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自定义ViewGroup 实现拖动跟快速滚动的效果
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效果： 1：子控件跟著手指移動? 2：快速撥動一下，根據撥動的速度 滑動過去? 3：拖過頭，放手后彈回去?
? ?但是用listView或者GridView又不好實現項目要求的其他效果..于是繼承viewGroup實現以上效果。?
? ?既然要獲取撥動速度，并以此滑動。首先想到了OnGestureListener 這個接口，實現這個接口并實現其onFling方法.?
? 還要控制拖動。重寫onTouchEvent方法，并在其中控制內容控件的拖動，反彈等效果?
這時候基本已經完成了。。。。測試了一下了，發現了一個問題，當手指點在viewGroup上?
進行 拖動是沒問題的，但是在子控件上就不行了，這是事件響應的問題 那么還要做如面的處?
理:實現onInterceptTouchEvent方法，判斷是拖動事件時 ，將事件傳遞下去。?
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[java] view plaincopyprint?
import?java.util.List;????import?android.content.Context;????import?android.graphics.Color;????import?android.util.Log;????import?android.view.GestureDetector;????import?android.view.MotionEvent;????import?android.view.View;????import?android.view.ViewConfiguration;????import?android.view.ViewGroup;????import?android.view.GestureDetector.OnGestureListener;????import?android.widget.Button;????import?android.widget.ImageView;????import?android.widget.Scroller;????import?android.widget.Toast;????import?android.widget.ImageView.ScaleType;????????public?class?MyViewGroup?extends?ViewGroup?implements?OnGestureListener?{????????????private?float?mLastMotionY;????private?GestureDetector?detector;????????int?move?=?0;????int?MAXMOVE?=?850;????private?Scroller?mScroller;????????int?up_excess_move?=?0;????int?down_excess_move?=?0;????private?final?static?int?TOUCH_STATE_REST?=?0;????????private?final?static?int?TOUCH_STATE_SCROLLING?=?1;????????private?int?mTouchSlop;????????private?int?mTouchState?=?TOUCH_STATE_REST;????????Context?mContext;????????????????????public?MyViewGroup(Context?context)?{????????????super(context);????????????mContext?=?context;????????????????????setBackgroundResource(R.drawable.pic);????????????mScroller?=?new?Scroller(context);????????????detector?=?new?GestureDetector(this);????????????????final?ViewConfiguration?configuration?=?ViewConfiguration.get(context);????????????????????mTouchSlop?=?configuration.getScaledTouchSlop();????????????????????????for?(int?i?=?0;?i?<?48;?i++)?{????????????????final?Button????MButton?=?new?Button(context);????????????????MButton.setText(""?+?(i?+?1));????????????????MButton.setOnClickListener(new?OnClickListener()?{????????????????????????????????????????public?void?onClick(View?v)?{????????????????????????????????????????????Toast.makeText(mContext,?MButton.getText(),?Toast.LENGTH_SHORT).show();?????????????????????}????????????????});????????????????addView(MButton);????????????}????????}????????????@Override????????public?void?computeScroll()?{????????????if?(mScroller.computeScrollOffset())?{????????????????????????????scrollTo(0,?mScroller.getCurrY());????????????????postInvalidate();????????????}????????}????????????@Override????????public?boolean?onInterceptTouchEvent(MotionEvent?ev)?{????????????final?int?action?=?ev.getAction();????????????????final?float?y?=?ev.getY();????????????switch?(ev.getAction())????????????{????????????case?MotionEvent.ACTION_DOWN:????????????????????mLastMotionY?=?y;????????????????mTouchState?=?mScroller.isFinished()???TOUCH_STATE_REST????????????????????????:?TOUCH_STATE_SCROLLING;????????????????break;????????????case?MotionEvent.ACTION_MOVE:????????????????final?int?yDiff?=?(int)?Math.abs(y?-?mLastMotionY);????????????????boolean?yMoved?=?yDiff?>?mTouchSlop;????????????????????????????if?(yMoved)?{????????????????????mTouchState?=?TOUCH_STATE_SCROLLING;????????????????}????????????????break;????????????case?MotionEvent.ACTION_UP:????????????????mTouchState?=?TOUCH_STATE_REST;????????????????break;????????????}????????????return?mTouchState?!=?TOUCH_STATE_REST;????????}????????????@Override????????public?boolean?onTouchEvent(MotionEvent?ev)?{????????????????????????????final?float?y?=?ev.getY();????????????switch?(ev.getAction())????????????{????????????case?MotionEvent.ACTION_DOWN:????????????????if?(!mScroller.isFinished())?{????????????????????mScroller.forceFinished(true);????????????????????move?=?mScroller.getFinalY();????????????????}????????????????mLastMotionY?=?y;????????????????break;????????????case?MotionEvent.ACTION_MOVE:????????????????if?(ev.getPointerCount()?==?1)?{????????????????????????????????????????????????????????int?deltaY?=?0;????????????????????deltaY?=?(int)?(mLastMotionY?-?y);????????????????????mLastMotionY?=?y;????????????????????Log.d("move",?""?+?move);????????????????????if?(deltaY?<?0)?{????????????????????????????????????????????????????????????????if?(up_excess_move?==?0)?{????????????????????????????if?(move?>?0)?{????????????????????????????????int?move_this?=?Math.max(-move,?deltaY);????????????????????????????????move?=?move?+?move_this;????????????????????????????????scrollBy(0,?move_this);????????????????????????????}?else?if?(move?==?0)?{????????????????????????????Log.d("down_excess_move",?""?+?down_excess_move);????????????????????????????????down_excess_move?=?down_excess_move?-?deltaY?/?2;????????????????????????????scrollBy(0,?deltaY?/?2);????????????????????????????}????????????????????????}?else?if?(up_excess_move?>?0)????????????????????{???????????????????????????????????????????????if?(up_excess_move?>=?(-deltaY))?{????????????????????????????????up_excess_move?=?up_excess_move?+?deltaY;????????????????????????????????scrollBy(0,?deltaY);????????????????????????????}?else?{????????????????????????????????????????????????????????up_excess_move?=?0;????????????????????????????????scrollBy(0,?-up_excess_move);???????????????????????????????????????????}????????????????????????}????????????????????}?else?if?(deltaY?>?0)?{????????????????????????????????????????????if?(down_excess_move?==?0)?{????????????????????????????if?(MAXMOVE?-?move?>?0)?{????????????????????????????????int?move_this?=?Math.min(MAXMOVE?-?move,?deltaY);????????????????????????????????move?=?move?+?move_this;????????????????????????????????scrollBy(0,?move_this);????????????????????????????}?else?if?(MAXMOVE?-?move?==?0)?{????????????????????????????????if?(up_excess_move?<=?100)?{????????????????????????????????????up_excess_move?=?up_excess_move?+?deltaY?/?2;????????????????????????????????????scrollBy(0,?deltaY?/?2);????????????????????????????????}????????????????????????????}????????????????????????}?else?if?(down_excess_move?>?0)?{????????????????????????????if?(down_excess_move?>=?deltaY)?{????????????????????????????????down_excess_move?=?down_excess_move?-?deltaY;????????????????????????????????scrollBy(0,?deltaY);????????????????????????????}?else?{????????????????????????????????down_excess_move?=?0;????????????????????????????????scrollBy(0,?down_excess_move);????????????????????????????}????????????????????????}????????????????????}???????????????????????}?????????????????break;????????????case?MotionEvent.ACTION_UP:?????????????????????????????????????if?(up_excess_move?>?0)?{????????????????????????????????????scrollBy(0,?-up_excess_move);????????????????????invalidate();????????????????????up_excess_move?=?0;????????????????}????????????????if?(down_excess_move?>?0)?{????????????????????????????????????scrollBy(0,?down_excess_move);????????????????????invalidate();????????????????????down_excess_move?=?0;????????????????}????????????????mTouchState?=?TOUCH_STATE_REST;????????????????break;????????????}????????????return?this.detector.onTouchEvent(ev);????????}????????????int?Fling_move?=?0;????????????public?boolean?onFling(MotionEvent?e1,?MotionEvent?e2,?float?velocityX,????????????????float?velocityY)?{?????????????????????Log.d("onFling",?"onFling");????????????if?(up_excess_move?==?0?&&?down_excess_move?==?0)?{????????????????????int?slow?=?-(int)?velocityY?*?3?/?4;????????????????mScroller.fling(0,?move,?0,?slow,?0,?0,?0,?MAXMOVE);????????????????move?=?mScroller.getFinalY();????????????????computeScroll();????????????}????????????return?false;????????}????????????public?boolean?onDown(MotionEvent?e)?{????????????????????return?true;????????}????????????public?boolean?onScroll(MotionEvent?e1,?MotionEvent?e2,?float?distanceX,????????????????float?distanceY)?{????????????return?false;????????}????????????public?void?onShowPress(MotionEvent?e)?{????????????????}????????????public?boolean?onSingleTapUp(MotionEvent?e)?{????????????????????return?false;????????}????????????public?void?onLongPress(MotionEvent?e)?{????????????????}????????????@Override????????protected?void?onLayout(boolean?changed,?int?l,?int?t,?int?r,?int?b)?{????????????????????int?childTop?=?0;????????????int?childLeft?=?0;????????????final?int?count?=?getChildCount();????????????for?(int?i?=?0;?i?<?count;?i++)?{????????????????final?View?child?=?getChildAt(i);????????????????if?(child.getVisibility()?!=?View.GONE)?{????????????????????child.setVisibility(View.VISIBLE);????????????????????child.measure(r?-?l,?b?-?t);????????????????????child????????????????????????????.layout(childLeft,?childTop,?childLeft?+?80,????????????????????????????????????childTop?+?80);????????????????????if?(childLeft?<?160)?{????????????????????????childLeft?+=?80;????????????????????}?else?{????????????????????????childLeft?=?0;????????????????????????childTop?+=?80;????????????????????}????????????????}????????????}????????}????????}???? ?
[java] view plaincopyprint?
import?android.content.Context;????import?android.view.View;????import?android.view.ViewGroup;????????public?class?Workspace?extends?ViewGroup?{????????????public?Workspace(Context?context)?{????????????super(context);????????????????????addView(new?MyViewGroup(context));????????}????????????@Override????????protected?void?onLayout(boolean?changed,?int?l,?int?t,?int?r,?int?b)?{????????????????????final?int?count?=?getChildCount();????????????for?(int?i?=?0;?i?<?count;?i++)?{????????????????final?View?child?=?getChildAt(i);????????????????child.measure(r?-?l,?b?-?t);????????????????child.layout(0,?0,?320,?480);????????????}????????}????????}???? ?
[java] view plaincopyprint?
import?android.app.Activity;????import?android.os.Bundle;????????public?class?MoveViewGroup?extends?Activity?{????????????@Override????????public?void?onCreate(Bundle?savedInstanceState)?{????????????super.onCreate(savedInstanceState);????????????setContentView(new?Workspace(this));????????????}????}???? http://blog.csdn.net/ztp800201/article/details/14057695
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