Question

我正在尝试使用PIL为我的Tkinter添加一点天赋，但是我遇到一个问题，即PIL的混合功能似乎不正确地淡入第二张图像（example）。（PS，Squirtle最好）

我尝试根据发现的here in a similar question答案对代码进行建模，但是产生的淡入效果并不完全正确。

以下是针对此问题的程序代码段：

try:
    import Tkinter as tk
except ImportError:
    import tkinter as tk
from PIL import Image, ImageTk
import os

def RGBAImage(path):
    return Image.open(path).convert("RGBA")

class MainApp(tk.Tk):
    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)
        app = App(parent=self, controller=self)
        app.grid(row=0, column=0)

class App(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller

        self.alpha = 0

        # combine the base image and the border frame using paste
        self.img_pieces = []
        for i in range(2, 5):
            self.img_pieces.append(RGBAImage("media\\piltest%d.png" %(i)))
        self.img_border = RGBAImage("media\\piltest1.png")
        for i in range(3):
            self.img_pieces[i].paste(self.img_border, (0, 0), self.img_border)

        # use ImageTk to create PhotoImage for Tkinter
        self.images = []
        for i in range(3):
            self.images.append(ImageTk.PhotoImage(self.img_pieces[i]))

        # establish example images
        self.examples = []
        for i in range(3):
            self.examples.append(tk.Label(self, image=self.images[i]))
            self.examples[i].image = self.images[i]
            self.examples[i].grid(row=0, column=i, sticky="nsew")

        # create "fading" images example
        self.button = tk.Button(self, image=self.images[0], command=lambda:self.fade())
        self.button.image = self.images[0]
        self.button.grid(row=0, column=3, sticky="nsew")

    def fade(self):
        # stop fading once alpha == 1 (a.k.a. second image)
        if self.alpha == 1.0:
            return

        # create the interpolated image using the current alpha value
        self.new_img = ImageTk.PhotoImage(Image.blend(self.img_pieces[0], self.img_pieces[2], self.alpha))
        self.alpha = self.alpha + 0.1

        # update the image displayed continuously to create the "fade" effect
        self.button.config(image=self.new_img)
        self.button.image = self.new_img
        self.after(10, self.fade)

if __name__ == "__main__":
    os.chdir(os.path.dirname(os.path.abspath(__file__)))
    app = MainApp()
    app.mainloop()

感谢您的帮助！

Answer 1

问题在于退出条件：

if self.alpha == 1.0:
    return

在进一步检查后循环中alpha的变化时，alpha超过了1.0并一直无限运行，因此应将代码更改为以下内容以正确地停止在1.0：

if self.alpha > 1.0:
    return

两个图像之间的淡入淡出（PIL / Tkinter）

1 个答案: