python - 使用 Tkinter 实现密码对话框

Question

我正在尝试实现一个获取用户密码的对话框。我创建了从 tk.Toplevel 继承的类 PasswordDiaglog ，但这会导致其执行不阻塞父框架的问题。

import Tkinter as tk

class PasswordDialog(tk.Toplevel):
    def __init__(self, parent):
        tk.Toplevel.__init__(self)
        self.password = None
        self.entry = tk.Entry(self, show='*')
        self.entry.pack()
        self.button = tk.Button(self)
        self.button["text"] = "Submit"
        self.button["command"] = self.StorePass
        self.button.pack()

    def StorePass(self):
        self.password = self.entry.get()
        self.destroy()
        print '1: Password was', self.password

class MainApplication(tk.Frame):
    def __init__(self, root):
        tk.Frame.__init__(self, root)
        self.button = tk.Button(self)
        self.button["text"] = "Password"
        self.button["command"] = self.GetPassword
        self.button.pack()

    def GetPassword(self):
        passwd = PasswordDialog(self)
        # HALT HERE 
        print '2: Password was', passwd.password

if __name__ == "__main__":
    root = tk.Tk()
    MainApplication(root).pack(side="top", fill="both", expand=True)
    root.mainloop()

通过运行我的代码并提交 foobar 作为密码，可以在终端中看到以下输出:

2: Password was None
1: Password was foobar

预期输出应该是:

1: Password was foobar
2: Password was foobar

关于如何解决这个问题或如何实现一般密码对话框有什么想法吗？

最好在输入 entry 后按回车键来调用 StoredPass()。

Answer 1

将密码存储为 MainAplication 类的属性，并使用传入的 parent 作为 PasswordDialog 类的句柄意味着您可以使用self.wait_window(PasswordDialog(self)) 阻止执行，直到 PasswordDialog 被销毁:

import Tkinter as tk

class PasswordDialog(tk.Toplevel):
    def __init__(self, parent):
        tk.Toplevel.__init__(self)
        self.parent = parent
        self.entry = tk.Entry(self, show='*')
        self.entry.bind("<KeyRelease-Return>", self.StorePassEvent)
        self.entry.pack()
        self.button = tk.Button(self)
        self.button["text"] = "Submit"
        self.button["command"] = self.StorePass
        self.button.pack()

    def StorePassEvent(self, event):
        self.StorePass()

    def StorePass(self):
        self.parent.password = self.entry.get()
        self.destroy()
        print '1: Password was', self.parent.password

class MainApplication(tk.Frame):
    def __init__(self, root):
        tk.Frame.__init__(self, root)
        self.password = None
        self.button = tk.Button(self)
        self.button["text"] = "Password"
        self.button["command"] = self.GetPassword
        self.button.pack()

    def GetPassword(self):
        self.wait_window(PasswordDialog(self))
        print '2: Password was', self.password

if __name__ == "__main__":
    root = tk.Tk()
    MainApplication(root).pack(side="top", fill="both", expand=True)
    root.mainloop()

输出现在符合预期:

1: Password was foobar
2: Password was foobar

---

要绑定(bind) Return 键，您可以使用:

self.entry.bind("<KeyRelease-Return>", self.StorePassEvent)

使用包装函数:

def StorePassEvent(self, event):
    self.StorePass()

您还可以使用 lambda 代替:

self.entry.bind("<KeyRelease-Return>", lambda x: self.StorePass())