访问照片

Question

下午好，我使用Python和Kivy编写了一个简单的相机程序，但我只是无法拍照。您需要拍摄“ ScreenThree”的快照（将其保存在手机的内存中），然后在“ ScreenFour”上显示生成的图像。

我使用kivy.uix.camera显示相机，kivymd和kv创建界面。 android.permissions：INTERNET，CAMERA，WRITE_EXTERNAL_STORAGE，READ_EXTERNAL_STORAGE

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.camera import Camera
from kivymd.theming import ThemeManager

import time

Builder.load_string("""
#:import MDFillRoundFlatButton kivymd.button.MDFillRoundFlatButton
#:import MDIconButton kivymd.button.MDIconButton
<ScreenOne@Screen>:
    canvas:
        Color:
            rgb: [.30,.50,.99]
        Rectangle:
            pos: self.pos
            size: self.size
    FloatLayout:
        MDFillRoundFlatButton:
            color: [1,1,1,1]
            text: "Перейти к созданию фото"
            pos_hint: {'center_x':.50, 'center_y':.50}
            on_press:
                root.manager.transition.direction = 'up'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_two'

<ScreenTwo@Screen>:
    canvas:
        Color:
            rgb: [.30,.50,.99]
        Rectangle:
            pos: self.pos
            size: self.size
    FloatLayout:
        MDFillRoundFlatButton:
            color: [1,1,1,1]
            text: "Выбрать фон"
            pos_hint: {'center_x':.50, 'center_y':.10}
            on_press:
                root.manager.transition.direction = 'up'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_three'
        MDIconButton:
            icon: 'chevron-double-right'
            pos_hint: {'center_x':.95, 'center_y':.10}
            on_press:
                root.manager.transition.direction = 'down'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_one'

<ScreenThree@Screen>:
    id: entry
    canvas:
        Color:
            rgb: [.30,.50,.99]
        Rectangle:
            pos: self.pos
            size: self.size
    FloatLayout:
        Camera:
            id: camera
            index: 0
            resolution: (1280,720)
            play: True  
        MDFillRoundFlatButton:
            text: "take photo"
            pos_hint: {'center_x': 0.50, 'center_y': .10}
            on_press:
                root.capture()   #TAKE PHOTO
                root.manager.transition.direction = 'up'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_four'    
        MDIconButton:
            icon: 'chevron-double-right'
            pos_hint: {'center_x':.95, 'center_y':.10}
            on_press:
                root.manager.transition.direction = 'down'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_two'

<ScreenFour@Screen>:
    canvas:
        Color:
            rgb: [.30,.50,.99]
        Rectangle:
            pos: self.pos
            size: self.size
    FloatLayout:
# HERE I NEED TO DISPLAY THE IMAGE
        MDIconButton:
            icon: 'chevron-double-right'
            pos_hint: {'center_x':.95, 'center_y':.10}
            on_press:
                root.manager.transition.direction = 'down'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_three'
""")


class ScreenOne(Screen):
    pass


class ScreenTwo(Screen):
    theme_cls = ThemeManager()
    theme_cls.primary_palette = 'Blue'
    main_widget = None

class ScreenThree(Screen):
    theme_cls = ThemeManager()
    theme_cls.primary_palette = 'Blue'
    main_widget = None

    def capture(self):
        camera = self.ids['camera']
        timestr = time.strftime("%Y%m%d_%H%M%S")
        photo = camera.export_to_png("IMG_{}.png".format(timestr))
        print("Captured")



class ScreenFour(Screen):
    pass


screen_manager = ScreenManager()


screen_manager.add_widget(ScreenOne(name="screen_one"))
screen_manager.add_widget(ScreenTwo(name="screen_two"))
screen_manager.add_widget(ScreenThree(name="screen_three"))
screen_manager.add_widget(ScreenFour(name="screen_four"))


class Interface(App):

    def build(self):
        return screen_manager

sample_app = Interface()
sample_app.run()

请告诉我，如何修改代码以完成任务。

错误

Take photo White screen

04-08 21:15:19.925   796 13801 E mm-camera: <STATS_AF ><ERROR> 959: af_spd_detect_process: ERROR! SPOT_LIGHT_FLAG =0!!! :AEC_grid = 256, BG_grid = 3072, ave luma = 0
04-08 21:15:19.933   835   902 W SurfaceFlinger: EventThread: dropping event (7673796e) for connection 0x7b332278c0
04-08 21:15:19.949   835   902 W SurfaceFlinger: EventThread: dropping event (7673796e) for connection 0x7b332278c0
04-08 21:15:19.959   796 13801 E mm-camera: <STATS_AF ><ERROR> 959: af_spd_detect_process: ERROR! SPOT_LIGHT_FLAG =0!!! :AEC_grid = 256, BG_grid = 3072, ave luma = 0
04-08 21:15:19.966   835   902 W SurfaceFlinger: EventThread: dropping event (7673796e) for connection 0x7b332278c0
04-08 21:15:19.983   835   902 W SurfaceFlinger: EventThread: dropping event (7673796e) for connection 0x7b332278c0
04-08 21:15:19.992   796 13801 E mm-camera: <STATS_AF ><ERROR> 959: af_spd_detect_process: ERROR! SPOT_LIGHT_FLAG =0!!! :AEC_grid = 256, BG_grid = 3072, ave luma = 0
04-08 21:15:19.999   835   902 W SurfaceFlinger: EventThread: dropping event (7673796e) for connection 0x7b332278c0

错误2

04-09 08:27:25.140   796  6243 E mm-camera: <STATS_AF ><ERROR> 959: af_spd_detect_process: ERROR! SPOT_LIGHT_FLAG =0!!! :AEC_grid = 256, BG_grid = 3072, ave luma = 0
04-09 08:27:25.146   835   902 W SurfaceFlinger: EventThread: dropping event (7673796e) for connection 0x7b32a54420
04-09 08:27:25.146  6164  6198 I python  : Captured
04-09 08:27:25.147  6164  6198 I python  : [ERROR  ] [Image       ] Error reading file IMG_20190409_082724.png
04-09 08:27:25.162   835   902 W SurfaceFlinger: EventThread: dropping event (7673796e) for connection 0x7b32a54420
04-09 08:27:25.175   796  6243 E mm-camera: <STATS_AF ><ERROR> 959: af_spd_detect_process: ERROR! SPOT_LIGHT_FLAG =0!!! :AEC_grid = 256, BG_grid = 3072, ave luma = 0
04-09 08:27:25.179   835   902 W SurfaceFlinger: EventThread: dropping event (7673796e) for connection 0x7b32a54420

Answer 1

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.camera import Camera
from kivymd.theming import ThemeManager

import time

filename = ''
screenfour = ''

Builder.load_string("""
#:import MDFillRoundFlatButton kivymd.button.MDFillRoundFlatButton
#:import MDIconButton kivymd.button.MDIconButton
<ScreenOne@Screen>:
    canvas:
        Color:
            rgb: [.30,.50,.99]
        Rectangle:
            pos: self.pos
            size: self.size
    FloatLayout:
        MDFillRoundFlatButton:
            color: [1,1,1,1]
            text: "Перейти к созданию фото"
            pos_hint: {'center_x':.50, 'center_y':.50}
            on_press:
                root.manager.transition.direction = 'up'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_two'

<ScreenTwo@Screen>:
    canvas:
        Color:
            rgb: [.30,.50,.99]
        Rectangle:
            pos: self.pos
            size: self.size
    FloatLayout:
        MDFillRoundFlatButton:
            color: [1,1,1,1]
            text: "Выбрать фон"
            pos_hint: {'center_x':.50, 'center_y':.10}
            on_press:
                root.manager.transition.direction = 'up'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_three'
        MDIconButton:
            icon: 'chevron-double-right'
            pos_hint: {'center_x':.95, 'center_y':.10}
            on_press:
                root.manager.transition.direction = 'down'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_one'

<ScreenThree@Screen>:
    id: entry
    canvas:
        Color:
            rgb: [.30,.50,.99]
        Rectangle:
            pos: self.pos
            size: self.size
    FloatLayout:
        Camera:
            id: camera
            index: 0
            resolution: (1280,720)
            play: True
        MDFillRoundFlatButton:
            text: "take photo"
            pos_hint: {'center_x': 0.50, 'center_y': .10}
            on_press:
                root.capture()   #TAKE PHOTO
                root.manager.transition.direction = 'up'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_four'
        MDIconButton:
            icon: 'chevron-double-right'
            pos_hint: {'center_x':.95, 'center_y':.10}
            on_press:
                root.manager.transition.direction = 'down'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_two'

<ScreenFour@Screen>:
    canvas:
        Color:
            rgb: [.30,.50,.99]
        Rectangle:
            pos: self.pos
            size: self.size
    FloatLayout:
        Image:
            size: root.width, root.height
            source: ''
            id: imageWid
        MDIconButton:
            icon: 'chevron-double-right'
            pos_hint: {'center_x':.95, 'center_y':.10}
            on_press:
                root.manager.transition.direction = 'down'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_three'
""")


class ScreenOne(Screen):
    pass


class ScreenTwo(Screen):
    theme_cls = ThemeManager()
    theme_cls.primary_palette = 'Blue'
    main_widget = None

class ScreenThree(Screen):
    theme_cls = ThemeManager()
    theme_cls.primary_palette = 'Blue'
    main_widget = None

    def capture(self):
        camera = self.ids['camera']
        timestr = time.strftime("%Y%m%d_%H%M%S")
        photo = camera.export_to_png("IMG_{}.png".format(timestr))
        global filename, screenfour
        filename = "IMG_{}.png".format(timestr)
        print("Captured")
        screenfour.update()

class ScreenFour(Screen):
    def __init__(self, **kwargs):
        super(ScreenFour, self).__init__(**kwargs)
        global screenfour
        screenfour = self

    def update(self, *args):
        global filename
        imageWidget = self.ids['imageWid']
        imageWidget.source = filename

screen_manager = ScreenManager()

screen_manager.add_widget(ScreenOne(name="screen_one"))
screen_manager.add_widget(ScreenTwo(name="screen_two"))
screen_manager.add_widget(ScreenThree(name="screen_three"))
screen_manager.add_widget(ScreenFour(name="screen_four"))

class Interface(App):

    def build(self):
        return screen_manager

sample_app = Interface()
sample_app.run()

您将创建一个global变量来保存图片的文件名，然后在屏幕上的Image中创建一个Screen小部件，在此您将Image小部件的源更新为文件名拍摄的照片。如有任何问题，请随时与我联系

Answer 2

访问照片

使用以下方法引用照片：

class ScreenFour(Screen):

    def on_pre_enter(self, *args):
        self.ids.img.source = self.manager.ids.entry.photo

解决方案

注意

<class-name@widget>:

这是dynamic class。使用动态类时，无需在Python脚本中定义类。

kv文件

通过删除所有@Screen，将所有动态类更改为类规则。
添加类别规则<ScreenManagement>:
将所有屏幕实例化为类规则<ScreenManagement>:的子级
在实例化的子对象ScreenThree下添加id: entry：
实例化Image:作为类规则FloatLayout:的{{1}}的子代
在实例化子项<ScreenFour>:下添加id: img

摘要

Image:

Py文件

添加导入语句#:import MDIconButton kivymd.button.MDIconButton <ScreenManagement>: ScreenOne: name: "screen_one" ScreenTwo: name: "screen_two" ScreenThree: id: entry name: "screen_three" ScreenFour: name: "screen_four" ... <ScreenFour>: canvas: Color: rgb: [.30,.50,.99] Rectangle: pos: self.pos size: self.size FloatLayout: Image: id: img
添加导入语句from os.path import dirname
添加from kivy.properties import StringProperty
删除所有对class ScreenManagement()的引用
声明类属性，screen_manager下的photo = StringProperty('')
初始化类属性class ScreenThree()
实施方法self.photo = f"{dirname(__file__)}/IMG_{time.strftime('%Y%m%d_%H%M%S')}.png"以显示照片。

摘要

on_pre_enter()

示例

main.py

from os.path import dirname
from kivy.properties import StringProperty
...
class ScreenThree(Screen):
    photo = StringProperty('')

    def capture(self):
        camera = self.ids['camera']
        self.photo = f"{dirname(__file__)}/IMG_{time.strftime('%Y%m%d_%H%M%S')}.png"
        camera.export_to_png(self.photo)
        print("Captured")


class ScreenFour(Screen):

    def on_pre_enter(self, *args):
        self.ids.img.source = self.manager.ids.entry.photo


class ScreenManagement(ScreenManager):
    pass


class Interface(App):

    def build(self):
        return ScreenManagement()

如何制作图像并将其显示在下一页上

错误

错误2

2 个答案:

访问照片

解决方案

注意

kv文件

摘要

Py文件

摘要

示例

main.py

输出