廢話不多說(shuō),具體代碼如下所示:
public class MyScrollView extends ScrollView { private View childView; public MyScrollView(Context context) { super(context); } public MyScrollView(Context context, AttributeSet attrs) { super(context, attrs); } public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); }// @Override// protected void onLayout(boolean changed, int l, int t, int r, int b) {// super.onLayout(changed, l, t, r, b);// } //獲取子視圖 @Override protected void onFinishInflate() { super.onFinishInflate(); if (getChildCount() > 0) { childView = getChildAt(0); } } private int lastY;//上一次y軸方向操作的坐標(biāo)位置 private Rect normal = new Rect();//用于記錄臨界狀態(tài)的左、上、右、下 private boolean isFinishAnimation = true;//是否動(dòng)畫結(jié)束 private int lastX, downX, downY; //攔截:實(shí)現(xiàn)父視圖對(duì)子視圖的攔截 //是否攔截成功,取決于方法的返回值。返回值true:攔截成功。反之,攔截失敗 @Override public boolean onInterceptTouchEvent(MotionEvent ev) { boolean isIntercept = false; int eventX = (int) ev.getX(); int eventY = (int) ev.getY(); switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: lastX = downX = eventX; lastY = downY = eventY; break; case MotionEvent.ACTION_MOVE: //獲取水平和垂直方向的移動(dòng)距離 int absX = Math.abs(eventX - downX); int absY = Math.abs(eventY - downY); if(absY > absX && absY >= UIUtils.dp2px(10)){ isIntercept = true;//執(zhí)行攔截 } lastX = eventX; lastY = eventY; break; } return isIntercept; } @Override public boolean onTouchEvent(MotionEvent ev) { if (childView == null || !isFinishAnimation) { return super.onTouchEvent(ev); } int eventY = (int) ev.getY();//獲取當(dāng)前的y軸坐標(biāo) switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: lastY = eventY; break; case MotionEvent.ACTION_MOVE: int dy = eventY - lastY;//微小的移動(dòng)量 if (isNeedMove()) { if (normal.isEmpty()) { //記錄了childView的臨界狀態(tài)的左、上、右、下 normal.set(childView.getLeft(), childView.getTop(), childView.getRight(), childView.getBottom()); } //重新布局 childView.layout(childView.getLeft(), childView.getTop() + dy / 2, childView.getRight(), childView.getBottom() + dy / 2); } lastY = eventY;//重新賦值 break; case MotionEvent.ACTION_UP: if (isNeedAnimation()) { //使用平移動(dòng)畫 int translateY = childView.getBottom() - normal.bottom; TranslateAnimation translateAnimation = new TranslateAnimation(0, 0, 0, -translateY); translateAnimation.setDuration(200);// translateAnimation.setFillAfter(true);//停留在最終位置上 translateAnimation.setAnimationListener(new Animation.AnimationListener() { @Override public void onAnimationStart(Animation animation) { isFinishAnimation = false; } @Override public void onAnimationEnd(Animation animation) { isFinishAnimation = true; childView.clearAnimation();//清除動(dòng)畫 //重新布局 childView.layout(normal.left, normal.top, normal.right, normal.bottom); //清除normal的數(shù)據(jù) normal.setEmpty(); } @Override public void onAnimationRepeat(Animation animation) { } }); //啟動(dòng)動(dòng)畫 childView.startAnimation(translateAnimation); } break; } return super.onTouchEvent(ev); } //判斷是否需要執(zhí)行平移動(dòng)畫 private boolean isNeedAnimation() { return !normal.isEmpty(); } private boolean isNeedMove() { int childMeasuredHeight = childView.getMeasuredHeight();//獲取子視圖的高度 int scrollViewMeasuredHeight = this.getMeasuredHeight();//獲取布局的高度 Log.e("TAG", "childMeasuredHeight = " + childMeasuredHeight); Log.e("TAG", "scrollViewMeasuredHeight = " + scrollViewMeasuredHeight); int dy = childMeasuredHeight - scrollViewMeasuredHeight;//dy >= 0 int scrollY = this.getScrollY();//獲取用戶在y軸方向上的偏移量 (上 + 下 -) if (scrollY <= 0 || scrollY >= dy) { return true;//按照我們自定義的MyScrollView的方式處理 } //其他處在臨界范圍內(nèi)的,返回false。即表示,仍按照ScrollView的方式處理 return false; }}以上所述是小編給大家介紹的Android界面上拉下拉的回彈效果實(shí)例代碼,希望對(duì)大家有所幫助,如果大家有任何疑問(wèn)請(qǐng)給我留言,小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)武林網(wǎng)網(wǎng)站的支持!
新聞熱點(diǎn)
疑難解答
圖片精選