python - wxPython 中的按钮事件出现错误

Question

我面临以下问题 - 每当我尝试为任何按钮创建事件监听器时，我都会收到以下错误:

    self.button_compute.Bind(wx.EVT_BUTTON, self.on_click)
    AttributeError: 'BMICalculator' object has no attribute 'button_compute'

我尝试了此线程中建议的解决方案:AttributeError: 'module' object has no attribute 'PyScrolledWindow' in wxPython ，但它对我不起作用。

该程序用于计算 BMI，代码如下:

import wx

class BMICalculator(wx.Frame):
    def __init__(self, parent, id):
        wx.Frame.__init__(self, parent, id, "BMI calculator", (600, 800))
        panel = wx.Panel(self)
        self.Centre()
        #Creating the buttons and text fields
        static_text_height = wx.StaticText(panel, -1, "Height", (170, 10))
        height = wx.SpinCtrl(panel, -1, pos=(164, 40), size=(60, -1))
        static_text_weight = wx.StaticText(panel, -1, "Weight", (170, 100))
        weight = wx.SpinCtrl(panel, -1, pos=(164, 130), size=(60, -1))

        button_compute = wx.Button(panel, label="Compute", pos=(110, 180), size=(60, -1))
        button_cancel = wx.Button(panel, label="Cancel", pos=(210, 180), size=(60, -1))

        result_text = wx.StaticText(panel, -1, "Enter your height and weight and press compute", (68, 220))
        #Adding the events for the buttons (Where I get the error)
        self.button_compute.Bind(wx.EVT_BUTTON, self.on_click)

        self.button_cancel.Bind(wx.EVT_CLOSE, self.click_close)

    def compute_BMI(height, weight):
        #BMI = x KG / (y M *  y M)
        height_m = height/100
        BMI = weight/(height_m *  height_m)
        return BMI

    def click_close(self, event):
        self.Close(True)

    def on_click(self, event):
        result_text.SetValue(compute_BMI(height.GetValue(), weight.GetValue()))

def main():
    app = wx.App()
    frame = BMICalculator(None, -1)
    frame.Show()
    app.MainLoop()
    enter code here

if __name__ == '__main__':
    main()

任何帮助将不胜感激!

Answer 1

当您创建 button_compute 时，您将其保留为函数的局部变量。当您尝试绑定(bind)事件时，您将尝试读取尚未创建的实例属性。实际上，您在很多情况下都会这样做，但您的脚本在第一个情况下就会出错。将 self.xxx 添加到您的赋值中，以便为函数创建实例属性而不是局部变量。

import wx

class BMICalculator(wx.Frame):
    def __init__(self, parent, id):
        wx.Frame.__init__(self, parent, id, "BMI calculator", (600, 800))
        self.panel = wx.Panel(self)
        self.Centre()
        #Creating the buttons and text fields
        self.static_text_height = wx.StaticText(self.panel, -1, "Height", (170, 10))
        self.height = wx.SpinCtrl(self.panel, -1, pos=(164, 40), size=(60, -1))
        self.static_text_weight = wx.StaticText(self.panel, -1, "Weight", (170, 100))
        self.weight = wx.SpinCtrl(self.panel, -1, pos=(164, 130), size=(60, -1))

        self.button_compute = wx.Button(self.panel, label="Compute", pos=(110, 180), size=(60, -1))
        self.button_cancel = wx.Button(self.panel, label="Cancel", pos=(210, 180), size=(60, -1))

        self.result_text = wx.StaticText(self.panel, -1, "Enter your height and weight and press compute", (68, 220))
        #Adding the events for the buttons (Where I get the error)
        self.button_compute.Bind(wx.EVT_BUTTON, self.on_click)

        self.button_cancel.Bind(wx.EVT_CLOSE, self.click_close)

    def compute_BMI(height, weight):
        #BMI = x KG / (y M *  y M)
        height_m = height/100
        BMI = weight/(height_m *  height_m)
        return BMI

    def click_close(self, event):
        self.Close(True)

    def on_click(self, event):
        self.result_text.SetValue(self.compute_BMI(self.height.GetValue(), self.weight.GetValue()))

def main():
    app = wx.App()
    frame = BMICalculator(None, -1)
    frame.Show()
    app.MainLoop()
    #enter code here

if __name__ == '__main__':
    main()