老师你好,照着代码打后,会出错,咋回事
from tkinter.filedialog import *
from tkinter.colorchooser import *
win_width = 900
win_height = 700
class Application(Frame):
    def __init__(self, master=None, bgcolor="#000000"):
        super().__init__(master)
        self.master = master
        self.bgcolor = bgcolor
        self.x = 0
        self.y = 0
        self.fgcolor = "#ff0000"
        self.lastDraw=0
        self.startDrawFlag=False
        self.pack()
        self.createWidget()
    def createWidget(self):
        self.drawpad = Canvas(root, width=win_width, height=win_height * 0.8, bg=self.bgcolor)
        self.drawpad.pack()
        # 创建按钮
        btn_start = Button(root, text="开始", name="start")
        btn_start.pack(side="left", padx="10")
        btn_pen = Button(root, text="画笔", name="pen")
        btn_pen.pack(side="left", padx="10")
        btn_rect = Button(root, text="矩形", name="rect")
        btn_rect.pack(side="left", padx="10")
        btn_clear = Button(root, text="清屏", name="clear")
        btn_clear.pack(side="left", padx="10")
        btn_erasor = Button(root, text="橡皮擦", name="erasor")
        btn_erasor.pack(side="left", padx="10")
        btn_line = Button(root, text="直线", name="line")
        btn_line.pack(side="left", padx="10")
        btn_lineArror = Button(root, text="箭头直线", name="lineArror")
        btn_lineArror.pack(side="left", padx="10")
        btn_color = Button(root, text="颜色", name="color")
        btn_color.pack(side="left", padx="10")
        btn_pen.bind_class("Button", "<1>", self.eventManager)
        self.drawpad.bind("<ButtonRelease-1>",self.stopDraw)
#添加颜色切换的快捷键
        #btn_pen.bind_class("Button","<1>",self.eventManager)
        #self.drawpad.bind("<ButtonRelease-1>",self.stopDraw)
        root.bind("<KeyPress-r>",self.kuanjiejian)
        root.bind("KeyPress-g>",self.kuaijiejian)
        root.bind("KeyPress-y",self.kuaijiejian)
    def eventManager(self, event):
        name = event.widget.winfo_name()
        print(name)
        if name == "line":
            self.drawpad.bind("<B1-Motion>", self.myline)
        elif name=="lineArrow":
            self.drawpad.bind("<B1-Motion>", self.mylineArrow)
        elif name == "rect":
            self.drawpad.bind("<B1-Motion>", self.myRect)
        elif name == "pen":
            self.drawpad.bind("<B1-Motion>", self.myPen)
        elif name == "erasor":
            self.drawpad.bind("<B1-Motion>", self.myErasor)
        elif name=="clear":
            self.drawpad.delete("all")
        elif name=="color":
            c=askcolor(color=self.fgcolor,totle="选择画笔颜色")
            self.fgcolor=c[1]
    def stopDraw(self,event):
        self.startDrawFlag=False
        self.lastDraw=0
    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 myline(self, event):
        self.startDraw(event)
        self.lastDraw=self.drawpad.create_line(self.x, self.y, event.x, event.y, fill=self.fgcolor)
    def mylineArrow(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 myRect(self,event):
        self.startDraw(event)
        self.drawpad.create_rectangle(self.x, self.y, event.x, event.y, outline=self.fgcolor)
    def myPen(self,event):
        self.startDraw(event)
        self.drawpad.create_line(self.x, self.y, event.x, event.y, fill=self.fgcolor)
        self.x=event.x
        self.y=event.y
    def myErasor(self,event):
        self.startDraw(event)
        self.drawpad.create_rectangle(event.x-4, event.y-4, event.x+4, event.y+4, fill=self.bgcolor)
        self.x=event.x
        self.y=event.y
    def kuaijiejian(self, event):
        if event.char == "r":
            self.fgcolor = "#ff0000"
        elif event.char == "g":
                self.fgcolor = "#00ff00"
        elif event.char == "y":
                self.fgcolor = "#ffff00"
if __name__ == '__main__':
    root = Tk()
    root.geometry(str(win_width) + "x" + str(win_height) + "+200+300")
    root.title("百战程序员的画图软件")
    app = Application(master=root)
    root.mainloop()