撕衣服案例

public class MainActivity extends AppCompatActivity {
    private ImageView iv;

    @SuppressLint("ClickableViewAccessibility")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        iv = findViewById(R.id.iv);
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.pre19);
        final Bitmap bitmap1 = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());
        Paint paint = new Paint();
        final Canvas canvas = new Canvas(bitmap1);
        canvas.drawBitmap(bitmap, new Matrix(), paint);
        iv.setImageBitmap(bitmap1);
        iv.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                int action = event.getAction();
                switch (action) {
                    case MotionEvent.ACTION_MOVE:
                        for (int i = 0; i < 20; i++) {
                            for (int j = 0; j < 20; j++) {
                                try {
                                    bitmap1.setPixel((int) event.getX() + i, (int) event.getY() + j, Color.TRANSPARENT);
                                } catch (Exception e) {
                                    e.printStackTrace();
                                }
                            }
                        }
                        iv.setImageBitmap(bitmap1);
                }
                return true;
            }
        });
    }
}