创建后可以更改 Canvas 对象的属性吗? [英] Can you change the attributes of a Canvas object after creation?

问题描述

我正在尝试模拟一个美国交通灯，在一个矩形上有 3 个圆圈，所有圆圈都绘制在一组 Canvas 上.模拟应该通过按以下顺序每 2 秒更改显示的灯光来镜像动画":绿色 > 黄色 > 红色 > 绿色，等等.

I'm trying to simulate an American traffic light, with 3 circles on a rectangle, all drawn on a set Canvas. The simulation is supposed to mirror "animation" by changing which light is displayed every 2 seconds in the following order: green > yellow > red > green, etc forever.

我能想到的唯一方法是使用 canvas.move()、canvas.after()、canvas.update() 模式移动一个填充的椭圆对象，一次叠加一个未填充的圆.我已经掌握了以正确的速度和正确的顺序移动一个圆圈的逻辑.问题是，我只是实例化了一个充满绿色"的圆圈，但我无法使用这种方法将其更改为黄色"或红色".必须每 2 秒使用 canvas.delete("filled") 并在不同的地方重新绘制它，这似乎很愚蠢，因为对于这样一个简单的程序来说，这需要做很多事情.

The only way I can think of to do this is by using a canvas.move(), canvas.after(), canvas.update() pattern to move a filled oval object to superimpose one unfilled circle at a time. I've gotten the logic down to move a circle at the proper speed and in the correct order. The thing is, I just instantiate a circle filled with "green", but I can't change it to be "yellow" or "red" using this method. It seems silly to have to canvas.delete("filled") and redraw it in a new place with a different fill every 2 seconds, because that's a lot to do for such a simple program.

问题 1:有没有办法可以使用某种方法或其他方式随意更改已填充 Canvas 对象的 fill 选项?

Question 1: Is there a way I can just alter the fill option for my filled Canvas object at will, using some method or other means?

问题 2:我是否错误地处理了这种情况?有没有更好的方法来模拟这个?

Question 2: Am I approaching this scenario incorrectly? Is there a better way to simulate this?

推荐答案

是的，您应该能够通过 config().

Yes you should be able to change settings of the canvas with config().

同样，使用 itemconfig() 更改画布上的项目.这确实需要您保存项目的句柄或标记它们.

Likewise, use itemconfig() to change items on the canvas. This does require that you save a handle to the item or tag them.

基于 tkinterbook 的示例:

Example based on tkinterbook:

item = canvas.create_line(xy, fill="red")

canvas.coords(item, new_xy) # change coordinates
canvas.itemconfig(item, fill="blue") # change color

这篇关于创建后可以更改 Canvas 对象的属性吗?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！