How to display python matplotlib graphs (png) with Chaquopy in Android Studio

问题

So I use chaquopy to get simple python programs functioning in an old (jelly bean) tablet (I replace the example console app's main.py in the src directory). Not bad for a beginner's start and I'm very happy.

But now for a test I try to display a matplotlib graph like this:

import matplotlib.pyplot as plt
import matplotlib.image as mpimg
def main():

    image = mpimg.imread("/storage/emulated/0/Documents/test.png")
    plt.imshow(image)
    plt.show() 

The matplotlib library was installed from within android studio (albeit with a few missing elements, manual pip3 install and usage of local files). Now the build and program finish without errors, but there is no graph. Installation of pillow and use of other graph types no avail.

Can this be handled in python, or is a dive into android studio / java required?

Thanks for any advice

回答1:

You'll have to include an ImageView in your app's layout, and then load the image file into it, as in this answer.

For an image which is generated dynamically by matplotlib, either save it to a file and then load from that file, or save it to a bytes object like this:

import io
bio = io.BytesIO()
plt.savefig(bio, format="png")
b = bio.getvalue()

... and then load that bytes object into the ImageView like in this app.

来源：https://stackoverflow.com/questions/53285429/how-to-display-python-matplotlib-graphs-png-with-chaquopy-in-android-studio