目录
1.简介
1.1定时程序设计
1.2颜色选择程序设计
2.使用Lambda表达式
3.建立含图像的功能按钮
4.简易计算器按钮设计
5.设计鼠标光标在功能按钮上的的形状
1.简介
功能按钮也称为按钮，在窗口组件中可以设计在单击功能按钮时，执行某一个特定的动作，这个动作也称为callback方法，也就是说我们可以将功能按钮当作用户与程序沟通的桥梁。功能按钮上面可以有文字，或是和标签一样可以有图像，如果是文字样式的功能按钮，可以设定此文字的字形。它的语法格式如下：
Button(父对象, options, ……)
Button()方法的第一个参数是父对象，表示这个功能按钮将建立在哪一个窗口内。下列是Button()方法内其他常用的options参数。
| borderwidth或bd | 边界宽度默认是两个像素 |
| bg或background | 背景颜色 |
| command | 单机功能按钮时，执行此方法 |
| cursor | 当鼠标光标移至按钮上时的形状 |
| fg或foreground | 前景颜色 |
| font | 字形 |
| height | 高，单位是字符 |
| highlightbackground | 当前功能按钮取得焦点时的背景颜色 |
| highlightcolor | 当功能按钮取得焦点时的颜色 |
| image | 功能钮上的图像 |
| justify | 当有多行文字时，最后一行文字的对齐方式 |
| padx | 默认是1，可设置功能按钮与文字的间隔 |
| pady | 默认是1，可设置功能按钮的上下的间距 |
| relief | 默认是relief=FLAT，可由此控制文字外框 |
| state | 默认是state=NORMAL，若设置为DISABLED则以灰阶显示功能按钮，表示暂时无法使用 |
| text | 功能按钮名称 |
| underline | 可以设置第几个文字有下划线，从0开始算起，默认是-1表示无下划线 |
| width | 宽，单位是字符 |
| wraplength | 限制每行的文字数，默认是0，表示只有”n”才会换行 |
当单机功能按钮时可以显示字符串”Hello world”，底色是浅黄色，字符串颜色是黑色
from tkinter import *def msgShow(): label["text"] = "Hello world" label["bg"] = "lightyellow" label["fg"] = "black"root = Tk()label = Label(root) # 创建label标签btn = Button(root, text = "打印消息", command = msgShow)label.pack()btn.pack()root.mainloop()
上述程序是先建立一个不含属性的标签对象label，然后建立一个功能按钮。单机按钮时，会启动msgShow函数，然后此函数会执行标签label的内容。也可以用config()方法一次性设置所有的label属性:
label.config(text = "Hello world", bg = "lightyellow", fg = "black")
下面新增按钮功能
btn1 = Button(root, text = "结束", width = 20, command = root.destroy)
root.destroy可以关闭root窗口对象，同时结束程序。另一个常用方法是quit，可以让Python Shell内执行的程序结束，但是root窗口则继续执行。
1.1定时程序设计
from tkinter import *counter = 0 # 计数的初始值def run_counter(digit): # 数字变量内容的变动 def counting(): # 变动数字方法 global counter # 定义这是全局变量 counter += 1 digit.config(text = str(counter)) # 显示数字内容 digit.after(1000, counting) # 隔一次后调用counting counting() # 持续调用 root = Tk()digit = Label(root, bg = "lightyellow", fg = "black", height = 3, width = 10, font = "黑体 20 bold")digit.pack()run_counter(digit)btn = Button(root, text ="结束", width = 15, command = root.destroy)btn.pack()root.mainloop()
1.2颜色选择程序设计
from tkinter import *def yellow(): # 自定义颜色背景 root.config(bg = "yellow")def blue(): root.config(bg = "blue")def red(): root.config(bg = "red")root = Tk()root.geometry("500x500")yellowbtn = Button(root, text = "yellow", command = yellow)bluebtn = Button(root, text = "blue", command = blue)redbtn = Button(root, text = "red", command = red)exitbtn = Button(root, text = "Exit", command = root.destroy)yellowbtn.pack(anchor = S, side = RIGHT, padx = 10, pady = 10)bluebtn.pack(anchor = S, side = RIGHT, padx = 10, pady = 10)redbtn.pack(anchor = S, side = RIGHT, padx = 10, pady = 10)exitbtn.pack(anchor = S, side = RIGHT, padx = 10, pady = 10)root.mainloop() 2.使用Lambda表达式
在前文程序中，Yellow按钮和Blue按钮执行相同的工作，但是传递的颜色参数不同，其实这是使用Lambda表达式的好时机。我们可以通过Lambda表达式调用相同的方法，但是传递不同参数的方式简化设计
def bColor(bgColor): root.config(bg = bgColor)exitbtn = Button(root, text = "Exit", command = root.destroy)bluebtn = Button(root, text = "blue", command = lambda:bColor("blue"))yellowbtn = Button(root, text = "yellow", command = lambda:bColor("yellow"))redbtn = Button(root, text = "red", command = lambda:bColor("red")) （效果和之前是一样的）
3.建立含图像的功能按钮
一般功能按钮是用文字当作按钮名称，也可以用图像当作按钮名称。若是使用图像当作按钮，在Button()内可以省略text参数设置按钮名称，但在Button()内要增加images参数设置图像对象。
from tkinter import *def msgShow(): label.config(text = "Hello world", bg = "lightyellow", fg = "blue")root = Tk()label = Label(root)image = PhotoImage(file = "2.png")btn = Button(root, image = image, command = msgShow)label.pack()btn.pack()root.mainloop()
4.简易计算器按钮设计
from tkinter import *root = Tk()lab = Label(root, text ="", bg = "yellow", width = 20)btn7 = Button(root, text = "7", width = 3)btn8 = Button(root, text = "8", width = 3)btn9 = Button(root, text = "9", width = 3)btnc = Button(root, text = "*", width = 3)btn4 = Button(root, text = "4", width = 3)btn5 = Button(root, text = "5", width = 3)btn6 = Button(root, text = "6", width = 3)btnj = Button(root, text = "-", width = 3)btn1 = Button(root, text = "1", width = 3)btn2 = Button(root, text = "2", width = 3)btn3 = Button(root, text = "3", width = 3)btna = Button(root, text = "+", width = 3)btn0 = Button(root, text = "0", width = 8)btnd = Button(root, text = ".", width = 3)btne = Button(root, text = "=", width = 3)lab.grid(row = 0, column = 0, columnspan = 4)btn7.grid(row =1, column = 0, padx = 5)btn8.grid(row =1, column = 1, padx = 5)btn9.grid(row =1, column = 2, padx = 5)btnc.grid(row =1, column = 3, padx = 5)btn4.grid(row =2, column = 0, padx = 5)btn5.grid(row =2, column = 1, padx = 5)btn6.grid(row =2, column = 2, padx = 5)btnj.grid(row =2, column = 3, padx = 5)btn1.grid(row =3, column = 0, padx = 5)btn2.grid(row =3, column = 1, padx = 5)btn3.grid(row =3, column = 2, padx = 5)btna.grid(row =3, column = 3, padx = 5)btn0.grid(row =4, column = 0, padx = 5, columnspan = 2)btnd.grid(row =4, column = 2, padx = 5)btne.grid(row =4, column = 3, padx = 5)root.mainloop()
5.设计鼠标光标在功能按钮上的的形状
from tkinter import *def msgShow(): label.config(text = "Hello world", bg = "lightyellow", fg = "blue")root = Tk()label = Label(root)image = PhotoImage(file = "2.png")btn = Button(root, image = image, command = msgShow, cursor = "plus")label.pack()btn.pack()root.mainloop()
参考文献：《Python GUI设计tkinter菜鸟编程》洪锦魁著
