python基于tkinter写的画图项目分析

# coding=utf-8
from tkinter import *
from tkinter.filedialog import *
from tkinter.colorchooser import *
win_width=900   #定义全局变量
win_height=450  #定义全局变量
class AppLication(Frame):
    #初始化区
    def __init__(self,master=None,bg="#000000"):
        super().__init__(master)
        self.master=master
        self.x=0
        self.y=0
        self.pack()
        self.bg=bg
        self.fgcolor="#ff0000"
        self.lastdraw=0
        self.startdrawflag=False
        self.CreateWidget()
    #创建控件
    def CreateWidget(self):
        #创建画布
        self.drawpad=Canvas(root,bg=self.bg,width=win_width,height=win_height)
        self.drawpad.pack()
        #创建按钮
        btnstart=Button(root,text="开始",name='start')
        btnstart.pack(side="left",padx=10)
        btnpen=Button(root,text="画笔",name='pen')
        btnpen.pack(side="left",padx=10)
        btnrect=Button(root,text="画矩形",name='rect')
        btnrect.pack(side="left",padx=10)
        btnclear=Button(root,text="清屏",name='clear')
        btnclear.pack(side="left",padx=10)
        btneraser=Button(root,text="橡皮擦",name='eraser')
        btneraser.pack(side="left",padx=10)
        btnline=Button(root,text="直线",name='line')
        btnline.pack(side="left",padx=10)
        btnlineraw=Button(root,text="直线(箭头)",name='lineraw')
        btnlineraw.pack(side="left",padx=10)
        btncolor=Button(root,text="颜色",name='color')
        btncolor.pack(side="left",padx=10)
        #绑定事件处理
        btnpen.bind_class("Button","<1>",self.eventManager)
        self.drawpad.bind("<ButtonRelease-1>",self.stopDraw)
        #绑定键盘快捷键
        root.bind("<KeyPress-g>",self.kuaijiejian)
        root.bind("<KeyPress-b>",self.kuaijiejian)
    def eventManager(self,event):
        name=event.widget.winfo_name()
        print(name)
        if name=='line':
            self.drawpad.bind("<B1-Motion>",self.linecreate)
        elif name=='lineraw':
            self.drawpad.bind("<B1-Motion>",self.lineArrow)
        elif name=="rect":
            self.drawpad.bind("<B1-Motion>",self.rect)
        elif name=="pen":
            self.drawpad.bind("<B1-Motion>",self.pen)
        elif name=='eraser':
            self.drawpad.bind("<B1-Motion>",self.eraser)
        elif name=='clear':
            self.drawpad.delete("all")
        elif name=='color':
            s1=askcolor(title="选择颜色",color=self.fgcolor)
            self.fgcolor=s1[1]
    def startDraw(self,event):
        self.drawpad.delete(self.lastdraw)
        if not self.startdrawflag:
            self.startdrawflag=True
            self.x=event.x
            self.y=event.y
    def stopDraw(self,event):
        self.startdrawflag=False
        self.lastdraw=0
    def linecreate(self,event):
        self.startDraw(event)
        self.lastdraw=self.drawpad.create_line(self.x,self.y,event.x,event.y,fill=self.fgcolor)
    def lineArrow(self,event):
        self.startDraw(event)
        self.lastdraw=self.drawpad.create_line(self.x,self.y,event.x,event.y,arrow=LAST,fill=self.fgcolor)
    def rect(self,event):
        self.startDraw(event)
        self.lastdraw=self.drawpad.create_rectangle(self.x,self.y,event.x,event.y,outline=self.fgcolor)
    def pen(self,event):
        self.startDraw(event)
        self.lastdraw=self.drawpad.create_line(self.x,self.y,event.x,event.y,fill=self.fgcolor)
        self.x=event.x
        self.y=event.y
    def eraser(self,event):
        self.startDraw(event)
        self.drawpad.create_rectangle(self.x-4,self.y-4,event.x+4,event.y+4,fill=self.bg)
        self.x=event.x
        self.y=event.y
    def kuaijiejian(self,event):
        #设置按钮快捷键
#运行区
if __name__=='__main__':
    root=Tk()
    root.geometry(str(win_width)+"x"+str(win_height+100)+"+100+100")
    root.title("画图软件")
    app=AppLication(master=root)
    root.mainloop()