简单的多点触摸实例
androidi的多点触摸其实还有不少的缺陷 我在测试中只能用两点不知道是我写的不对 还是 本身就有错误
其实单点和多点没啥却别关键就在
MotionEvent.ACTION_POINTER_UP:
MotionEvent.ACTION_POINTER_DOWN:
这些点上的实现
public class Touch extends Activity implements OnTouchListener {
?? private static final String TAG = "Touch";
?? // These matrices will be used to move and zoom image
?? Matrix matrix = new Matrix();
?? Matrix savedMatrix = new Matrix();
?? // We can be in one of these 3 states
?? static final int NONE = 0;
?? static final int DRAG = 1;
?? static final int ZOOM = 2;
?? int mode = NONE;
?? // Remember some things for zooming
?? PointF start = new PointF();
?? PointF mid = new PointF();
?? float oldDist = 1f;
?? @Override
?? public void onCreate(Bundle savedInstanceState) {
????? super.onCreate(savedInstanceState);
????? setContentView(R.layout.main);
????? ImageView view = (ImageView) findViewById(R.id.imageView);
????? view.setOnTouchListener(this);
?? }
?? @Override
?? public boolean onTouch(View v, MotionEvent event) {
????? ImageView view = (ImageView) v;
????? // Dump touch event to log
????? dumpEvent(event);
????? // Handle touch events here...
????? switch (event.getAction() & MotionEvent.ACTION_MASK) {
????? case MotionEvent.ACTION_DOWN:
???????? savedMatrix.set(matrix);
???????? start.set(event.getX(), event.getY());
???????? Log.d(TAG, "mode=DRAG");
???????? mode = DRAG;
???????? break;
????? case MotionEvent.ACTION_POINTER_DOWN:
???????? oldDist = spacing(event);
???????? Log.d(TAG, "oldDist=" + oldDist);
???????? if (oldDist > 10f) {
??????????? savedMatrix.set(matrix);
??????????? midPoint(mid, event);
??????????? mode = ZOOM;
??????????? Log.d(TAG, "mode=ZOOM");
???????? }
???????? break;
????? case MotionEvent.ACTION_UP:
????? case MotionEvent.ACTION_POINTER_UP:
???????? mode = NONE;
???????? Log.d(TAG, "mode=NONE");
???????? break;
????? case MotionEvent.ACTION_MOVE:
???????? if (mode == DRAG) {
??????????? // ...
??????????? matrix.set(savedMatrix);
??????????? matrix.postTranslate(event.getX() - start.x,
????????????????? event.getY() - start.y);
???????? }
???????? else if (mode == ZOOM) {
??????????? float newDist = spacing(event);
??????????? Log.d(TAG, "newDist=" + newDist);
??????????? if (newDist > 10f) {
?????????????? matrix.set(savedMatrix);
?????????????? float scale = newDist / oldDist;
?????????????? matrix.postScale(scale, scale, mid.x, mid.y);
??????????? }
???????? }
???????? break;
????? }
????? view.setImageMatrix(matrix);
????? return true; // indicate event was handled
?? }
?? /** Show an event in the LogCat view, for debugging */
?? private void dumpEvent(MotionEvent event) {
????? String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
??????????? "POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
????? StringBuilder sb = new StringBuilder();
????? int action = event.getAction();
????? int actionCode = action & MotionEvent.ACTION_MASK;
????? sb.append("event ACTION_").append(names[actionCode]);
????? if (actionCode == MotionEvent.ACTION_POINTER_DOWN
??????????? || actionCode == MotionEvent.ACTION_POINTER_UP) {
???????? sb.append("(pid ").append(
?????????????? action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
???????? sb.append(")");
????? }
????? sb.append("[");
????? for (int i = 0; i < event.getPointerCount(); i++) {
???????? sb.append("#").append(i);
???????? sb.append("(pid ").append(event.getPointerId(i));
???????? sb.append(")=").append((int) event.getX(i));
???????? sb.append(",").append((int) event.getY(i));
???????? if (i + 1 < event.getPointerCount())
??????????? sb.append(";");
????? }
????? sb.append("]");
????? Log.d(TAG, sb.toString());
?? }
?? /** Determine the space between the first two fingers */
?? private float spacing(MotionEvent event) {
????? float x = event.getX(0) - event.getX(1);
????? float y = event.getY(0) - event.getY(1);
????? return FloatMath.sqrt(x * x + y * y);
?? }
?? /** Calculate the mid point of the first two fingers */
?? private void midPoint(PointF point, MotionEvent event) {
????? float x = event.getX(0) + event.getX(1);
????? float y = event.getY(0) + event.getY(1);
????? point.set(x / 2, y / 2);
?? }
}
?
1 楼 lrc_1986 2011-06-20 高手~就是高手~ 2 楼 琼露露 2011-09-23 米有仔细看,好像挺复杂的哈