Python GUI 03----Button

from tkinter import *
#定义Button的回调函数
def helloButton():
    print ('hello button')
root = Tk()
#通过command属性来指定Button的回调函数
Button(root,text = 'Hello Button',command = helloButton).pack()
root.mainloop()

from tkinter import *
root = Tk()
#flat, groove, raised, ridge, solid, or sunken
Button(root,text = 'hello button',relief=FLAT).pack()
Button(root,text = 'hello button',relief=GROOVE).pack()
Button(root,text = 'hello button',relief=RAISED).pack()
Button(root,text = 'hello button',relief=RIDGE).pack()
Button(root,text = 'hello button',relief=SOLID).pack()
Button(root,text = 'hello button',relief=SUNKEN).pack()

root.mainloop()

3.与Label一样，Button也可以同时显示文本与图像，使用属性compound

from tkinter import *
root = Tk()
#图像居下,居上，居右，居左，文字位于图像之上
Button(root,text = 'botton',compound = 'bottom',bitmap = 'error').pack()
Button(root,text = 'top',compound = 'top',bitmap = 'error').pack()
Button(root,text = 'right',compound = 'right',bitmap = 'error').pack()
Button(root,text = 'left',compound = 'left',bitmap = 'error').pack()
Button(root,text = 'center',compound = 'center',bitmap = 'error').pack()

root.mainloop()

4.控件焦点问题

from tkinter import *

def cb1():
    print ('button1 clicked')
def cb2(event):
    print ('button2 clicked')
def cb3():
    print ('button3 clicked')
    
root = Tk()

b1 = Button(root,text = 'Button1',command = cb1)
b2 = Button(root,text = 'Button2')
b2.bind("<Return>",cb2)                            #Return事件相应回车点击。Enter事件响应的是mouseover
b3 = Button(root,text = 'Button3',command = cb3)
b1.pack()
b2.pack()
b3.pack()

b2.focus_set()                                     #将焦点定在按钮b2上
root.mainloop()

5.指定Button的宽度与高度

from tkinter import *
root = Tk()
b1 = Button(root,text = '30X1',width = 30,height = 2)
b1.pack()

b2 = Button(root,text = '30X2')
b2['width'] = 30
b2['height'] = 3
b2.pack()

b3 = Button(root,text = '30X3')
b3.configure(width = 30,height = 3)
b3.pack()

root.mainloop()

6.设置Button文本在控件上的显示位置

from Tkinter import *
root = Tk()

#简单就是美！
for a in ['n','s','e','w','ne','nw','se','sw']:
    Button(root,
    text = 'anchor',
    anchor = a,
    width = 30,
    height = 4).pack()

7.改变Button的前景色与背景色

from tkinter import *
root = Tk()
bfg = Button(root,text = 'change foreground',fg = 'red')
bfg.pack()

bbg = Button(root,text = 'change backgroud',bg = 'blue')
bbg.pack()

root.mainloop()

# 创建5个Button边框宽度依次为：0，2，4，6，8
from tkinter import *
root = Tk()
for b in [0,1,2,3,4]:
    Button(root,
    text = str(b),
    bd = b).pack()
root.mainloop()    

9.设置Button状态

from tkinter import *
root = Tk()
def statePrint():
    print ('state')
for r in ['normal','active','disabled']:
    Button(root,
    text = r,
    state = r,
    width = 30,
    command = statePrint).pack()
root.mainloop()

例子中将三个Button在回调函数都设置为statePrint,运行程序只有normal和active激活了回调函数，而disable按钮则没有，对于暂时不需要按钮起作用时，可以将它的state设置为disabled属性

10.绑定Button与变量设置Button在textvariable属性

from tkinter import *
root = Tk()
def changeText():
    if b['text'] == 'text':
        v.set('change')
    else:
        v.set('text')
v = StringVar()
b = Button(root,textvariable = v,command = changeText)
v.set('text')
b.pack()
root.mainloop()