记PyQt5信号的一个坑

心已赠人 2023-02-09 11:51 1阅读 0赞

最近在用PyQt5做项目的时候偶然发现了一个小BUG，BUG虽小，可有时候往往就是最致命的一击。这里分享一下，希望大家不要踩坑。先看下面一个例子:

# -*- coding: utf-8 -*-
    from PyQt5.QtWidgets import QWidget,QHBoxLayout,QLabel,QPushButton,QApplication,QVBoxLayout
    from PyQt5.QtCore import  pyqtSignal
    from functools import  partial
    
    class test_PyQt_Bug(QWidget):
        long_int_signal = pyqtSignal(int)
        def __init__(self):
            super(test_PyQt_Bug, self).__init__()
            self.setGeometry(600,300,500,500)
            self.ini_ui()
    
        def ini_ui(self):
            main_layout = QHBoxLayout()
            main_layout.setSpacing(100)
            btn_layout = QVBoxLayout()
            btn_layout.setSpacing(50)
            self.send_btn = QPushButton("发送按钮1")
            self.send_btn.setObjectName("send_btn")
            self.send_btn2 = QPushButton("发送按钮2")
            self.send_btn2.setObjectName("send_btn2")
            btn_layout.addWidget(self.send_btn)
            btn_layout.addWidget(self.send_btn2)
            self.number_label = QLabel()
            main_layout.addLayout(btn_layout)
            main_layout.addWidget(self.number_label)
            self.setLayout(main_layout)
    
            #按钮信号发送
            self.send_btn.clicked.connect(self.send_btn_slot)
            self.send_btn.clicked.connect(partial(self.show_number_slot,id(self.send_btn)))
    
            #普通信号发送
            self.long_int_signal.connect(self.show_number_slot)
            self.send_btn2.clicked.connect(self.send_btn2_slot)
    
        def send_btn_slot(self):
            self.signal_sender = "按钮1内置信号"
    
        def send_btn2_slot(self):
            self.signal_sender = "PyQt5普通信号"
            self.long_int_signal.emit(id(self.send_btn))
    
        def show_number_slot(self,number):
            sender = self.signal_sender
            number1 = id(self.send_btn)
            number2 = number
            self.number_label.setText("发送人:{} \n\n正确的数字是: {}\n\n接收到的数字是: {}".format(sender,number1,number2))
    
    
    if __name__ == "__main__":
        import sys
        app = QApplication(sys.argv)
        test_win = test_PyQt_Bug()
        test_win.show()
        sys.exit(app.exec_())

运行结果

![图像无法显示][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2RhaW1hc2hpcmVu_size_16_color_FFFFFF_t_70]

![图像无法显示][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2RhaW1hc2hpcmVu_size_16_color_FFFFFF_t_70 1]

可以看到，同样是发送一长串的整数，PyQt5内置的按钮信号工作正常，而我们自定义的整型数字信号却把数字改了，说明数据在传输的过程中受到了修改，严重影响数据安全，所以要慎用这样的写法，目前原因我没有找到，因为理论上，Python中的整型数据类型是没有大小限制的，这应该是PyQt的问题,知道的朋友可以在下面留言。

为了找到能正确传输的最大数字大小范围，我还用下面这几个数字多做了几次实验：

>  *  123456789
>  *  1234567891
>  *  12345678910
>  *  2222222222

运行结果如下:

![无][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2RhaW1hc2hpcmVu_size_16_color_FFFFFF_t_70 2]![无][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2RhaW1hc2hpcmVu_size_16_color_FFFFFF_t_70 3]![无][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2RhaW1hc2hpcmVu_size_16_color_FFFFFF_t_70 4]

发现整型信号正确传输的最大位数不能超过10位数,而且不能大于2222222222，具体最大是多少，还不知道，有机会可以写个循环找，哈哈哈，如果你找到了，记得告诉我！

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