老师你好,按照代码打后,画不出直线是怎么回事
"""开发画图软件的菜单
"""
from tkinter.filedialog import *
from tkinter.colorchooser import *
#窗口的宽度和高度
win_width=900
win_height=450
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.pack()
        self.createWidget()
    def createWidget(self):
        drawpad= Canvas(root,width=win_width,height=win_height*0.8,bg=self.bgcolor)
        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_lineArrow = Button(root, text="箭头直线", name="lineArrow")
        btn_lineArrow.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)
    def eventManager(self,event):
        name = event.widget.winfo_name()
        print(name)
        if name=="line":
            self.drawpad.bind("B1-Motion>".self.myline)
    def myline(self,event):
        self.drawpad.create_line(self.x,self.y,event.x,event.y,fill=self.fgcolor)
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()图片如下
