有这样一个ListView,要求在屏幕底部有一个筛选排序的浮动框：
1、手指下拉隐藏，上滑显示 ；
2、如果没做任何操作，2S之后，要自动显示；
3、滑动到最底部，始终显示。
首先看其效果图：
实现上述效果，其实现原理如下：
1、在屏幕顶部固定一个BottomView，XML布局最好使用RelativeLayout(底部的BottomView并不是 ListView的footView，这个是和footView独立的，想想为什么？)
2、然后自定义ListView控件，监听onTouchEvent事件，主要是监听手指下滑和上滑事件，同时实现onScrollListener,监听是否滑动到最底部和最顶部
3、 ListView监听事件中，控制bottomView的显示和隐藏，所以ListView提供一个接口，设置底部bootomView的内容，然后获之后，就可以对bottomView进行控制，同时加上动画效果。
接下来看是如何的具体实现这种效果：
1。底部BottomView的内容如下，这个XML文件的内容是自定义的，根据各项目的内容需求来定义的，我例子中bottom_view.xml:
<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/button_layout"
android:layout_width="fill_parent"
android:layout_height="50dp"
android:background="#cbcbcb"
android:gravity="center_vertical"
android:orientation="horizontal" >
<Button android:layout_height="40dp"
android:layout_width="wrap_content"
android:layout_weight="1"
android:text="价格" />
<Button android:layout_height="40dp"
android:layout_width="wrap_content"
android:layout_weight="1"
android:text="好评" />
<Button android:layout_height="40dp"
android:layout_width="wrap_content"
android:layout_weight="1"
android:text="筛选" />
</LinearLayout>
2、main.xml如下
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<com.example.BottomFloatListView.BottomFloatListView
android:id="@+id/listView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:fadingEdge="none"
/>
<include
android:id="@+id/bottombar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
layout="@layout/bottom_view"
>
</include>
</RelativeLayout>
3、自定义ListView控件BottomFloatListView
package com.example.BottomFloatListView;
import android.content.Context;
import android.os.Handler;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.OvershootInterpolator;
import android.view.animation.TranslateAnimation;
import android.widget.*;
import android.widget.AbsListView.OnScrollListener;
/**
* 底部View自动隐藏和消失listview(其他ListView可以继承该类，如CtripBottomRefreshListView类等)
**/
public class BottomFloatListView extends ListView implements OnScrollListener {
public View mBottomBar;
private int mCurrentScrollState;
private boolean bIsMoved = false;
private boolean bIsDown = false;
private int mDeltaY;
private float mMotionY;
private int oldFirstVisibleItem = 0;
private Handler mHandler = new Handler();
private static final String TAG = "BottomFloatListView";
public BottomFloatListView(Context context) {
this(context, null);
super.setOnScrollListener(this);
}
public BottomFloatListView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
super.setOnScrollListener(this);
}
public BottomFloatListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
super.setOnScrollListener(this);
}
@Override
public void setAdapter(ListAdapter adapter) {
super.setAdapter(adapter);
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
showBottomViewOnBottom(visibleItemCount, totalItemCount, firstVisibleItem);
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
hideBottomViewOnScrollStateChanged(view, scrollState);
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
float y = ev.getY();
float x = ev.getX();
Log.d("FloatListView", "onTouchEvent" + "" + x + "" + y);
int action = ev.getAction() & MotionEvent.ACTION_MASK;
switch (action) {
case MotionEvent.ACTION_DOWN:
action_down(y);
break;
case MotionEvent.ACTION_MOVE:
mDeltaY = (int) (y - mMotionY);
bIsMoved = true;
//移动的时候，要移除掉显示bottomView的消息
mHandler.removeCallbacks(showBottomBarRunnable);
//补齐action_down事件，因为有的时候，action_down 事件没有执行
action_down(y);
break;
case MotionEvent.ACTION_UP:
bIsMoved = false;
bIsDown = false;
if (!bIsMoved && !bIsDown) {
// 如果屏幕上什么没做，则过2s之后要显示bottomView
mHandler.postDelayed(showBottomBarRunnable, 2000);
}
if (mDeltaY < 0) { //下滑影藏
hideBottomBar();
} else { //上滑显示
showBottomBar();
}
bIsMoved = false;
break;
}
return super.onTouchEvent(ev);
}
private void action_down(float y){
mMotionY = y;
bIsDown = true;
Log.d(TAG, "action down execed");
mHandler.removeCallbacks(showBottomBarRunnable);
}
/**
* 滑动到顶部时，要隐藏bottomView
* @param view
* @param scrollState
*/
private void hideBottomViewOnScrollStateChanged(AbsListView view, int scrollState) {
mCurrentScrollState = scrollState;
if(view!=null){
if (view.getFirstVisiblePosition() == 0 && scrollState == SCROLL_STATE_IDLE) {
hideBottomBar();
Log.d(TAG, "hide bottom view");
}
}
}
/**
* 显示底部浮动栏
*/
public void showBottomBar() {
if (mBottomBar != null && mBottomBar.getVisibility() == View.GONE) {
mBottomBar.setVisibility(View.INVISIBLE);
Animation translateAnimation = new TranslateAnimation(mBottomBar.getLeft(), mBottomBar.getLeft(),30, 0);
translateAnimation.setDuration(300);
translateAnimation.setInterpolator(new OvershootInterpolator(0.6f));
mBottomBar.startAnimation(translateAnimation);
translateAnimation.setAnimationListener(new Animation.AnimationListener() {
@Override
public void onAnimationStart(Animation animation) {
}
@Override
public void onAnimationRepeat(Animation animation) {
}
@Override
public void onAnimationEnd(Animation animation) {
mBottomBar.setVisibility(View.VISIBLE);
}
});
}
}
/**
* 隐藏浮动底部栏
*/
private void hideBottomBar() {
if (mBottomBar != null && mBottomBar.getVisibility() == View.VISIBLE) {
Animation translateAnimation = new TranslateAnimation(mBottomBar.getLeft(), mBottomBar.getLeft(), 0, 30);
translateAnimation.setDuration(300);
translateAnimation.setInterpolator(new OvershootInterpolator(0.6f));
mBottomBar.startAnimation(translateAnimation);
translateAnimation.setAnimationListener(new Animation.AnimationListener() {
@Override
public void onAnimationStart(Animation animation) {
}
@Override
public void onAnimationRepeat(Animation animation) {
}
@Override
public void onAnimationEnd(Animation animation) {
mBottomBar.setVisibility(View.GONE);
}
});
}
}
/**
* 滑动到底部时直接显示bottomView
* @param visibleItemCount
* @param totalItemCount
* @param firstVisibleItem
*/
private void showBottomViewOnBottom(int visibleItemCount, int totalItemCount, int firstVisibleItem) {
Log.d(TAG, "visible bottem item count:" + "firstVisibleItem:" + firstVisibleItem + "oldFirstVisibleItem:" + oldFirstVisibleItem + mBottomBar);
if(getLastVisiblePosition() == totalItemCount -1 && mCurrentScrollState != SCROLL_STATE_IDLE){
showBottomBar();
}
}
private Runnable showBottomBarRunnable = new Runnable() {
@Override
public void run() {
showBottomBar();
}
};
/**
* 将需要隐藏显示的view传入
*
* @param bottomBar
*/
public void setBottomBar(ViewGroup bottomBar) {
this.mBottomBar = bottomBar;
}
}
4、主界面测试的Activity，MainActivity代码如下
public class MainActivity extends Activity {
private BottomFloatListView mBottomFloatListView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mBottomFloatListView = (BottomFloatListView)findViewById(R.id.listView) ;
mBottomFloatListView.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_expandable_list_item_1,getData()));
ViewGroup bottomView = (ViewGroup)findViewById(R.id.bottombar) ;
mBottomFloatListView.setBottomBar(bottomView);
}
private List<String> getData(){
List<String> data = new ArrayList<String>();
for(int i = 0; i <100; i++) {
data.add("测试数据" + i);
}
return data;
}
}
ViewGroup bottomView = (ViewGroup)findViewById(R.id.bottombar) ; mBottomFloatListView.setBottomBar(bottomView);
将底部的bottomView传入到ListView中，就可以让ListView具有底部View自动隐藏和消失的功能。
