SurfaceView　Androidで画面を高速描画する

SurfaceViewは高速に画面の描画を行い、ゲームやマルチメディアなど高速処理に向いています。

SurfaceViewの基本的なSampl Code

public class MainActivity extends AppCompatActivity {
    private Bitmap mImage;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new SurfaceViewTestClass(this)); // SurfaceViewのインスタンスを生成
    }
    
    public class SurfaceViewTestClass extends SurfaceView implements SurfaceHolder.Callback {
        
        //コンストラクタ
        public SurfaceViewTestClass(Context context) {
            super(context);
            getHolder().addCallback(this);
        }
        
        public void surfaceCreated(SurfaceHolder holder) {
            Paint paint = new Paint();
            paint.setTextSize(30);
            paint.setColor(Color.WHITE);
            paint.setStyle(Paint.Style.FILL);
            
            // image取得
            mImage = BitmapFactory.decodeResource(getResources(), R.drawable.image);
            
            Canvas canvas = holder.lockCanvas(); // Canvas lock
            
            canvas.drawBitmap(mImage, 10, 10, paint);
            canvas.drawText("TestString", 10, 200, paint);
            canvas.drawCircle(60, 300, 50, paint);
            
            holder.unlockCanvasAndPost(canvas); // Canvas unlock
        }
        
        public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        }
        
        public void surfaceDestroyed(SurfaceHolder holder) {
        }
    }
}

参考　Drawableクラスを使用するとき

Drawable drawable= ContextCompat.getDrawable(getApplicationContext(), R.drawable.image);