关于Toplevel窗口的激活
First窗口有一个名为‘Open’的按钮，按下后会创建并弹出一个名为‘Second’的Topleve窗口，但此时‘Second’窗口并没有处于激活状态（即窗口标题栏是灰色的）。
请问如何使Toplevel窗口在弹出时自动处于激活状态？

程序的代码如下：
from Tkinter import *
class dialog(Frame):
def __init__(self):
Frame.__init__(self)
self.pack()
self.master.geometry('200x100')
self.master.title("First")
button = Button(self,text = 'Open',command = self.OnOpen)
button.pack()

def OnOpen(self):
self.frame = Toplevel()
self.frame.title('Second')

def main():
dialog().mainloop()
if __name__ == "__main__":
main()

[解决办法]
focus()：

Python code

from Tkinter import *class dialog(Frame):    def __init__(self):        Frame.__init__(self)        self.pack()        self.master.geometry('200x100')        self.master.title("First")        button = Button(self,text = 'Open',command = self.OnOpen)        button.pack()    def OnOpen(self):        self.frame = Toplevel()        self.frame.title('Second')        self.frame.focus()def main():    dialog().mainloop()if __name__ == "__main__":    main()