Why is my field `null` after injection? How do I inject my object?

The above includes both constructor and field injection, but neither done right. The example would behave the same if we removed all the @Inject annotations from MyPresenter since we’re not using any of them. @Provides MyPresenter provideMyPresenter(MyView view) { // no constructor injection, we create the object ourselves! return new MyPresenter(view); } // also no … Read more

Dagger 2 subcomponents vs component dependencies

Component dependencies – Use this when you want to keep two components independent. Subcomponents – Use this when you want to keep two components coupled. I will use the below example to explain Component dependencies and Subcomponents. Some points worth noticing about the example are: SomeClassA1 can be created without any dependency. ModuleA provides and … Read more

Error : Program type already present: android.support.design.widget.CoordinatorLayout$Behavior

It worked when I downgrade the support appcompat gradle dependency, like follwing : implementation ‘com.android.support:appcompat-v7:27.0.2’ previously it was implementation ‘com.android.support:appcompat-v7:27.1.0’ OR Also this can be fixed by just adding support design dependency of version 27.1.0 or above to your app level build.gradle as following : implementation ‘com.android.support:design:27.1.0’

How to set up DAGGER dependency injection from scratch in Android project?

Guide for Dagger 2.x (Revised Edition 6): The steps are the following: 1.) add Dagger to your build.gradle files: top level build.gradle: . // Top-level build file where you can add configuration options common to all sub-projects/modules. buildscript { repositories { jcenter() } dependencies { classpath ‘com.android.tools.build:gradle:2.2.0’ classpath ‘com.neenbedankt.gradle.plugins:android-apt:1.8’ //added apt for source code generation … Read more

Singleton object becomes null after app is resumed

You’re getting crashes because you initialize those variables in one Activity, and expect it to be set always, in the other Activity. But Android doesn’t work like that, you can easily end up crashing because after low memory condition happens, only the current Activity gets recreated at first, previous Activity is recreated on back navigation, … Read more