Koin simple to use

Koin What is it? ？ Why use Koin?

Koin Is an injection framework without reflection / agent It is convenient to use objects to call a class object and use the methods inside the class object .

I don't understand , Here is just to teach you how to practice Koin, Only because it is used in the project as a last resort

Koin From an open source Author

Inside Koin 3.2 - Optimizing your Modules with Includes

Its wood is for Kotlin Convenient and fast injection , Before that, there is another open source annotation Degger2 No description here , Self Baidu in need

There are several steps to use ：

First 1. What is the object you want to inject , That is, the class you are going to use

Here we use  

LoginPresenter  For example 

 

class LoginPresenter(val login: LoginModel) {

    fun login()：Boolen{
        return login.do()
    }

}

2.LoginPresenter  Required parameter classes  LoginModel

  

interface LoginModel{
    fun do(): Boolean
}

class LoginModelImpl : LoginModel{

    override fun do(): Boolean {
        // to do login ...  Some logic to log in is omitted here 
        return true
    }
}

3. Create a new class AppMoudle  The classes to be injected Use Koin Of model To register

package com.nova.di

import com.nova.koin.HelloRepository
import com.nova.koin.HelloRepositoryImpl
import com.nova.koin.MySimplePresenter
import org.koin.dsl.module

/**
 * @author Created by Li
 * 2022/7/14
 */

val appModule = module {
    // single  Represents a singleton 
    single<LoginModel> { LoginModelImpl() }
   // factory  Indicates factory   get()   Indicates that the parameters registered above are automatically brought in 
    factory { LoginPresenter(get()) }
}

4. stay Application Start injecting objects at

class MyApplication : Application() {
   
    override fun onCreate() {
        super.onCreate()

        startKoin {
            // Level.NONE
            androidLogger()
            androidContext([email protected])
            modules(appModule)
        }

    }
}

5. Get the injected object on the called page LoginPresenter

class KoinActivity : AppCompatActivity() {
    private val TAG = "KoinActivity"
    val loginPresenter: LoginPresenter by inject()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_loin)

        if (loginPresenter!= null)
            LogUtil.d(TAG, "${loginPresenter.login()}")
    }

}

In fact, an error will be reported when it is run after completion , Here is a pit to use when starting injection

androidLogger()  Will report a mistake

java.lang.NoSuchMethodError: No virtual method elapsedNow()D in class Lkotlin/time/TimeMark; or its super classes (declaration of 'kotlin.time.TimeMark' appears in /data/app/~~ArLPm6ZwWHpL7fiTI_vDjQ==/com.nova.fraworkproject-QE0TR4fU0SiejzRkgwjc2w==/base.apk)

The following settings should be used *********

androidLogger( Level.NONE)

class MyApplication : Application() {
    private var mActivitRouter: ActivitRouter? = null

    override fun onCreate() {
        super.onCreate()

        startKoin {
            // Level.NONE
            androidLogger( Level.NONE)
            androidContext([email protected])
            modules(appModule)
        }
    }
}

As for how to use it, that's all , If it helps you, please pay more attention ,day day up.