如何访问Python类的变量

Question

我有以下代码可以使用blender启用文件浏览器：

import bpy
import os
from bpy.props import StringProperty
from bpy_extras.io_utils import ImportHelper
from bpy.types import Operator
sel = ''
class OpenBrowser(bpy.types.Operator):
    bl_idname = "open.file"
    bl_label = "Select Excel File"
    bli_description = "Simulation output excel file"
    filter_glob: StringProperty(default = '*.xls;*.xlsx',options = {'HIDDEN'})
    filepath: bpy.props.StringProperty(subtype="FILE_PATH")
    #somewhere to remember the address of the file

    def execute(self, context):
        global sel
        sel = self.filepath 
        #self.selected_file = self.filepath
        #display = "filepath= "+self.filepath  
        #print(display) #Prints to console  
        #Window>>>Toggle systen console

        return {'FINISHED'}

    def invoke(self, context, event): # See comments at end  [1]
        context.window_manager.fileselect_add(self)
        global sel 
        sel = self.filepath
        #Open browser, take reference to 'self' 
        #read the path to selected file, 
        #put path in declared string type data structure self.filepath

        return {'RUNNING_MODAL'}  
        # Tells Blender to hang on for the slow user input


bpy.utils.register_class(OpenBrowser) 
#Tell Blender this exists and should be used


# [1] In this invoke(self, context, event) is being triggered by the below command
#but in your script you create a button or menu item. When it is clicked
# Blender runs   invoke()  automatically.

#execute(self,context) prints self.filepath as proof it works.. I hope.

bpy.ops.open.file('INVOKE_DEFAULT')
print(sel)

我面临的问题是，我已经声明了一个全局变量sel，我希望在运行代码时将从用户选择的文件路径保存到该变量。但是，当我运行脚本时，我看到sel没有改变，它与初始化时一样。有人能帮助我如何从类中访问self.filepath变量吗？我做错了什么

Answer 1

如果我理解正确，您希望存储该值以备将来使用。 我不确定为什么在您的情况下“sel”甚至不更新，但我认为更正确的方法是使用这样的property：

import bpy

# Assign a custom property to an existing type.
bpy.types.Scene.my_sel_value = bpy.props.StringProperty(name="Sel")

# Set property value.
bpy.context.scene.my_sel_value = "Foo"

# Get property value.
print(bpy.context.scene.my_sel_value)

属性可以添加到所有ID类型，但对于“全局”值，通常使用^us。虽然一个项目中可以有多个场景，但它们将具有单独的值。搅拌机关闭时存储属性值

如果您正在制作一个插件，您还可以将您的值存储在Addon Preferences中。此值对于所有blender项目都相同