Kivy用jnius调用Intent选图库图片闪退报No running App found错误求助

闪退根本原因 #

• on_activity_result回调函数中引用了未定义的变量：currentActivity、layout、webview，调用不存在的变量直接触发未捕获异常，导致Kivy主循环崩溃退出，最终抛出NoneType无run属性的报错
• Push函数定义要求传入callback参数，但是按钮on_press绑定时没有传入对应参数，实际调用时默认传入的是按钮实例，后续调用callback(None)会出现类型错误
• 每次点击按钮都会重复绑定on_activity_result事件，多次绑定会导致回调被重复触发，引发逻辑混乱
• 未申请Android读取存储的动态权限，Android 6.0+版本访问系统图库内容必须先申请READ_EXTERNAL_STORAGE权限，否则访问内容提供器时会崩溃

修复后的完整代码 #

from android.runnable import run_on_ui_thread as run_thread
from jnius import autoclass, cast
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
from kivy.app import App
from android import activity as act
from android.permissions import request_permissions, Permission

# 提前申请读取存储权限
request_permissions([Permission.READ_EXTERNAL_STORAGE])

Uri = autoclass('android.net.Uri')
MediaStore_Images_Media_DATA = "_data"
RESULT_LOAD_IMAGE = 1
PythonActivity = autoclass('org.kivy.android.PythonActivity')
Intent = autoclass('android.content.Intent')
Activity = autoclass('android.app.Activity')

# 全局只绑定一次activity结果回调
def on_activity_result(request_code, result_code, intent):
    if request_code != RESULT_LOAD_IMAGE:
        return
    if result_code == Activity.RESULT_CANCELED:
        print("用户取消选择")
        return
    if result_code != Activity.RESULT_OK:
        print(f"未知返回码：{result_code}")
        return
    activity = cast('android.app.Activity', PythonActivity.mActivity)
    selectedImage = intent.getData()
    filePathColumn = [MediaStore_Images_Media_DATA]
    cursor = activity.getContentResolver().query(selectedImage, filePathColumn, None, None, None)
    cursor.moveToFirst()
    columnIndex = cursor.getColumnIndex(filePathColumn[0])
    picturePath = cursor.getString(columnIndex)
    cursor.close()
    print(f"选中的图片路径：{picturePath}")

act.bind(on_activity_result=on_activity_result)

@run_thread
def push(instance):
    activity1 = cast('android.app.Activity', PythonActivity.mActivity)
    intent= Intent(Intent.ACTION_GET_CONTENT)
    intent.addCategory(Intent.CATEGORY_OPENABLE)
    intent.setType("image/*")
    activity1.startActivityForResult(intent, RESULT_LOAD_IMAGE)

class GalleryApp(App):
    def build(self):
        m=GridLayout(cols=1,rows=1)
        d=GridLayout(cols=1,rows=1)
        m.add_widget(d)
        b=Button(text="打开图库")
        b.bind(on_press=push)
        d.add_widget(b)
        return m

if __name__ == "__main__":
    GalleryApp().run()

额外注意事项 #

• 原代码中操作layout、webview的逻辑因为没有对应的变量定义，已经删除，如果确实需要操作WebView，需要先正确实例化对应对象再操作
• buildozer.spec文件中需要添加权限声明：android.permissions = READ_EXTERNAL_STORAGE

内容的提问来源于stack exchange，提问作者koushik