我尝试了教程http://www.vogella.com/tutorials/AndroidTouch/article.html中给出的多点触控颜色点代码
我想要触摸一个点,当我移动手指时,一个点shuold保持在那里而另一个应该移动 . 就像操纵杆一样 .
因此弹出点会出现并停留在那里,直到我抬起手指,如果我移动手指,则应移动另一个相同颜色的点
我试过这段代码
public class MultitouchView extends View {
private static final int SIZE = 150;
float xx;
float yy;
float[] abcisa;
float[] ordinate;
private SparseArray<PointF> mActivePointers;
private Paint mPaint;
private int[] colors = { Color.BLUE, Color.GREEN, Color.MAGENTA,
Color.BLACK, Color.CYAN, Color.GRAY, Color.RED, Color.DKGRAY,
Color.LTGRAY, Color.YELLOW };
private Paint textPaint;
public MultitouchView(Context context, AttributeSet attrs) {
super(context, attrs);
initView();
}
private void initView() {
mActivePointers = new SparseArray<PointF>();
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
// set painter color to a color you like
mPaint.setColor(Color.BLUE);
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
textPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
textPaint.setTextSize(20);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// get pointer index from the event object
int pointerIndex = event.getActionIndex();
// get pointer ID
int pointerId = event.getPointerId(pointerIndex);
// get masked (not specific to a pointer) action
int maskedAction = event.getActionMasked();
switch (maskedAction) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_DOWN: {
// We have a new pointer. Lets add it to the list of pointers
PointF f = new PointF();
xx = f.x = event.getX(pointerIndex);
yy = f.y = event.getY(pointerIndex);
canvas.drawCircle(xx, yy, SIZE, mPaint);
mActivePointers.put(pointerId, f);
break;
}
case MotionEvent.ACTION_MOVE: { // a pointer was moved
for (int size = event.getPointerCount(), i = 0; i < size; i++) {
PointF point = mActivePointers.get(event.getPointerId(i));
if (point != null) {
point.x = event.getX(i);
point.y = event.getY(i);
}
}
break;
}
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
case MotionEvent.ACTION_CANCEL: {
mActivePointers.remove(pointerId);
break;
}
}
invalidate();
return true;
}
@Override
protected void onDraw(Canvas canvas) {
// draw all pointers
for (int size = mActivePointers.size(), i = 0; i < size; i++) {
PointF point = mActivePointers.valueAt(i);
if (point != null)
mPaint.setColor(colors[i % 9]);
canvas.drawCircle(xx, yy, SIZE, mPaint);
canvas.drawCircle(point.x, point.y, SIZE, mPaint);
}
canvas.drawText("Total pointers: " + mActivePointers.size(), 10, 40 , textPaint);
}
}
我还尝试将xx和yy存储在一个数组中作为xx [pointerID]并在canvas.drawCircle上访问它但应用程序崩溃了
它的代码是这样的
public class MultitouchView extends View {
private static final int SIZE = 150;
float[] xx;
float[] yy;
private SparseArray<PointF> mActivePointers;
private Paint mPaint;
private int[] colors = { Color.BLUE, Color.GREEN, Color.MAGENTA,
Color.BLACK, Color.CYAN, Color.GRAY, Color.RED, Color.DKGRAY,
Color.LTGRAY, Color.YELLOW };
private Paint textPaint;
public MultitouchView(Context context, AttributeSet attrs) {
super(context, attrs);
initView();
}
private void initView() {
mActivePointers = new SparseArray<PointF>();
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
// set painter color to a color you like
mPaint.setColor(Color.BLUE);
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
textPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
textPaint.setTextSize(20);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// get pointer index from the event object
int pointerIndex = event.getActionIndex();
// get pointer ID
int pointerId = event.getPointerId(pointerIndex);
// get masked (not specific to a pointer) action
int maskedAction = event.getActionMasked();
switch (maskedAction) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_DOWN: {
// We have a new pointer. Lets add it to the list of pointers
PointF f = new PointF();
xx[pointerId] = f.x = event.getX(pointerIndex);
yy[pointerId] = f.y = event.getY(pointerIndex);
mActivePointers.put(pointerId, f);
break;
}
case MotionEvent.ACTION_MOVE: { // a pointer was moved
for (int size = event.getPointerCount(), i = 0; i < size; i++) {
PointF point = mActivePointers.get(event.getPointerId(i));
if (point != null) {
point.x = event.getX(i);
point.y = event.getY(i);
}
}
break;
}
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
case MotionEvent.ACTION_CANCEL: {
mActivePointers.remove(pointerId);
break;
}
}
invalidate();
return true;
}
@Override
protected void onDraw(Canvas canvas) {
// draw all pointers
for (int size = mActivePointers.size(), i = 0; i < size; i++) {
PointF point = mActivePointers.valueAt(i);
if (point != null)
mPaint.setColor(colors[i % 9]);
canvas.drawCircle(xx[i], yy[i], SIZE, mPaint);
canvas.drawCircle(point.x, point.y, SIZE, mPaint);
}
canvas.drawText("Total pointers: " + mActivePointers.size(), 10, 40 , textPaint);
}
}
请帮忙 .
崩溃日志
06-01 16:48:42.781 10922-10922 / com.example.nimishmaravikd.colourmtouch E / AndroidRuntime:FATAL EXCEPTION:main进程:com.example.nimishmaravikd.colourmtouch,PID:10922 java.lang.NullPointerException:尝试写在android.view.ViewGroup.DispatchTransformedTouchEvent(ViewGroup.java: 2554)在android.view.View.View上的android.view.View.View.St上的android.view.View.View的一个android.view.View.View.St上的android.view.View.View的一个android.view.View.View的一个android.view.View.St上发现了android.view.View.View . 位于android.view.View.View.StartEvent(ViewGroup.java:2598)的android.view.View.St.EvatchTouchEvent(ViewGroup.java:2598)的android.view.View.St.EvatchTouchEvent(ViewGroup.java:2554) (ViewGroup.java:2198)在com.android.internal.policy.PhoneWind来自com.android的android.app.Activity.dispatchTouchEvent(Activity.java:2832)的com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1739)的$ DecorView.superDispatchTouchEvent(PhoneWindow.java:2405) .internal.policy.PhoneWindow $ DecorView.dispatchTouchEvent(PhoneWindow.java:2366)at android.view.View.dispatchPointerEvent(View.java:9543)at android.view.ViewRootImpl $ ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4619)at at android.view.ViewRootImpl $ ViewPostImeInputStage.onProcess(ViewRootImpl.java:4480)android.view.ViewRootImpl $ InputStage.deliver(ViewRootImpl.java:4010)at android.view.ViewRootImpl $ InputStage.onDeliverToNext(ViewRootImpl.java:4063)在android.view.ViewRootImpl $ InputStage.forward(ViewRootImpl.java:4029)android.view.ViewRootImpl $ AsyncInputStage.forward(ViewRootImpl.java:4155)at android.view.ViewRootImpl $ InputStage.apply(ViewRootImpl.java:4037) )在andro的android.view.ViewRootImpl $ AsyncInputStage.apply(ViewRootImpl.java:4212) id.view.ViewRootImpl $ InputStage.deliver(ViewRootImpl.java:4010)at android.view.ViewRootImpl $ InputStage.onDeliverToNext(ViewRootImpl.java:4063)at android.view.ViewRootImpl $ InputStage.forward(ViewRootImpl.java:4029)在android.view.ViewRootImpl $ InputStage.apply(ViewRootImpl.java:4037)的android.view.ViewRootImpl $ InputStage.deliver(ViewRootImpl.java:4010)at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6397)at at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:6371)在Android.view.View.View上的android.view.ViewRootImpl $ WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:6576)的android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6318) .inputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)位于android.os.MessageQueue.next(MessageQueue.java:324)的android.os.MessageQueue.nativePollOnce(Native Method),位于android.os.Looper.loop(Looper.java) :135)在android.app.ActivityThread.main(ActivityThread.java:5582)java.lang.reflect.Method.invoke(N) com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:726)at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)06-01 16:48:ative Method) 42.791 10922-10933 / com.example.nimishmaravikd.colourmtouch I / ActivityThreadEui:schedulePauseActivity com.example.nimishmaravikd.colourmtouch.MainActivity finished = true userLeaving = false configChanges = 0 dontReport = false
1 回答
不要改变所有的代码: - 根据我的理解,你想要移动相同的颜色 . 我只是检查相同的颜色移动 .
试试这个!!