我想在同一个画布上移动多个位图。使用下面的代码我可以在屏幕上触摸时移动一个位图但是，我无法识别位图上的触摸事件，因此我无法移动特定的位图。
public class DrawTopologyView extends View {
Paint paint = new Paint();
Bitmap zed_bitMap, lamp_on_bitmap, fan_on_bitmap, ac_on_bitmap;
int START_X = 5;
int START_Y = 5;
float x = 500-24,y=START_Y;
public DrawTopologyView(Context context) {
super(context);
zed_bitMap = BitmapFactory.decodeResource(context.getResources(),
R.drawable.zed);
lamp_on_bitmap = BitmapFactory.decodeResource(context.getResources(),
R.drawable.lamp_on);
fan_on_bitmap = BitmapFactory.decodeResource(context.getResources(),
R.drawable.fan_on);
ac_on_bitmap = BitmapFactory.decodeResource(context.getResources(),
R.drawable.ac_on);
}
@Override
public void onDraw(Canvas canvas) {
int CENTER_X = canvas.getWidth() / 2 - 24;
int CENTER_Y = canvas.getHeight() / 2 - zed_bitMap.getHeight();
int FULL_WIDTH = canvas.getWidth();
int FULL_HEIGHT = canvas.getHeight();
canvas.drawBitmap(zed_bitMap, CENTER_X, CENTER_Y, paint);
paint.setStrokeWidth(3);
paint.setPathEffect(new DashPathEffect(new float[] { 5, 5, 5, 5 }, 0));
canvas.drawBitmap(ac_on_bitmap, START_X, START_Y, paint);
canvas.drawLine(START_X + 48, START_Y + 48, CENTER_X + 10,
CENTER_Y + 10, paint);
canvas.drawLine(250, START_Y + 48, CENTER_X + 10, CENTER_Y + 10, paint);
canvas.drawBitmap(lamp_on_bitmap, 250 - 24, START_Y, paint);
canvas.drawLine(500, START_Y + 48, CENTER_X + 10, CENTER_Y + 10, paint);
canvas.drawBitmap(fan_on_bitmap, x,y, paint);
// canvas.drawLine(FULL_WIDTH-40,FULL_HEIGHT-120,CENTER_X+30,CENTER_Y+30,
// paint);
// canvas.drawBitmap(light_off_bitmap, FULL_WIDTH-60-24,FULL_HEIGHT-130,
// paint);
}
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN: {
}
break;
case MotionEvent.ACTION_MOVE: {
x = (int) event.getX();
y = (int) event.getY();
invalidate();
}
break;
case MotionEvent.ACTION_UP:
x = (int) event.getX();
y = (int) event.getY();
Log.d(APPConstant.LOG_TAG, ".................." + x + "......" + y);
Toast.makeText(getContext(), ".................." + x + "......" + y,Toast.LENGTH_SHORT).show();
invalidate();
break;
}
return true;
}
}
答案 0 :(得分：2)
public class SimpleDrag extends View {
private final int INVALID_INDEX = -1;
private final int mTotalItems = 5;
private ArrayList<Rect> mItemsCollection;
private ArrayList<Point> mActiveDragPoints;
private ArrayList<Rect> 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<Rect>(mTotalItems);
mActiveDragPoints = new ArrayList<Point>(mTotalItems);
mItemsCollection = new ArrayList<Rect>();
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);
}
}
这允许您一次选择多个位图。这种情况我只使用矩形，你可以用位图填充这个矩形。