tkinter 界面设计 — 画板

标题 tkinter 界面设计 — 画板

上一次写文章还是7.18号了，到现在快20天没有更新了。也不是因为懒，我学习python的时间并不是很多。只有每天早上或者晚上下班回家才有时间。从上次更新到今天。这20天的时间里，学习了新的内容。就是 tkinter 界面设计。这里对 tkinter 就不过多介绍。先记录一下我学习的第一个软件 —— 画板
首先看一下界面效果。

代码实现

导入需要的模块

from tkinter import *
import tkinter as tk
from tkinter.simpledialog import *
from tkinter.colorchooser import *

采用面向对象的方式，分步实现每个控件的功能。
1、设计主窗口界面

if __name__ == '__main__':
    mywindow = Tk()
    win_width = 900
    win_height = 500
    mywindow.geometry(str(win_width) + "x" + str(win_height + 50) + "+200+300")
    mywindow.title('画板')
    app = DrawApp(master=mywindow)
    mywindow.mainloop()

geometry的代码格式是 geometry(“axb+c+d”) 其中“x” 是字母 x
2、创建类，继承 Frame 模块

class DrawApp(Frame):
    """开发画图软件"""

    def __init__(self, master=None, bgcolor="white"):
        super().__init__(master)  # super 父类方法调用
        self.master = master
        #  self.v = StringVar(mywindow)  用于存储变量，方便后面获取笔号，画出不同粗细的图画
        self.v = StringVar(mywindow)
        #  设置背景颜色，背景色为白色
        self.bgcolor = bgcolor
        #  设置xy 的初始值
        self.x = 0
        self.y = 0
        # 设置默认前景色，也就是画笔的颜色
        self.fgcolor = "red"
        self.lastDraw = 0
        self.startDrawFlag = False
        self.pack()
        self.creatwidget()

3、 创建画布，并且依次排列各个组件

 def creatwidget(self):
        """创建新的组件"""
        # 创建一个绘图区域
        self.drawpad = Canvas(mywindow, width=win_width, height=win_height, bg=self.bgcolor)
        self.drawpad.pack()
        # 创建按钮
        btn_start = Button(mywindow, text="开始", width=10, name="start")
        btn_start.pack(side="left")
        #  这里创建一个多选菜单，可供选择不同粗细的笔号
        #  设置变量，存储笔号，方便后面判断不同的笔号，响应不同的程序，做出不同的输出
        self.v.set("笔号")
        btn_pen1 = OptionMenu(mywindow, self.v, "1号笔", "2号笔", "3号笔")
        btn_pen1.pack(side="left")
        btn_rect = Button(mywindow, text="矩形", width=10, name="rect")
        btn_rect.pack(side="left")
        btn_clear = Button(mywindow, text="清屏", width=10, name="clear")
        btn_clear.pack(side="left")
        btn_erasor = Button(mywindow, text="橡皮檫", width=10, name="erasor")
        btn_erasor.pack(side="left")
        btn_line = Button(mywindow, text="直线", width=10, name="line")
        btn_line.pack(side="left")
        btn_lineArrow = Button(mywindow, text="箭头直线", width=10, name="lineArrow")
        btn_lineArrow.pack(side="left")
        btn_color = Button(mywindow, text="颜色", width=10, name="color")
        btn_color.pack(side="left")
        btn_oval = Button(mywindow, text="椭圆", width=10, name="oval")
        btn_oval.pack(side="left")
        btn_Text = Button(mywindow, text="画笔", width=10, name="pen2")
        btn_Text.pack(side="left")
        # 事件处理
        #  bind_class,它接受三个参数，第一个参数是类名，第二个参数是事件类型，第三个参数是相应的操作
        btn_pen1.bind_class("Button", "", self.eventManager)
        self.drawpad.bind("", self.stopDraw)

4、分别处理不同的事件

    def eventManager(self, event):
    #  获取事件名字，根据事件名字判断操作类型
        name = event.widget.winfo_name()
        if name == "line":
        #  在画图之前，必须要选择笔号才能够开始，    self.message() 用来提示
        #  用bind 函数绑定不同的事件
            self.message（）
            self.drawpad.bind("", self.myLine)
        elif name == "lineArrow":
            self.message()
            self.drawpad.bind("", self.myLineArrow)
        elif name == "rect":
            self.message()
            self.drawpad.bind("", self.myRect)
        elif name == "pen2":
            self.message()
            self.drawpad.bind("", self.myPen)
        elif name == "oval":
            self.message()
            self.drawpad.bind("", self.myOval)
        elif name == "erasor":
            self.message()
            self.drawpad.bind("", self.myErasor)
        elif name == "clear":
            self.drawpad.delete("all")
        elif name == "color":
            c = askcolor(color=self.fgcolor, title="选择画笔颜色")
            self.fgcolor = c[1]
        elif name == "text":
            self.drawpad.bind("", self.myText)

5、写出对应事件的函数

#  增加一个判断
    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

5.1 画直线

    def myLine(self, event):
        if self.v.get() == "1号笔":
            self.startDraw(event)   #  这个设置使得每次画线不会重复出现
            
            self.lastDraw = self.drawpad.create_line(self.x, self.y, event.x, event.y,
                                                     fill=self.fgcolor, width=1)
        if self.v.get() == "2号笔":
            self.startDraw(event)
            self.lastDraw = self.drawpad.create_line(self.x, self.y, event.x, event.y,
                                                     fill=self.fgcolor, width=3)
        if self.v.get() == "3号笔":
            self.startDraw(event)
            self.lastDraw = self.drawpad.create_line(self.x, self.y, event.x, event.y,
                                                     fill=self.fgcolor, width=5)

5.2、画带箭头的直线

 def myLineArrow(self, event):
        if self.v.get() == "1号笔":
            self.startDraw(event)
            self.lastDraw = self.drawpad.create_line(self.x, self.y, event.x, event.y, arrow=LAST,
                                                     fill=self.fgcolor, width=1)
        if self.v.get() == "2号笔":
            self.startDraw(event)
            self.lastDraw = self.drawpad.create_line(self.x, self.y, event.x, event.y, arrow=LAST,
                                                     fill=self.fgcolor, width=3)
        if self.v.get() == "3号笔":
            self.startDraw(event)
            self.lastDraw = self.drawpad.create_line(self.x, self.y, event.x, event.y, arrow=LAST,
                                                     fill=self.fgcolor, width=5)

5.3、画矩形

	 def myRect(self, event):
        if self.v.get() == "1号笔":
            self.startDraw(event)
            self.lastDraw = self.drawpad.create_rectangle(self.x, self.y, event.x, event.y,
                                                          outline=self.fgcolor, width=1)
        if self.v.get() == "2号笔":
            self.startDraw(event)
            self.lastDraw = self.drawpad.create_rectangle(self.x, self.y, event.x, event.y,
                                  outline=self.fgcolor, width=3)
        if self.v.get() == "3号笔":
            self.startDraw(event)
            self.lastDraw = self.drawpad.create_rectangle(self.x, self.y, event.x, event.y,
                                  outline=self.fgcolor, width=5)

5.4、画椭圆

    def myOval(self, event):
        if self.v.get() == "1号笔":
            self.startDraw(event)
            self.lastDraw = self.drawpad.create_oval(self.x, self.y, event.x, event.y,
                                                          outline=self.fgcolor, width=1)

        if self.v.get() == "2号笔":
            self.startDraw(event)
            self.lastDraw = self.drawpad.create_oval(self.x, self.y, event.x, event.y,
                                       outline=self.fgcolor, width=3)
        if self.v.get() == "3号笔":
            self.startDraw(event)
            self.lastDraw = self.drawpad.create_oval(self.x, self.y, event.x, event.y,
                                       outline=self.fgcolor, width=5)

5.5、自由画笔

    def myPen(self, event):
        if self.v.get() == "1号笔":
            self.startDraw(event)
            self.drawpad.create_line(self.x, self.y, event.x, event.y,
                                     fill=self.fgcolor, width=1)
            self.x = event.x
            self.y = event.y
        if self.v.get() == "2号笔":
            self.startDraw(event)
            self.drawpad.create_line(self.x, self.y, event.x, event.y,
                                     fill=self.fgcolor, width=3)
            self.x = event.x
            self.y = event.y
        if self.v.get() == "3号笔":
            self.startDraw(event)
            self.drawpad.create_line(self.x, self.y, event.x, event.y,
                                     fill=self.fgcolor, width=5)
            self.x = event.x
            self.y = event.y

5.6、橡皮檫

    def myErasor(self, event):
        if self.v.get() == "1号笔":
            self.startDraw(event)
            self.drawpad.create_rectangle(event.x-3, event.y-3, event.x, event.y,
                                          outline=self.bgcolor,
                                     fill=self.bgcolor)
            self.x = event.x
            self.y = event.y
        if self.v.get() == "2号笔":
            self.startDraw(event)
            self.drawpad.create_rectangle(event.x-8, event.y-8, event.x, event.y,
                                          outline=self.bgcolor,
                                     fill=self.bgcolor)
            self.x = event.x
            self.y = event.y
        if self.v.get() == "3号笔":
            self.startDraw(event)
            self.drawpad.create_rectangle(event.x-20, event.y-20, event.x, event.y,
                                          outline=self.bgcolor,
                                     fill=self.bgcolor)
            self.x = event.x
            self.y = event.y

5.7、提示信息，如果没有选择画笔，则无法开始

 def message(self):
        if self.v.get() == "笔号":
            messagebox.showwarning("未选择笔号", "请先选择笔号")

到此，整个程序就写完了。这个程序是根据老师的课程，做了稍微的改动。关于各个画笔的控件函数，需要好好的琢磨琢磨，这个可能不是很容易理解的。学习就是不断发现问题解决问题的过程中。逆水行舟，只有坚持才能前行。