使用MotionEvent在视图上同时移动两个位图

我使用下面的类（Android中的简单2D图形）在我的视图上创建了两个位图，并且漫游以实现该位图可以独立移动。 我为此调用了motionevent方法。

目前的问题，我不明白为什么在下面的代码中只有一个对象正在移动。 例如，使用此代码，只移动“not”位图，我想独立于彼此移动两个位图。

scenrio：我可以使用我的两个fingures，每个对象一个，独立移动位图。 但我不知道如何实现这一目标。

public class TouchView extends View { private Drawable cross; private Rect crossBounds = null; private Drawable not; private Rect notBounds = null; private int x1, y1, x2, y2 ; boolean flag = true; private void intialize () { int w1 = cross.getIntrinsicWidth(); int h1 = cross.getIntrinsicHeight(); x1 = 100; y1 = 100; crossBounds = new Rect(x1-w1/2, y1-w1/2, x1+w1/2, y1+h1/2); int w = not.getIntrinsicWidth(); int h = not.getIntrinsicHeight(); x2 = 300; y2 = 300; notBounds = new Rect(x2-w/2, y2-w/2, x2+w/2, y2+h/2); } public TouchView(Context context) { super(context); // Get a representation of the image Resources resources = context.getResources(); cross = (Drawable) resources.getDrawable(R.drawable.cross); not = (Drawable) resources.getDrawable(R.drawable.not); } @Override public boolean onTouchEvent(MotionEvent event) { Log.i("TouchView.onTouchEvent", "event = " + event); if(event.getAction() == MotionEvent.ACTION_DOWN || event.getAction() == MotionEvent.ACTION_MOVE) { int touchCounter = event.getPointerCount(); if (touchCounter ==2 && getHeight ()==y1){ int w = cross.getIntrinsicWidth(); int h = cross.getIntrinsicHeight(); x1 = (int) event.getX(); crossBounds = new Rect(x1-w/2, y1-w/2, x1+w/2, y1+h/2); } else { int w1 = not.getIntrinsicWidth(); int h1 = not.getIntrinsicHeight(); x2 = (int) event.getX(); notBounds = new Rect(x2-w1/2, y2-w1/2, x2+w1/2, y2+h1/2); } // Request the system to redraw the view (call onDraw at // some point in the future) // From a non-UI thread, call postInvalidate instead invalidate(); return true; } return false; } @Override protected void onDraw(Canvas canvas) { Log.i("TouchView.onDraw", ""); // Background Paint bgPaint = new Paint(); bgPaint.setColor(Color.WHITE); canvas.drawPaint(bgPaint); if (flag == true){ intialize (); cross.setBounds(crossBounds); cross.draw(canvas); not.setBounds(notBounds); not.draw(canvas); flag=false; } if(crossBounds != null) { cross.setBounds(crossBounds); cross.draw(canvas); not.setBounds(notBounds); not.draw(canvas); } } } 

Answer 1

 public class SimpleDrag extends View { private final int INVALID_INDEX = -1; private final int mTotalItems = 5; private ArrayList mItemsCollection; private ArrayList mActiveDragPoints; private ArrayList mActiveRects; private Paint mPaint; /** * @param context * @return of type SimpleDrag * Constructor function * @since Feb 19, 2013 * @author rajeshcp */ public SimpleDrag(Context context) { super(context); init(); } /** * @param context * @param attrs * @return of type SimpleDrag * Constructor function * @since Feb 19, 2013 * @author rajeshcp */ public SimpleDrag(Context context, AttributeSet attrs) { super(context, attrs); init(); } /** * @param context * @param attrs * @param defStyle * @return of type SimpleDrag * Constructor function * @since Feb 19, 2013 * @author rajeshcp */ public SimpleDrag(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(); } /* (non-Javadoc) * @see android.view.View#onDraw(android.graphics.Canvas) * @since Feb 19, 2013 * @author rajeshcp */ @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); canvas.drawColor(Color.BLUE, PorterDuff.Mode.CLEAR); for( Rect rect : mItemsCollection) { canvas.drawRect(rect, mPaint); } } /** * @param of type null * @return of type null * function which will initialize the view * @since Feb 20, 2013 * @author rajeshcp */ private void init() { mActiveRects = new ArrayList(mTotalItems); mActiveDragPoints = new ArrayList(mTotalItems); mItemsCollection = new ArrayList(); for( int i = 0; i < mTotalItems; i++) { Rect rect = new Rect(i * 100, i * 100, (i + 1) * 100, (i + 1) * 100); mItemsCollection.add(rect); } mPaint = new Paint(Paint.FILTER_BITMAP_FLAG | Paint.DITHER_FLAG | Paint.ANTI_ALIAS_FLAG); mPaint.setColor(Color.RED); } /* (non-Javadoc) * @see android.view.View#onTouchEvent(android.view.MotionEvent) * @since Feb 19, 2013 * @author rajeshcp */ @Override public boolean onTouchEvent(MotionEvent event) { final int action = event.getActionMasked(); final int pointer = event.getActionIndex(); switch (action) { case MotionEvent.ACTION_DOWN : Point touchDown = new Point((int)event.getX(), (int)event.getY()); lookForIntersection(touchDown); break; case MotionEvent.ACTION_UP : case MotionEvent.ACTION_CANCEL : mActiveDragPoints.removeAll(mActiveDragPoints); mActiveRects.removeAll(mActiveRects); break; case MotionEvent.ACTION_MOVE : int count = 0; for(Rect rect : mActiveRects) { Point curretPoint = new Point((int)event.getX(count), (int)event.getY(count)); moveRect(curretPoint, mActiveDragPoints.get(count), rect); count++; } Log.d(getClass().getName(), "Active Rects" + mActiveRects.size()); Log.d(getClass().getName(), "Active Points" + mActiveDragPoints.size()); invalidate(); break; case MotionEvent.ACTION_POINTER_DOWN : touchDown = new Point((int)event.getX(pointer), (int)event.getY(pointer)); lookForIntersection(touchDown); //Log.d(getClass().getName(), "ACTION_POINTER_DOWN" + pointer); break; case MotionEvent.ACTION_POINTER_UP : int index = getIntersectionRectIndex(new Point((int)event.getX(pointer), (int)event.getY(pointer))); if( index != INVALID_INDEX ) { Rect rect = mItemsCollection.get(index); mActiveDragPoints.remove(mActiveRects.indexOf(rect)); mActiveRects.remove(rect); } break; default: break; } return true; } /** * @param touchDown of type Point * @return of type null * function which will find the * intersecting rect and add to the * active collection * @since Feb 20, 2013 * @author rajeshcp */ private void lookForIntersection(Point touchDown) { final int index = getIntersectionRectIndex(touchDown); if( index != INVALID_INDEX ) { final Rect rect = mItemsCollection.get(index); if( mActiveRects.indexOf(rect) == INVALID_INDEX ) { mActiveDragPoints.add(touchDown); mActiveRects.add(mItemsCollection.get(index)); } } Log.d(getClass().getName(), "Active Rects" + mActiveRects.size()); Log.d(getClass().getName(), "Active Points" + mActiveDragPoints.size()); } /** * @param point of type Point * @return of type int * function which will return the index of * the rect contaning the given point * @since Feb 20, 2013 * @author rajeshcp */ private int getIntersectionRectIndex(final Point point) { int index = INVALID_INDEX; for(Rect rect : mItemsCollection) { if( rect.contains(point.x, point.y) ) { index = mItemsCollection.indexOf(rect); break; } } return index; } /** * @param currentPoint of type Point * @param prevPoint of type Point * @param rect of type Rect * @return of type null * function which will move the change the * bounds of teh rect * @since Feb 20, 2013 * @author rajeshcp */ private void moveRect(Point currentPoint, Point prevPoint, final Rect rect) { int xMoved = currentPoint.x - prevPoint.x; int yMoved = currentPoint.y - prevPoint.y; rect.set(rect.left + xMoved, rect.top + yMoved, rect.right + xMoved, rect.bottom + yMoved); mActiveDragPoints.set(mActiveDragPoints.indexOf(prevPoint), currentPoint); } } 

希望这是你想要的，没有经过多少测试，但基本上这对我有用，即使你可以通过改变mTotalItems来增加nof项目。 希望这会有所帮助。