在 tkinter 中调整大小和重绘 Canvas
Resizing and Redrawing Canvas in tkinter
我目前正在尝试在 canvas 上显示图像。更具体地说，我想让 canvas 上绘制的图像根据 window 的大小调整大小（这样图像总是适合 canvas).
我从一个填满整个屏幕的简单 canvas 开始。
import tkinter as tk
from PIL import Image, ImageTk
root = tk.Tk()
WIDTH, HEIGHT = root.winfo_screenwidth(), root.winfo_screenheight()
root.geometry('%dx%d+0+0' % (WIDTH, HEIGHT))
canvas = tk.Canvas(root)
canvas.pack(fill="both", expand=True)
然后我会设置我的背景图片和可以在背景上调整大小的图片。
backgroundImage = ImageTk.PhotoImage(Image.open("filepath"))
image1 = Image.open("filepath")
image2 = ...
....
....
然后我创建了一个调整图像大小的方法。
"""
This method resizes a image so that all the images fits on the GUI. This first creates an Image object,
but since the Image object does not allow access to the width and height of the Image object, a ImageTk
object needs to be created from the Image object. The ImageTk object cannot resize, but the Image object
can. So using ImageTk object to get the height and width and the Image object to resize, a new Image object
that is resized to fit the GUI is created.
@imageFile- the image file that is being resized
@windowMeasure- the measurement of the window to proportionally resize the image
@useHeight- determine the measurement being proportioned
"""
def resizedImageTk(image, windowMeasure, useHeight):
imageTk = ImageTk.PhotoImage(image)
area = windowMeasure * 4/5
tileSize = area / 4
if useHeight:
proportion = tileSize / imageTk.height()
else:
proportion = tileSize / imageTk.width()
resizedImage = image.resize((int(imageTk.width()*proportion), int(imageTk.height()*proportion)))
resizedImageTk = ImageTk.PhotoImage(resizedImage)
return resizedImageTk
然后我使用一种方法在 window 的大小发生变化时重新绘制调整大小的图像并将其绑定到根。注意：我知道这可能需要大量计算，所以我减少了这种情况发生的次数
numResizes = 0
def handle_configure(event):
if numResizes % 5 == 0:
geometry = root.geometry()
width = int(geometry[0:geometry.index("x")])
height = int(geometry[geometry.index("x")+1:geometry.index("+")])
canvas.create_image((0,0), image=backgroundImageTk, anchor="nw")
if height < width:
measurement = height
else:
measurement = width
resizedImage1 = resizedImageTk(image1, measurement, height < width)
resizedImage2 = ....
....
....
images = [resizedImage1, resizedImage2, ...]
imageWidth = resizedImage1.width()
imageHeight = resizedImage1.height()
i = 0
for row in range(0, int(len(images) / 4)):
for column in range(0, int(len(images) / 5):
x = imageWidth*column + int(width/2) - imageWidth * 2
y = imageHeight*row + int(height/2) - int(imageHeight*2.5)
canvas.create_image((x, y), image=images[i])
i=i+1
numResizes = numResizes + 1
root.bind("<Configure>", handle_configure)
root.mainloop()
我的图像中有 运行 这个，并且取得了一些成功，但是，它并不完全有效。我显示了我的背景图像，但没有显示其他图像。我不知道为什么，因为当我在嵌套的 for 循环（图像未显示）中对 canvas 使用 create_line 函数时，我确实得到了显示的行。
如果有人能对此提出一些建议，我将不胜感激！
谢谢
更新：
这是我正在尝试做的一个简单示例。您可以使用任何示例图像来测试它。
import tkinter as tk
from PIL import Image, ImageTk
root = tk.Tk()
WIDTH, HEIGHT = int(root.winfo_screenwidth() * 103/104), int(root.winfo_screenheight() * 11/12)
root.geometry('%dx%d+0+0' % (WIDTH, HEIGHT))
canvas = tk.Canvas(root)
canvas.pack(fill="both", expand=True)
testImage = Image.open("enter file path here!")
testImageTk = ImageTk.PhotoImage(testImage)
resizedTestImage = None
resizedTestImageTk = None
def handle_configure(event):
geometry = root.geometry()
width = int(geometry[0:geometry.index("x")])
height = int(geometry[geometry.index("x")+1:geometry.index("+")])
useHeight = height < width
if useHeight:
measurement = height
else:
measurement = width
if useHeight:
proportion = measurement / testImageTk.height()
else:
proportion = measurement / testImageTk.width()
resizedTestImage = testImage.resize((int(testImageTk.width()*proportion), int(testImageTk.height()*proportion)))
resizedTestImageTk = ImageTk.PhotoImage(resizedTestImage)
canvas.create_image((0,0), image=resizedTestImageTk, anchor="nw")
print("(image width, image height): (" + str(resizedTestImageTk.width()) + " " + str(resizedTestImageTk.height()) + ")")
root.bind("<Configure>", handle_configure)
root.mainloop()
您的新代码在 PhotoImage.
中存在错误问题
在 handle_configure 中你分配给局部变量 resizedTestImageTk 即使你已经创建了 external/global 变量 resizedTestImageTk
如果我通知函数它必须使用 global 通知函数它必须将它分配给外部变量而不是本地变量，它对我有用
def handle_configure(event):
global resizedTestImageTk # <-- inform function to assign image to global variable instead of using local one
或者我将本地 resizedTestImageTk 分配给全局 class.
canvas.resizedTestImageTk = resizedTestImageTk # <-- assign local `resizedTestImageTk` to global class.
最少的工作代码。
我更改了一些计算以使其更具可读性。
import tkinter as tk
from PIL import Image, ImageTk
# --- functions ---
def handle_configure(event):
global resizedTestImageTk # <-- inform function to assign image to global variable instead of using local one
geometry = root.geometry()
window_width = int(geometry[0:geometry.index("x")])
window_height = int(geometry[geometry.index("x")+1:geometry.index("+")])
image_width = testImageTk.height()
image_height = testImageTk.width()
if window_height < window_width:
proportion = window_height / image_height
else:
proportion = window_width / image_width
image_width = int(image_width * proportion)
image_height = int(image_height * proportion)
resizedTestImage = testImage.resize((image_width, image_height))
resizedTestImageTk = ImageTk.PhotoImage(resizedTestImage)
canvas.create_image((0,0), image=resizedTestImageTk, anchor="nw")
#canvas.resizedTestImageTk = resizedTestImageTk # <-- assign local `resizedTestImageTk` to global class.
print(f"(image width, image height): ({image_width} {image_height})")
# --- main ---
root = tk.Tk()
WIDTH = int(root.winfo_screenwidth() * 103/104)
HEIGHT = int(root.winfo_screenheight() * 11/12)
root.geometry('%dx%d+0+0' % (WIDTH, HEIGHT))
canvas = tk.Canvas(root)
canvas.pack(fill="both", expand=True)
testImage = Image.open("lenna.png")
testImageTk = ImageTk.PhotoImage(testImage)
resizedTestImage = None
resizedTestImageTk = None
root.bind("<Configure>", handle_configure)
root.mainloop()
和测试图像
维基百科：Lenna
编辑：
我看到其他问题 - 不太明显。你总是放上新图像但你不删除旧图像 - 所以最终它可能会使用更多内存。
您可以在开始时将图像放在 canvas 上 - 并获取其 ID
image_id = canvas.create_image((0,0), image=testImageTk, anchor="nw")
之后使用 ID
替换图像
canvas.itemconfig(image_id, image=resizedTestImageTk)
最小工作代码：
import tkinter as tk
from PIL import Image, ImageTk
# --- functions ---
def handle_configure(event):
global resizedTestImageTk # <-- inform function to assign image to global variable instead of using local one
geometry = root.geometry()
window_width = int(geometry[0:geometry.index("x")])
window_height = int(geometry[geometry.index("x")+1:geometry.index("+")])
image_width = testImageTk.width()
image_height = testImageTk.height()
if window_height < window_width:
proportion = window_height / image_width
else:
proportion = window_width / image_height
image_width = int(image_width * proportion)
image_height = int(image_height * proportion)
resizedTestImage = testImage.resize((image_width, image_height))
resizedTestImageTk = ImageTk.PhotoImage(resizedTestImage)
canvas.itemconfig(image_id, image=resizedTestImageTk)
#canvas.resizedTestImageTk = resizedTestImageTk # <-- assign local `resizedTestImageTk` to global class.
print(f"(image width, image height): ({image_width} {image_height})")
# --- main ---
image_id = None # default value at start
root = tk.Tk()
WIDTH = int(root.winfo_screenwidth() * 103/104)
HEIGHT = int(root.winfo_screenheight() * 11/12)
root.geometry('%dx%d+0+0' % (WIDTH, HEIGHT))
canvas = tk.Canvas(root)
canvas.pack(fill="both", expand=True)
testImage = Image.open("lenna.png")
testImageTk = ImageTk.PhotoImage(testImage)
resizedTestImage = None
resizedTestImageTk = None
image_id = canvas.create_image((0,0), image=testImageTk, anchor="nw")
root.bind("<Configure>", handle_configure)
root.mainloop()
我目前正在尝试在 canvas 上显示图像。更具体地说，我想让 canvas 上绘制的图像根据 window 的大小调整大小（这样图像总是适合 canvas).
我从一个填满整个屏幕的简单 canvas 开始。
import tkinter as tk
from PIL import Image, ImageTk
root = tk.Tk()
WIDTH, HEIGHT = root.winfo_screenwidth(), root.winfo_screenheight()
root.geometry('%dx%d+0+0' % (WIDTH, HEIGHT))
canvas = tk.Canvas(root)
canvas.pack(fill="both", expand=True)
然后我会设置我的背景图片和可以在背景上调整大小的图片。
backgroundImage = ImageTk.PhotoImage(Image.open("filepath"))
image1 = Image.open("filepath")
image2 = ...
....
....
然后我创建了一个调整图像大小的方法。
"""
This method resizes a image so that all the images fits on the GUI. This first creates an Image object,
but since the Image object does not allow access to the width and height of the Image object, a ImageTk
object needs to be created from the Image object. The ImageTk object cannot resize, but the Image object
can. So using ImageTk object to get the height and width and the Image object to resize, a new Image object
that is resized to fit the GUI is created.
@imageFile- the image file that is being resized
@windowMeasure- the measurement of the window to proportionally resize the image
@useHeight- determine the measurement being proportioned
"""
def resizedImageTk(image, windowMeasure, useHeight):
imageTk = ImageTk.PhotoImage(image)
area = windowMeasure * 4/5
tileSize = area / 4
if useHeight:
proportion = tileSize / imageTk.height()
else:
proportion = tileSize / imageTk.width()
resizedImage = image.resize((int(imageTk.width()*proportion), int(imageTk.height()*proportion)))
resizedImageTk = ImageTk.PhotoImage(resizedImage)
return resizedImageTk
然后我使用一种方法在 window 的大小发生变化时重新绘制调整大小的图像并将其绑定到根。注意：我知道这可能需要大量计算，所以我减少了这种情况发生的次数
numResizes = 0
def handle_configure(event):
if numResizes % 5 == 0:
geometry = root.geometry()
width = int(geometry[0:geometry.index("x")])
height = int(geometry[geometry.index("x")+1:geometry.index("+")])
canvas.create_image((0,0), image=backgroundImageTk, anchor="nw")
if height < width:
measurement = height
else:
measurement = width
resizedImage1 = resizedImageTk(image1, measurement, height < width)
resizedImage2 = ....
....
....
images = [resizedImage1, resizedImage2, ...]
imageWidth = resizedImage1.width()
imageHeight = resizedImage1.height()
i = 0
for row in range(0, int(len(images) / 4)):
for column in range(0, int(len(images) / 5):
x = imageWidth*column + int(width/2) - imageWidth * 2
y = imageHeight*row + int(height/2) - int(imageHeight*2.5)
canvas.create_image((x, y), image=images[i])
i=i+1
numResizes = numResizes + 1
root.bind("<Configure>", handle_configure)
root.mainloop()
我的图像中有 运行 这个，并且取得了一些成功，但是，它并不完全有效。我显示了我的背景图像，但没有显示其他图像。我不知道为什么，因为当我在嵌套的 for 循环（图像未显示）中对 canvas 使用 create_line 函数时，我确实得到了显示的行。
如果有人能对此提出一些建议，我将不胜感激！
谢谢
更新：
这是我正在尝试做的一个简单示例。您可以使用任何示例图像来测试它。
import tkinter as tk
from PIL import Image, ImageTk
root = tk.Tk()
WIDTH, HEIGHT = int(root.winfo_screenwidth() * 103/104), int(root.winfo_screenheight() * 11/12)
root.geometry('%dx%d+0+0' % (WIDTH, HEIGHT))
canvas = tk.Canvas(root)
canvas.pack(fill="both", expand=True)
testImage = Image.open("enter file path here!")
testImageTk = ImageTk.PhotoImage(testImage)
resizedTestImage = None
resizedTestImageTk = None
def handle_configure(event):
geometry = root.geometry()
width = int(geometry[0:geometry.index("x")])
height = int(geometry[geometry.index("x")+1:geometry.index("+")])
useHeight = height < width
if useHeight:
measurement = height
else:
measurement = width
if useHeight:
proportion = measurement / testImageTk.height()
else:
proportion = measurement / testImageTk.width()
resizedTestImage = testImage.resize((int(testImageTk.width()*proportion), int(testImageTk.height()*proportion)))
resizedTestImageTk = ImageTk.PhotoImage(resizedTestImage)
canvas.create_image((0,0), image=resizedTestImageTk, anchor="nw")
print("(image width, image height): (" + str(resizedTestImageTk.width()) + " " + str(resizedTestImageTk.height()) + ")")
root.bind("<Configure>", handle_configure)
root.mainloop()
您的新代码在 PhotoImage.
在 handle_configure 中你分配给局部变量 resizedTestImageTk 即使你已经创建了 external/global 变量 resizedTestImageTk
如果我通知函数它必须使用 global 通知函数它必须将它分配给外部变量而不是本地变量，它对我有用
def handle_configure(event):
global resizedTestImageTk # <-- inform function to assign image to global variable instead of using local one
或者我将本地 resizedTestImageTk 分配给全局 class.
canvas.resizedTestImageTk = resizedTestImageTk # <-- assign local `resizedTestImageTk` to global class.
最少的工作代码。
我更改了一些计算以使其更具可读性。
import tkinter as tk
from PIL import Image, ImageTk
# --- functions ---
def handle_configure(event):
global resizedTestImageTk # <-- inform function to assign image to global variable instead of using local one
geometry = root.geometry()
window_width = int(geometry[0:geometry.index("x")])
window_height = int(geometry[geometry.index("x")+1:geometry.index("+")])
image_width = testImageTk.height()
image_height = testImageTk.width()
if window_height < window_width:
proportion = window_height / image_height
else:
proportion = window_width / image_width
image_width = int(image_width * proportion)
image_height = int(image_height * proportion)
resizedTestImage = testImage.resize((image_width, image_height))
resizedTestImageTk = ImageTk.PhotoImage(resizedTestImage)
canvas.create_image((0,0), image=resizedTestImageTk, anchor="nw")
#canvas.resizedTestImageTk = resizedTestImageTk # <-- assign local `resizedTestImageTk` to global class.
print(f"(image width, image height): ({image_width} {image_height})")
# --- main ---
root = tk.Tk()
WIDTH = int(root.winfo_screenwidth() * 103/104)
HEIGHT = int(root.winfo_screenheight() * 11/12)
root.geometry('%dx%d+0+0' % (WIDTH, HEIGHT))
canvas = tk.Canvas(root)
canvas.pack(fill="both", expand=True)
testImage = Image.open("lenna.png")
testImageTk = ImageTk.PhotoImage(testImage)
resizedTestImage = None
resizedTestImageTk = None
root.bind("<Configure>", handle_configure)
root.mainloop()
和测试图像
维基百科：Lenna
编辑：
我看到其他问题 - 不太明显。你总是放上新图像但你不删除旧图像 - 所以最终它可能会使用更多内存。
您可以在开始时将图像放在 canvas 上 - 并获取其 ID
image_id = canvas.create_image((0,0), image=testImageTk, anchor="nw")
之后使用 ID
替换图像canvas.itemconfig(image_id, image=resizedTestImageTk)
最小工作代码：
import tkinter as tk
from PIL import Image, ImageTk
# --- functions ---
def handle_configure(event):
global resizedTestImageTk # <-- inform function to assign image to global variable instead of using local one
geometry = root.geometry()
window_width = int(geometry[0:geometry.index("x")])
window_height = int(geometry[geometry.index("x")+1:geometry.index("+")])
image_width = testImageTk.width()
image_height = testImageTk.height()
if window_height < window_width:
proportion = window_height / image_width
else:
proportion = window_width / image_height
image_width = int(image_width * proportion)
image_height = int(image_height * proportion)
resizedTestImage = testImage.resize((image_width, image_height))
resizedTestImageTk = ImageTk.PhotoImage(resizedTestImage)
canvas.itemconfig(image_id, image=resizedTestImageTk)
#canvas.resizedTestImageTk = resizedTestImageTk # <-- assign local `resizedTestImageTk` to global class.
print(f"(image width, image height): ({image_width} {image_height})")
# --- main ---
image_id = None # default value at start
root = tk.Tk()
WIDTH = int(root.winfo_screenwidth() * 103/104)
HEIGHT = int(root.winfo_screenheight() * 11/12)
root.geometry('%dx%d+0+0' % (WIDTH, HEIGHT))
canvas = tk.Canvas(root)
canvas.pack(fill="both", expand=True)
testImage = Image.open("lenna.png")
testImageTk = ImageTk.PhotoImage(testImage)
resizedTestImage = None
resizedTestImageTk = None
image_id = canvas.create_image((0,0), image=testImageTk, anchor="nw")
root.bind("<Configure>", handle_configure)
root.mainloop()