【Python基础】1.4.4 图形用户实例——用Python实现简易聊天对话框

1. 界面设计
   Step1：界面布局设计
   Step2：创建所需控件
   Step3：设定事件与命令响应
   Step4：对控件进行布局
   Step5：完成程序代码

2. 命名规则
   原则：统一；控件+功能
   例：frmLT->fram+LeftTop
   txtMsg->text+Message
   btnSend->buttom+Send

3. 一个简易聊天界面——基于Tk库

from tkinter import *import timedef main():  def sendMsg():#发送消息    strMsg = '我:' + time.strftime("%Y-%m-%d %H:%M:%S",                                  time.localtime()) + '\n '    txtMsgList.insert(END, strMsg, 'greencolor')    txtMsgList.insert(END, txtMsg.get('0.0', END))    txtMsg.delete('0.0', END)  def cancelMsg():#取消消息    txtMsg.delete('0.0', END)  def sendMsgEvent(event): #发送消息事件    if event.keysym == "Up":      sendMsg()  #创建窗口   t = Tk()  t.title('与python聊天中')  #创建frame容器(宽度，高度，背景)  frmLT = Frame(width=500, height=320, bg='white')  frmLC = Frame(width=500, height=150, bg='white')  frmLB = Frame(width=500, height=30)  frmRT = Frame(width=200, height=500)  #创建控件  txtMsgList = Text(frmLT)  txtMsgList.tag_config('greencolor', foreground='#008C00')#创建tag  txtMsg = Text(frmLC);  #发送消息事件  txtMsg.bind("<KeyPress-Up>", sendMsgEvent)  btnSend = Button(frmLB, text='发送', width = 8, command=sendMsg)  btnCancel = Button(frmLB, text='取消', width = 8, command=cancelMsg)  imgInfo = PhotoImage(file = "python.gif")  lblImage = Label(frmRT, image = imgInfo)  lblImage.image = imgInfo  #窗口布局(span为跨越数，LT中columnspan(2)意为LT跨越两列，padx/pady意为分割比例为1/3)  frmLT.grid(row=0, column=0, columnspan=2, padx=1, pady=3)  frmLC.grid(row=1, column=0, columnspan=2, padx=1, pady=3)  frmLB.grid(row=2, column=0, columnspan=2)  frmRT.grid(row=0, column=2, rowspan=3, padx=2, pady=3)  #固定大小  frmLT.grid_propagate(0)  frmLC.grid_propagate(0)  frmLB.grid_propagate(0)  frmRT.grid_propagate(0)  #第3行第1列插入按钮Send  btnSend.grid(row=2, column=0)  btnCancel.grid(row=2, column=1)  lblImage.grid()  txtMsgList.grid()  txtMsg.grid()  #主事件循环  t.mainloop()if __name__ == '__main__':    main()