Django Model Admin:如何自动分配和隐藏当前用户的created_by字段，并在保存后显示？

from django.db import models
from django.contrib.auth.models import User

class MyModel(models.Model):
    # 其他字段...
    created_by = models.ForeignKey(User, null=True, on_delete=models.SET_NULL)

from django.contrib import admin

class MyModelAdmin(admin.ModelAdmin):
    def get_form(self, request, obj=None, **kwargs):
        form = super().get_form(request, obj, **kwargs)
        form.current_user = request.user
        return form

from django import forms

class MyModelForm(forms.ModelForm):
    def save(self, commit=True):
        instance = super().save(commit=False)
        instance.created_by = self.current_user
        if commit:
            instance.save()
        return instance

class MyModelAdmin(admin.ModelAdmin):
    form = MyModelForm