Rounded button tkinter python

问题

I am trying to get rounded buttons for my script using tkinter.

I found the following code:

from tkinter import *
import tkinter as tk

class CustomButton(tk.Canvas):
    def __init__(self, parent, width, height, color, command=None):
        tk.Canvas.__init__(self, parent, borderwidth=1, 
            relief="raised", highlightthickness=0)
        self.command = command

        padding = 4
        id = self.create_oval((padding,padding,
            width+padding, height+padding), outline=color, fill=color)
        (x0,y0,x1,y1)  = self.bbox("all")
        width = (x1-x0) + padding
        height = (y1-y0) + padding
        self.configure(width=width, height=height)
        self.bind("<ButtonPress-1>", self._on_press)
        self.bind("<ButtonRelease-1>", self._on_release)

    def _on_press(self, event):
        self.configure(relief="sunken")

    def _on_release(self, event):
        self.configure(relief="raised")
        if self.command is not None:
            self.command()
app = CustomButton()
app.mainloop()

but I get the following error:

TypeError: __init__() missing 4 required positional arguments: 'parent', 'width', 'height', and 'color'

回答1:

A very easy way to make a rounded button in tkinter is to use an image.

First create an image of what you want you button to look like save it as a .png and remove the outside background so it is rounded like the one below:

Next insert the image in a button with PhotoImage like this:

self.loadimage = tk.PhotoImage(file="rounded_button.png")
self.roundedbutton = tk.Button(self, image=self.loadimage)
self.roundedbutton["bg"] = "white"
self.roundedbutton["border"] = "0"
self.roundedbutton.pack(side="top")

Ensure to use border="0" and the button border will be removed.

I added the self.roundedborder["bg"] = "white" so that the the background the background of the button is the same as the Tkinter window.

The great part is that you can use any shape you like not just the normal button shapes.

回答2:

You need to create root window first (or some other widget) and give it to your CustomButton together with different parameters (see definition of __init__ method).

Try instead of app = CustomButton() the following:

app = tk.Tk()
button = CustomButton(app, 100, 25, 'red')
button.pack()
app.mainloop()

回答3:

You are not passing any arguments to the constructor.

Precisely, in this line

app = CustomButton()

you need to pass the arguments that were defined in the constructor definition, namely the parent, width, height and color.

回答4:

I made this rounded rectangle button if anyone was looking for more of an apple look or something. For convenience here are the arguments:

RoundedButton(parent, width, height, cornerradius, padding, fillcolor, background, command)

Note: If the corner radius is greater than half of the width or height an error message will be sent in the terminal. Pill shapes can still be made through if you set the corner radius to exactly half of the height or width.

Finally the code:

from tkinter import *
import tkinter as tk

root = Tk()

class RoundedButton(tk.Canvas):
    def __init__(self, parent, width, height, cornerradius, padding, color, bg, command=None):
        tk.Canvas.__init__(self, parent, borderwidth=0, 
            relief="flat", highlightthickness=0, bg=bg)
        self.command = command

        if cornerradius > 0.5*width:
            print("Error: cornerradius is greater than width.")
            return None

        if cornerradius > 0.5*height:
            print("Error: cornerradius is greater than height.")
            return None

        rad = 2*cornerradius
        def shape():
            self.create_polygon((padding,height-cornerradius-padding,padding,cornerradius+padding,padding+cornerradius,padding,width-padding-cornerradius,padding,width-padding,cornerradius+padding,width-padding,height-cornerradius-padding,width-padding-cornerradius,height-padding,padding+cornerradius,height-padding), fill=color, outline=color)
            self.create_arc((padding,padding+rad,padding+rad,padding), start=90, extent=90, fill=color, outline=color)
            self.create_arc((width-padding-rad,padding,width-padding,padding+rad), start=0, extent=90, fill=color, outline=color)
            self.create_arc((width-padding,height-rad-padding,width-padding-rad,height-padding), start=270, extent=90, fill=color, outline=color)
            self.create_arc((padding,height-padding-rad,padding+rad,height-padding), start=180, extent=90, fill=color, outline=color)


        id = shape()
        (x0,y0,x1,y1)  = self.bbox("all")
        width = (x1-x0)
        height = (y1-y0)
        self.configure(width=width, height=height)
        self.bind("<ButtonPress-1>", self._on_press)
        self.bind("<ButtonRelease-1>", self._on_release)

    def _on_press(self, event):
        self.configure(relief="sunken")

    def _on_release(self, event):
        self.configure(relief="raised")
        if self.command is not None:
            self.command()

def test():
    print("Hello")

canvas = Canvas(root, height=300, width=500)
canvas.pack()

button = RoundedButton(root, 200, 100, 50, 2, 'red', 'white', command=test)
button.place(relx=.1, rely=.1)

root.mainloop()

来源：https://stackoverflow.com/questions/42579927/rounded-button-tkinter-python