineEdit(window)
le_enable.setText('')
le_enable.setPlaceholderText('Input Enable Password')
le_enable.setFixedWidth(150)

bt.setText('Generate')
bt.setFixedWidth(70)

btadd.setText('Add')

line = QFrame(window)
line.setFrameShape(QFrame.VLine)
line.setFrameShadow(QFrame.Sunken)
line.setLineWidth(3)

########################### Layout Ip Device List

lb3 = QLabel(window)
lb3.setText('IP Device List')
combobox_ip_list = QComboBox(window)
combobox_ip_list.setFixedWidth(170)
#combobox_ip_list.addItems(ip_list)

############################## SubLayout and Layout
hblayout = QHBoxLayout()
hblayout.addWidget(bt)
hblayout.addWidget(btadd)

sublayout = QVBoxLayout()
sublayout.addWidget(lb_device_list)
sublayout.addWidget(cb_device_list)
sublayout.addWidget(lb_ip)
sublayout.addWidget(le_ip)
sublayout.addWidget(lb_username)
sublayout.addWidget(le_username)
sublayout.addWidget(lb_password)
sublayout.addWidget(le_password)
sublayout.addWidget(lb_enable)
sublayout.addWidget(le_enable)
sublayout.addLayout(hblayout)

sublayout2 = QVBoxLayout()
sublayout2.addWidget(lb3)
sublayout2.addWidget(combobox_ip_list)
sublayout2.addStretch(1)

layout = QGridLayout(window)
layout.addLayout(sublayout,0,0)
layout.addWidget(line,0,1)
layout.addLayout(sublayout2,0,2)

btadd.clicked.connect(addDevice)

window.show()
sys.exit(app.exec_())

现在使用类(错误)

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *

class Window(QMainWindow,QWidget):
    def __init__(self):
        QMainWindow.__init__(self)
        self.setWindowTitle('Network Automation')
        self.window = QWidget(self)
        self.lb_device_list = QLabel('Device Type',self.window)
        self.cb_device_list = QComboBox(self.window)
        self.cb_device_list.addItem('cisco_ios')
        self.cb_device_list.addItem('cisco_s300')

        self.vbox = QVBoxLayout(self.window)
        self.vbox.addWidget(self.lb_device_list)
        self.vbox.addWidget(self.cb_device_list)

        self.layout = QGridLayout(self.window)
        self.layout.addLayout(self.vbox,0,0)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    myapp = Window()
    myapp.show()
    sys.exit(app.exec_())

我需要像以前使用类一样创建简单的图形用户界面

Answer 1

放置 some_layout(some_widget) 类似于 some_widget.setLayout(some_layout)，所以在每个布局中你都将它添加到 self.window。

此外，MainWindow 已经有一个默认布局，因为它有某些默认小部件，如 QStatusBar 和 QMenubar，所以你不应该以这种方式添加它，你应该将它添加到 centralWidget，在你的情况下它可能是 self.window。

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *

class Window(QMainWindow):
    def __init__(self):
        QMainWindow.__init__(self)
        widget = QWidget(self)
        self.setCentralWidget(widget)
        self.setWindowTitle('Network Automation')
        self.lb_device_list = QLabel('Device Type')
        self.cb_device_list = QComboBox()
        self.cb_device_list.addItem('cisco_ios')
        self.cb_device_list.addItem('cisco_s300')

        self.vbox = QVBoxLayout()
        self.vbox.addWidget(self.lb_device_list)
        self.vbox.addWidget(self.cb_device_list)

        self.layout = QGridLayout()
        self.layout.addLayout(self.vbox,0,0)
        widget.setLayout(self.layout)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    myapp = Window()
    myapp.show()
    sys.exit(app.exec_())

另一个观察，你不应该同时继承QMainWindow和QWidget，因为QMainWindow继承自QWidget，这是不必要的

另一种选择是实现一个继承自 QWidget 的类，而不是 QMainWindow。

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *

class Window(QWidget):
    def __init__(self):
        QWidget.__init__(self)
        self.setWindowTitle('Network Automation')
        self.lb_device_list = QLabel('Device Type')
        self.cb_device_list = QComboBox()
        self.cb_device_list.addItem('cisco_ios')
        self.cb_device_list.addItem('cisco_s300')

        self.vbox = QVBoxLayout()
        self.vbox.addWidget(self.lb_device_list)
        self.vbox.addWidget(self.cb_device_list)

        self.layout = QGridLayout()
        self.layout.addLayout(self.vbox,0,0)
        self.setLayout(self.layout)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    myapp = Window()
    myapp.show()
    sys.exit(app.exec_())

我还将您实现的代码转换为继承自 QWidget 的类:

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *

class Widget(QWidget):
    def __init__(self, parent=None):
        QWidget.__init__(self, parent=parent)
        self.device_list = []
        self.setWindowTitle("Network Automation")
        ############################# Input IP

        # Device Type
        lb_device_list = QLabel(self)
        lb_device_list.setText('Device Type')
        self.cb_device_list = QComboBox(self)
        self.cb_device_list.addItem('cisco_ios')
        self.cb_device_list.addItem('cisco_s300')

        lb_ip = QLabel(self)
        bt = QPushButton(self)
        btadd = QPushButton(self)

        # Ip Device
        lb_ip.setText('IP Address')
        self.le_ip = QLineEdit(self)
        self.le_ip.setText('')
        self.le_ip.setPlaceholderText('Input Device IP')
        self.le_ip.setFixedWidth(150)

        # username
        lb_username = QLabel(self)
        self.le_username = QLineEdit(self)
        lb_username.setText('Username')
        self.le_username.setText('')
        self.le_username.setPlaceholderText('Input Username')
        self.le_username.setFixedWidth(150)

        # password
        lb_password = QLabel(self)
        self.le_password = QLineEdit(self)
        lb_password.setText('Password')
        self.le_password.setText('')
        self.le_password.setPlaceholderText('Input Password')
        self.le_password.setFixedWidth(150)

        # Privilage Password
        lb_enable = QLabel(self)
        lb_enable.setText('Privilege Mode Password')
        self.le_enable = QLineEdit(self)
        self.le_enable.setText('')
        self.le_enable.setPlaceholderText('Input Enable Password')
        self.le_enable.setFixedWidth(150)

        bt.setText('Generate')
        bt.setFixedWidth(70)

        btadd.setText('Add')

        line = QFrame(self)
        line.setFrameShape(QFrame.VLine)
        line.setFrameShadow(QFrame.Sunken)
        line.setLineWidth(3)

        ########################### Layout Ip Device List

        lb3 = QLabel(self)
        lb3.setText('IP Device List')
        self.combobox_ip_list = QComboBox(self)
        self.combobox_ip_list.setFixedWidth(170)
        #combobox_ip_list.addItems(ip_list)

        ############################## SubLayout and Layout
        hblayout = QHBoxLayout()
        hblayout.addWidget(bt)
        hblayout.addWidget(btadd)

        sublayout = QVBoxLayout()
        sublayout.addWidget(lb_device_list)
        sublayout.addWidget(self.cb_device_list)
        sublayout.addWidget(lb_ip)
        sublayout.addWidget(self.le_ip)
        sublayout.addWidget(lb_username)
        sublayout.addWidget(self.le_username)
        sublayout.addWidget(lb_password)
        sublayout.addWidget(self.le_password)
        sublayout.addWidget(lb_enable)
        sublayout.addWidget(self.le_enable)
        sublayout.addLayout(hblayout)

        sublayout2 = QVBoxLayout()
        sublayout2.addWidget(lb3)
        sublayout2.addWidget(self.combobox_ip_list)
        sublayout2.addStretch(1)

        layout = QGridLayout(self)
        layout.addLayout(sublayout,0,0)
        layout.addWidget(line,0,1)
        layout.addLayout(sublayout2,0,2)

        btadd.clicked.connect(self.addDevice)

    def addDevice(self):
        device_type = str(self.cb_device_list.currentText())
        ip = self.le_ip.text()
        username = self.le_username.text()
        password = self.le_password.text()
        secret = self.le_enable.text()
        command = 'show tech'
        self.device_list.append(MyClass(device_type, ip, username, password, secret, command))
        #ip_list.append(ip)
        self.combobox_ip_list.addItem(ip)# Add Ip to ComboBox

        for list in self.device_list:
            print(list.device_type)

class MyClass(object):
    def __init__(self, device_type=None, ip=None, username=None, password=None, secret=None, command=None):
        self.device_type = device_type
        self.ip = ip
        self.username = username
        self.password = password
        self.secret = secret
        self.command = command
#ip_list = []



##################################
app = QApplication(sys.argv)
QApplication.processEvents()
app.setStyle('cleanlooks')
window = Widget()
window.show()
sys.exit(app.exec_())