仿IOS效果-带弹簧动画的ListView

背景介绍

最近项目打算做一个界面,类似于dayone首页的界面效果,dayone 是一款付费应用,目前只有IOS端。作为一个资深懒惰的程序员，奉行的宗旨是绝对不重复造一个轮子。于是乎，去网上找一大堆开源项目，发现没有找到合适的，然后，只能硬着头皮自己来了。先看看效果：

其实写起来也比较简单，就是控制ListView的头部和底部的高度就可以了, 如果用RecycleView实现起来也是一样,只是RecycleView添加头和尾巴稍微麻烦一点,处理点击事件也不是很方便,所以就基于ListView去实现了。

实现的代码，我已经上传到github上了。

使用方法

github地址: https://github.com/yll2wcf/YLListView 可以帮我点个star啊~

使用方法

 compile 'com.a520wcf.yllistview:YLListView:1.0.1'

使用介绍:

布局:
布局注意一个小细节android:layout_height 最好是match_parent, 否则ListView每次滑动的时候都有可能需要重新计算条目高度,比较耗费CPU;

    <com.a520wcf.yllistview.YLListViewandroid:divider="@android:color/transparent"android:id="@+id/listView"android:layout_width="match_parent"android:layout_height="match_parent"/>

代码:

   private YLListView listView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);listView = (YLListView) findViewById(R.id.listView);// 不添加也有默认的头和底View topView=View.inflate(this,R.layout.top,null);listView.addHeaderView(topView);View bottomView=new View(getApplicationContext());listView.addFooterView(bottomView);// 顶部和底部也可以固定最终的高度 不固定就使用布局本身的高度listView.setFinalBottomHeight(100);listView.setFinalTopHeight(100);listView.setAdapter(new DemoAdapter());//YLListView默认有头和底  处理点击事件位置注意减去listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> parent, View view, int position, long id) {position=position-listView.getHeaderViewsCount();}});}

源码介绍

其实这个项目里面只有一个类,大家不需要依赖,直接把这个类复制到项目中就可以了,来看看源码:

package com.a520wcf.yllistview;import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.view.animation.DecelerateInterpolator;
import android.widget.AbsListView;
import android.widget.ListView;
import android.widget.Scroller;/*** 邮箱 yll@520wcf.com* Created by yull on 12/17.*/
public class YLListView extends ListView implements AbsListView.OnScrollListener {private Scroller mScroller; // used for scroll backprivate float mLastY = -1;private int mScrollBack;private final static int SCROLLBACK_HEADER = 0;private final static int SCROLLBACK_FOOTER = 1;private final static int SCROLL_DURATION = 400; // scroll back durationprivate final static float OFFSET_RADIO = 1.8f;// total list items, used to detect is at the bottom of ListView.private int mTotalItemCount;private View mHeaderView;  // 顶部图片private View mFooterView;  // 底部图片private int finalTopHeight;private int finalBottomHeight;public YLListView(Context context) {super(context);initWithContext(context);}public YLListView(Context context, AttributeSet attrs) {super(context, attrs);initWithContext(context);}public YLListView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);initWithContext(context);}private void initWithContext(Context context) {mScroller = new Scroller(context, new DecelerateInterpolator());super.setOnScrollListener(this);this.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {@Overridepublic void onGlobalLayout() {if(mHeaderView==null){View view=new View(getContext());addHeaderView(view);}if(mFooterView==null){View view=new View(getContext());addFooterView(view);}getViewTreeObserver().removeGlobalOnLayoutListener(this);}});}@Overridepublic boolean onTouchEvent(MotionEvent ev) {if (mLastY == -1) {mLastY = ev.getRawY();}switch (ev.getAction()) {case MotionEvent.ACTION_DOWN:mLastY = ev.getRawY();break;case MotionEvent.ACTION_MOVE:final float deltaY = ev.getRawY() - mLastY;mLastY = ev.getRawY();if (getFirstVisiblePosition() == 0 && (mHeaderView.getHeight() > finalTopHeight || deltaY > 0)&& mHeaderView.getTop() >= 0) {// the first item is showing, header has shown or pull down.updateHeaderHeight(deltaY / OFFSET_RADIO);} else if (getLastVisiblePosition() == mTotalItemCount - 1&& (getFootHeight() >finalBottomHeight || deltaY < 0)) {updateFooterHeight(-deltaY / OFFSET_RADIO);}break;default:mLastY = -1; // resetif (getFirstVisiblePosition() == 0 && getHeaderHeight() > finalTopHeight) {resetHeaderHeight();}if (getLastVisiblePosition() == mTotalItemCount - 1 ){if(getFootHeight() > finalBottomHeight) {resetFooterHeight();}}break;}return super.onTouchEvent(ev);}/*** 重置底部高度*/private void resetFooterHeight() {int bottomHeight = getFootHeight();if (bottomHeight > finalBottomHeight) {mScrollBack = SCROLLBACK_FOOTER;mScroller.startScroll(0, bottomHeight, 0, -bottomHeight+finalBottomHeight,SCROLL_DURATION);invalidate();}}// 计算滑动  当invalidate()后 系统会自动调用@Overridepublic void computeScroll() {if (mScroller.computeScrollOffset()) {if (mScrollBack == SCROLLBACK_HEADER) {setHeaderHeight(mScroller.getCurrY());} else {setFooterViewHeight(mScroller.getCurrY());}postInvalidate();}super.computeScroll();}// 设置顶部高度private void setHeaderHeight(int height) {LayoutParams layoutParams = (LayoutParams) mHeaderView.getLayoutParams();layoutParams.height = height;mHeaderView.setLayoutParams(layoutParams);}// 设置底部高度private void setFooterViewHeight(int height) {LayoutParams layoutParams =(LayoutParams) mFooterView.getLayoutParams();layoutParams.height =height;mFooterView.setLayoutParams(layoutParams);}// 获取顶部高度public int getHeaderHeight() {AbsListView.LayoutParams layoutParams =(AbsListView.LayoutParams) mHeaderView.getLayoutParams();return layoutParams.height;}// 获取底部高度public int getFootHeight() {AbsListView.LayoutParams layoutParams =(AbsListView.LayoutParams) mFooterView.getLayoutParams();return layoutParams.height;}private void resetHeaderHeight() {int height = getHeaderHeight();if (height == 0) // not visible.return;mScrollBack = SCROLLBACK_HEADER;mScroller.startScroll(0, height, 0, finalTopHeight - height,SCROLL_DURATION);invalidate();}/*** 设置顶部高度  如果不设置高度,默认就是布局本身的高度* @param height 顶部高度*/public void setFinalTopHeight(int height) {this.finalTopHeight = height;}/*** 设置底部高度  如果不设置高度,默认就是布局本身的高度* @param height 底部高度*/public void setFinalBottomHeight(int height){this.finalBottomHeight=height;}@Overridepublic void addHeaderView(View v) {mHeaderView = v;super.addHeaderView(mHeaderView);mHeaderView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {@Overridepublic void onGlobalLayout() {if(finalTopHeight==0) {finalTopHeight = mHeaderView.getMeasuredHeight();}setHeaderHeight(finalTopHeight);getViewTreeObserver().removeGlobalOnLayoutListener(this);}});}@Overridepublic void addFooterView(View v) {mFooterView = v;super.addFooterView(mFooterView);mFooterView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {@Overridepublic void onGlobalLayout() {if(finalBottomHeight==0) {finalBottomHeight = mFooterView.getMeasuredHeight();}setFooterViewHeight(finalBottomHeight);getViewTreeObserver().removeGlobalOnLayoutListener(this);}});}private OnScrollListener mScrollListener; // user's scroll listener@Overridepublic void setOnScrollListener(OnScrollListener l) {mScrollListener = l;}@Overridepublic void onScrollStateChanged(AbsListView view, int scrollState) {if (mScrollListener != null) {mScrollListener.onScrollStateChanged(view, scrollState);}}@Overridepublic void onScroll(AbsListView view, int firstVisibleItem,int visibleItemCount, int totalItemCount) {// send to user's listenermTotalItemCount = totalItemCount;if (mScrollListener != null) {mScrollListener.onScroll(view, firstVisibleItem, visibleItemCount,totalItemCount);}}private void updateHeaderHeight(float delta) {setHeaderHeight((int) (getHeaderHeight()+delta));setSelection(0); // scroll to top each time}private void updateFooterHeight(float delta) {setFooterViewHeight((int) (getFootHeight()+delta));}
}

转载于:https://www.cnblogs.com/hehe520/p/6329905.html