我是android新手。我正在开展手势部分。我卡住了,无法找到在Android中检测其Zoom或Rotation Gesture(Two Finger)的方法。
case MotionEvent.ACTION_MOVE:
if(event.getPointerCount() == 2) {
float currentX = event.getX();
Log.v(GlobalVars.TAG, (currentX - lastX) + "");
lastX = currentX;
double currentAngle = getAngle(event.getX(), event.getY());
Log.v(GlobalVars.TAG, "Rotation Y::" + (startAngle - currentAngle));
if((startAngle - currentAngle) > 0 && mRotate.y > (-1 * 45) && ) {
mRotate.y -= 1.0;
} else if((startAngle - currentAngle) < 0 && mRotate.y < 45) {
mRotate.y += 1.0;
}
startAngle = currentAngle;
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
mOrigin.z *= detector.getScaleFactor(); // scale change since previous event
mOrigin.z = Math.max(MIN_ZOOM, Math.min(mOrigin.z, MAX_ZOOM)); //Max Zoom Value.
return true;
}
}
答案 0 :(得分:1)
您可以从指针移动方向检测它,如左,右或上,下。如果第一个指针向左或向下移动,第二个指针向右或向上移动,则表示用户正在尝试旋转图像。所以禁用那个时间的缩放事件。我检测旋转和缩放的代码是这样的。我希望它对你有所帮助。
private boolean isRotate(MotionEvent event){
int dx1 = (int) (event.getX(0) - lastEvent[0]);
int dy1 = (int) (event.getY(0) - lastEvent[2]);
int dx2 = (int) (event.getX(1) - lastEvent[1]);
int dy2 = (int) (event.getY(1) - lastEvent[3]);
Log.d("dx1 ", ""+ dx1);
Log.d("dx2 ", "" + dx2);
Log.d("dy1 ", "" + dy1);
Log.d("dy2 ", "" + dy2);
//pointer 1
if(Math.abs(dx1) > Math.abs(dy1) && Math.abs(dx2) > Math.abs(dy2)) {
if(dx1 >= 2.0 && dx2 <= -2.0){
Log.d("first pointer ", "right");
return true;
}
else if(dx1 <= -2.0 && dx2 >= 2.0){
Log.d("first pointer ", "left");
return true;
}
}
else {
if(dy1 >= 2.0 && dy2 <= -2.0){
Log.d("seccond pointer ", "top");
return true;
}
else if(dy1 <= -2.0 && dy2 >= 2.0){
Log.d("second pointer ", "bottom");
return true;
}
}
return false;
}
然后你可以在ACTION_MOVE上查看
if (mode == DRAG && !isZoomAndRotate) {
isZoomAndRotate = false;
view.setTranslationX((event.getX() - start.x) + view.getTranslationX());
view.setTranslationY((event.getY() - start.y) + view.getTranslationY());
} else if (mode == ZOOM && event.getPointerCount() == 2) {
isZoomAndRotate = true;
boolean isZoom = false;
if(!isRotate(event)){
float newDist = spacing(event);
if (newDist > 10f) {
float scale = newDist / oldDist * view.getScaleX();
view.setScaleX(scale);
view.setScaleY(scale);
isZoom = true;
}
}
else if(!isZoom){
newRot = rotation(event);
view.setRotation((float)(view.getRotation() + (newRot - d)));
}
}