simple

1. 生成 wire文件

wire

2.运行

go run wire_gen.go main.go

wire_gen文件内容如下

// Code generated by Wire. DO NOT EDIT.

//go:generate go run github.com/google/wire/cmd/wire
//+build !wireinject

package main

// Injectors from wire.go:

func InitializeBusiness() *Business {
	db := NewDB()
	dao := NewDao(db)
	business := NewBusiness(dao)
	return business
}