android 自定义滚动上下回弹scollView

来源：互联网发布：上海高通待遇知乎编辑：程序博客网时间：2024/05/21 19:31

这是一个自定义view，在xml布局中用这个view嵌套要使之可以上下回弹的view，

就能实现布局可以滚动上下回弹了，自定义view代码如下：

package com.loopfire.meitaotao.view.scrollView;import android.content.Context;import android.graphics.Rect;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import android.view.animation.Animation;import android.view.animation.Animation.AnimationListener;import android.view.animation.TranslateAnimation;import android.widget.ScrollView;/** * 上下回弹 scollView *  * @author Administrator *  */public class MyScrollView extends ScrollView {private View inner;private float y;private Rect normal = new Rect();private boolean animationFinish = true;public MyScrollView(Context context) {super(context);}public MyScrollView(Context context, AttributeSet attrs) {super(context, attrs);}@Overrideprotected void onFinishInflate() {if (getChildCount() > 0) {inner = getChildAt(0);}}@Overridepublic boolean onInterceptTouchEvent(MotionEvent ev) {return super.onInterceptTouchEvent(ev);}@Overridepublic boolean onTouchEvent(MotionEvent ev) {if (inner == null) {return super.onTouchEvent(ev);} else {commOnTouchEvent(ev);}return super.onTouchEvent(ev);}private void commOnTouchEvent(MotionEvent ev) {if (animationFinish) {int action = ev.getAction();switch (action) {case MotionEvent.ACTION_DOWN:// System.out.println("ACTION_DOWN");y = ev.getY();super.onTouchEvent(ev);break;case MotionEvent.ACTION_UP:// System.out.println("ACTION_UP");y = 0;if (isNeedAnimation()) {animation();}super.onTouchEvent(ev);break;case MotionEvent.ACTION_MOVE:// System.out.println("ACTION_MOVE");final float preY = y == 0 ? ev.getY() : y;float nowY = ev.getY();int deltaY = (int) (preY - nowY);// 滚动// scrollBy(0, deltaY);y = nowY;// 当滚动到最上或者最下时就不会再滚动，这时移动布局if (isNeedMove()) {if (normal.isEmpty()) {// 保存正常的布局位置normal.set(inner.getLeft(), inner.getTop(), inner.getRight(), inner.getBottom());}// 移动布局inner.layout(inner.getLeft(), inner.getTop() - deltaY / 2, inner.getRight(), inner.getBottom() - deltaY / 2);} else {super.onTouchEvent(ev);}break;default:break;}}}// 开启动画移动private void animation() {// 开启移动动画TranslateAnimation ta = new TranslateAnimation(0, 0, 0, normal.top - inner.getTop());ta.setDuration(200);ta.setAnimationListener(new AnimationListener() {@Overridepublic void onAnimationStart(Animation animation) {animationFinish = false;}@Overridepublic void onAnimationRepeat(Animation animation) {}@Overridepublic void onAnimationEnd(Animation animation) {inner.clearAnimation();// 设置回到正常的布局位置inner.layout(normal.left, normal.top, normal.right, normal.bottom);normal.setEmpty();animationFinish = true;}});inner.startAnimation(ta);}// 是否需要开启动画private boolean isNeedAnimation() {return !normal.isEmpty();}// 是否需要移动布局private boolean isNeedMove() {int offset = inner.getMeasuredHeight() - getHeight();int scrollY = getScrollY();if (scrollY == 0 || scrollY == offset) {return true;}return false;}}

在xml中使用如下：

 <com.loopfire.meitaotao.view.scrollView.MyScrollView>                        <TextView                            style="@style/form_left_text_style"                            android:layout_width="wrap_content"                            android:layout_height="wrap_content"                            android:layout_marginLeft="@dimen/text_margin_left2"                            android:text="@string/about" />                    </com.loopfire.meitaotao.view.scrollView.MyScrollView>

那么包含的这个textview可以上下滚动并且回弹了

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