Tkinter学习笔记-2

事件处理模型

GUI组件根据用户的交互情况生成事件

异步事件驱动的程序：程序将事件绑定到图形组件上，并实现了事件的处理程序（回调函数）来处理GUI事件

文本框

用于输入文本，程序员用来显示文本

通过Entry类创建

用户按下Enter键触发Entry组件的<Return>事件

# SimpleEntry.py
# Entry compnents and event binding demonstration

from Tkinter import *
from tkMessageBox import *

class EntryDemo( Frame ):
    """ Demonstrate Entrys and Event binding """

    def __init__(self):
        """ Create, pack and bind events to four Entrys """

        Frame.__init__( self )
        self.pack( expand = YES, fill = BOTH )
        self.master.title( "Testing Entry Components" )
        self.master.geometry( "325x100" ) # width x length

        self.frame1 = Frame( self )
        self.frame1.pack( pady = 5 )

        self.text1 = Entry( self.frame1, name = "text1" )

        # bind the Entry component to event
        self.text1.bind( "<Return>", self.showContents )
        self.text1.pack( side = LEFT, padx = 5 )

        self.text2 = Entry( self.frame1, name = "text2" )

        # insert text into Entry component text2
        self.text2.insert( INSERT, "Enter text here" )
        self.text2.bind("<Return>", self.showContents )
        self.text2.pack( side = LEFT, padx = 5 )

        self.frame2 = Frame( self )
        self.frame2.pack( pady = 5 )

        self.text3 = Entry( self.frame2, name = "text3" )
        self.text3.insert( INSERT, "Uneditable text field" )

        # prohibit user from altering text in Entry component text3
        self.text3.config( state = DISABLED )
        self.text3.bind("<Return>", self.showContents )
        self.text3.pack( side = LEFT, padx = 5 )

        # text in Entry component text4 appears as *
        self.text4 = Entry(self.frame2, name = "text4", show = "*" )
        self.text4.bind("<Return>", self.showContents )
        self.text4.pack( side = LEFT, padx = 5 )

    def showContents( self, event ):
        """ Display the contents of the Entry """

        # acquire name of Entry component that genereated event
        theName = event.widget.winfo_name()

        # acquire contents of Entry component that generated event
        theContents = event.widget.get()
        showinfo( "Message", theName + ":" + theContents)


demo = EntryDemo()

demo.mainloop()