十二、GUI设计-画图程序

"""小小画笔"""

from tkinter import *
from tkinter.filedialog import *
from tkinter.colorchooser import *

height_root = 450
width_root = 900
class Application(Frame):
    def __init__(self, master=None,bgcolors="#000000"):
        super().__init__(master)        # super()代表的是父类的定义，而不是父类对象
        self.master = master
        self.bgcolors = bgcolors
        self.pack()
        self.createWidget()
        self.x = 0
        self.y = 0
        self.fgcolor = "#ff0000"
        self.lastdrawLine = 0
        self.drawFlag = FALSE
    def createWidget(self):
        #创建画图区域
        self.drawPad = Canvas(root, width=width_root, height=height_root*0.9, bg=self.bgcolors)
        self.drawPad.pack()

        #创建按钮
        btn_start = Button(text="开始", name="start")
        btn_start.pack(side="left",padx=10)
        btn_pen = Button(text="画笔", name="pen")
        btn_pen.pack(side="left", padx=10)
        btn_rect = Button(text="矩形", name="rect")
        btn_rect.pack(side="left", padx=10)
        btn_clear = Button(text="清屏", name="clear")
        btn_clear.pack(side="left", padx=10)
        btn_earsor = Button(text="橡皮差", name="earsor")
        btn_earsor.pack(side="left", padx=10)
        btn_line = Button(text="直线", name="line")
        btn_line.pack(side="left", padx=10)
        btn_lineArrow = Button(text="箭头直线", name="lineArrow")
        btn_lineArrow.pack(side="left", padx=10)
        btn_color = Button(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.drawFlagRelease)

    def eventManager(self,event):
        name = event.widget.winfo_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 == "earsor":
            self.drawPad.bind("<B1-Motion>", self.myearsor)
        elif name == "clear":
            self.drawPad.delete("all")
        elif name == "color":
            colorpen = askcolor(color="red", title="请选择画笔颜色")
            self.fgcolor = colorpen[1]

    def drawFlagRelease(self,event):
        self.drawFlag = FALSE
        self.lastdrawLine = 0

    def drawStartMove(self,event):
        self.drawPad.delete(self.lastdrawLine)
        if not self.drawFlag:
            self.drawFlag = True
            self.x = event.x
            self.y = event.y

    def myline(self, event):
        self.drawStartMove(event)
        self.lastdrawLine = self.drawPad.create_line(self.x, self.y, event.x, event.y, fill=self.fgcolor)

    def mypen(self, event):
        self.drawStartMove(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 myearsor(self, event):
        self.drawStartMove(event)
        self.drawPad.create_rectangle(event.x-4, event.y-4, event.x+4, event.y+4, fill=self.bgcolors)

    def mylineArrow(self,event):
        self.drawStartMove(event)
        self.lastdrawLine = self.drawPad.create_line(self.x, self.y, event.x,event.y, arrow=LAST, fill=self.fgcolor)

    def myrect(self, event):
        self.drawStartMove(event)
        self.lastdrawLine = self.drawPad.create_rectangle(self.x, self.y, event.x, event.y,  outline=self.fgcolor)

if __name__ == '__main__':
    root = Tk()
    root.geometry(str(width_root)+"x"+str(height_root)+"+200+300")
    root.title("党京伟的一个画笔软件")
    app = Application(master=root)
    root.mainloop()