안드로이드 스튜디오에서 Interface CallbackEvent를 생성하고 나서 EventRegistration Class 에서 CallbackEvent 변수를 선언하고 생성자 만들기를 하면 자동으로 생성자가 만들어지는 걸 볼 수 있다.
public interface CallbackEvent {
// 1 Step 인터페이스 정의
public void callbackMethod();
} |
public class EventRegistration {
// 2 Step 변수 선언
CallbackEvent callbackEvent;
// 3 Step 생성자 생성
public EventRegistration(CallbackEvent callbackEvent) {
System.out.println("2. EventRegistration Constructor");
this.callbackEvent = callbackEvent;
}
public void doWork(){
System.out.println("4. doWork 메소드");
callbackEvent.callbackMethod();
}
} |
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
System.out.println("1. MainActivity");
CallbackEvent callbackEvent = new CallbackEvent() {
@Override
public void callbackMethod() {
System.out.println("5. call callback method from callee");
}
};
EventRegistration eventRegistration = new EventRegistration(callbackEvent);
System.out.println("3. eventRegistration.doWork()");
eventRegistration.doWork();
}
} |
생성자 생성과 동시에 EventRegistration(CallbackEvent callbackEvent) 를 지정하는 방법과
별도 setCallbackEvent(CallbackEvent callbackEvent) 를 하는 방법으로 구분해서 해보고 있다.
public interface CallbackEvent {
// 1 Step 인터페이스 정의
public void callbackMethod();
} |
public class EventRegistration {
Context mContext;
// 2 Step 변수 선언
CallbackEvent callbackEvent;
// 3 Step 생성자 선언
public EventRegistration(Context context) {
System.out.println("3. EventRegistration Constructor");
mContext = context;
}
// 4 Step CallbackEvent Set
public void setCallbackEvent(CallbackEvent callbackEvent){
System.out.println("5. setCallbackEvent");
this.callbackEvent = callbackEvent;
}
public void doWork(){
System.out.println("7. doWork 메소드 응답");
callbackEvent.callbackMethod();
}
} |
public class MainActivity extends AppCompatActivity {
Context context;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context = getBaseContext();
System.out.println("1. MainActivity 실행");
System.out.println("2. EventRegistration 생성자 호출");
EventRegistration eventRegistration = new EventRegistration(context);
System.out.println("4. setCallbackEvent 연동");
eventRegistration.setCallbackEvent(new CallbackEvent() {
@Override
public void callbackMethod() {
System.out.println("8. call callback method from callee");
}
});
System.out.println("6. eventRegistration.doWork() 실행");
eventRegistration.doWork();
}
} |
예제3.
안드로이드에서 보편적으로 사용되는 예제이다.
public interface CallbackEvent {
void callbackMethod();
}
|
import android.content.Context;
public class NewClass {
private Context mContext;
private CallbackEvent callbackEvent;
public NewClass(Context mContext) {
System.out.println("2. NewClass Constructor");
this.mContext = mContext;
}
public void setCallbackEvent(CallbackEvent callbackEvent){
System.out.println("3. setCallbackEvent");
this.callbackEvent = callbackEvent;
}
public void doWork(){
//Do somthing...
//call back main
callbackEvent.callbackMethod();
System.out.println("5. doWork 메소드 응답");
}
}
|
import android.content.Context;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity implements CallbackEvent {
Context mContext;
NewClass newClass;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mContext = MainActivity.this;
System.out.println("1. MainActivity 실행");
doSomething();
}
private void doSomething(){
newClass = new NewClass(mContext);
newClass.setCallbackEvent(this);
newClass.doWork();
System.out.println("6. newClass.doWork()");
}
@Override
public void callbackMethod() {
System.out.println("4. callbackMethod from callee.");
}
}
|
