간단한 안드로이드 세미나 2

1. ANDROID 세미나
FOR BEGINNER (2)
PoolC 홍철주
2012. 4. 18

2. RESOURCE -> SOURCE CODE
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>

3. RESOURCE -> SOURCE CODE

4. RESOURCE -> SOURCE CODE
public class TestActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button mButton = (Button)findViewById(R.id.button1);
}
}

5. RESOURCE -> SOURCE CODE
public final class R {
public static final class attr {
}
public static final class drawable {
public static final int ic_launcher=0x7f020000;
}
public static final class id {
public static final int button1=0x7f050000;
}
public static final class layout {
public static final int main=0x7f030000;
}
public static final class string {
public static final int app_name=0x7f040001;
public static final int hello=0x7f040000;
}
}

6. RESOURCE -> SOURCE CODE
{ResourceType} {Varible} = (ResourceType)findViewById(ResourceAddress);

7. RESOURCE -> SOURCE CODE
Button mButton = (Button)findViewById(R.id.button1);
// Button Listener : onClick -> call a function
mButton.setOnClickListener(new Button.OnClickListener(){
public void onClick(View v) {
// TODO Auto-generated method stub
Toast.makeText(getApplicationContext(), "Hello, World",
Toast.LENGTH_SHORT).show();
}
});

8. ACTIVITY
• 일단은 보이는 화면이라고 생각
• 당신은 화면 위에다가 터치도 하고 이것 저것한다
• 입력도 받고 출력도 받고
• 액티비티 주기를 볼 필요가 있긴 한데...

9. INTENT
• 안드로이드에서의 의사표현 수단
• 어떤 component를 부른다!
• 그리고 무엇을 해달라고 요청!

10. CONTEXT
• 어플리케이션 환경의 전역 정보에 접근하기 위한 인터
페이스
• 시스템 정보 접근, API 호출
• 액티비티간 리소스 공유 등..

11. INTENT -> NEW ACTIVITY!
Intent mIntent = new Intent(TestActivity.this, SecondActivity.class);
startActivity(mIntent);
Intent 의 생성자는 여러가지.
이는 그 중 하나.

12. SIMPLE CALCULATOR
op1
opr
op2
result

13. SIMPLE CALCULATOR
EditText op1, op2;
TextView opr, result;
Button plus, minus, mul, div;

14. SIMPLE CALCULATOR
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
op1 = (EditText)findViewById(R.id.op1);
op2 = (EditText)findViewById(R.id.op2);
opr = (TextView)findViewById(R.id.opr);
result = (TextView)findViewById(R.id.result);
plus = (Button)findViewById(R.id.plus);
plus.setOnClickListener(this);
minus = (Button)findViewById(R.id.minus);
minus.setOnClickListener(this);
mul = (Button)findViewById(R.id.mul);
mul.setOnClickListener(this);
div = (Button)findViewById(R.id.div);
div.setOnClickListener(this);
}
this? -> activity
public class TestActivity extends Activity implements View.OnClickListener

15. SIMPLE CALCULATOR
public void onClick(View v) {
// TODO Auto-generated method stub
switch(v.getId()) {
case R.id.plus:
process(Operator.plus);
break;
case R.id.minus:
process(Operator.minus);
break;
case R.id.mul:
process(Operator.mul);
break;
case R.id.div:
process(Operator.div);
break;
}
}

16. SIMPLE CALCULATOR
void process(Operator op)
{
int op1Num = Integer.parseInt(op1.getText().toString());
int op2Num = Integer.parseInt(op2.getText().toString());
double resultNum = 0;
switch(op)
{
case plus:
resultNum = op1Num + op2Num;
opr.setText("+");
break;
case minus:
resultNum = op1Num - op2Num;
opr.setText("-");
break;
case mul:
resultNum = op1Num * op2Num;
opr.setText("*");
break;
case div:
resultNum = (double)op1Num / op2Num;
opr.setText("/");
break;
}
result.setText(Double.toString(resultNum));