CoordinatorLayout协同布局在一般只结合RecyclerView和NestedScrollView使用，如果我使用ListView没有效果的。但是，由于业务原因使用ListView，有需要实现协同的效果怎么办？
其实分析RecyclerView和NestedScrollView的源码可以知道，他们都实现了一个接口NestedScrollingChild，所以我们可以自定义ListView，实现NestedScrollingChild接口就好。当然除此外，google还提供了一个API
mListView.setNestedScrollingEnabled(true),就可以使用。当然，这2种方法只有在Android5.0以上才有效果。
下面就滑动ListView，让fab悬浮按钮滑动出现和滑动消失为例：
这里需要自定义一个Behavior类，这个类将作用于fab悬浮按钮，也就是在fab悬浮按钮中使用这个属性，如下：
app:layout_behavior="www.weshared.listviewandcoor.QuickReturnFooterBehavior"具体代码如下：
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="www.weshared.listviewandcoor.MainActivity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<include layout="@layout/content_main" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
app:layout_behavior="www.weshared.listviewandcoor.QuickReturnFooterBehavior"
android:layout_margin="@dimen/fab_margin"
android:src="@android:drawable/ic_dialog_email" />
</android.support.design.widget.CoordinatorLayout>content_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="www.weshared.listviewandcoor.MainActivity"
tools:showIn="@layout/activity_main">
<ListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</RelativeLayout>list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="60dp">
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/tv_item"
android:layout_width="match_parent"
android:layout_height="60dp"
android:gravity="center"
android:text="ee">
</TextView>
</RelativeLayout>MainActivity文件中
public class MainActivity extends AppCompatActivity {
private ArrayList<String> mdatas = new ArrayList();
private ListView mListView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
initView();
}
private void initView() {
mListView = (ListView) findViewById(R.id.lv);
//API21以上才有效果----第二种方式，比较简便
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
mListView.setNestedScrollingEnabled(true);
}
initData();
mListView.setAdapter(new MyListAdapter(mdatas));
}
private void initData() {
for(int i=0;i<30;i++){
mdatas.add("---------"+i+"-----------");
}
}
}MyListAdapter文件就省略吧
自定义ListView实现NestedScrollingChild接口,看代码也可以知道，其实发挥作用的就是setNestedScrollingEnabled(true)这个方法
public class NestedScrollingListView extends ListView implements NestedScrollingChild {
private NestedScrollingChildHelper mNestedScrollingChildHelper;
public NestedScrollingListView(final Context context) {
super(context);
initHelper();
}
public NestedScrollingListView(final Context context, final AttributeSet attrs) {
super(context, attrs);
initHelper();
}
public NestedScrollingListView(final Context context, final AttributeSet attrs, final int defStyleAttr) {
super(context, attrs, defStyleAttr);
initHelper();
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public NestedScrollingListView(final Context context, final AttributeSet attrs, final int defStyleAttr, final int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
initHelper();
}
private void initHelper() {
mNestedScrollingChildHelper = new NestedScrollingChildHelper(this);
setNestedScrollingEnabled(true);
}
@Override
public void setNestedScrollingEnabled(final boolean enabled) {
mNestedScrollingChildHelper.setNestedScrollingEnabled(enabled);
}
@Override
public boolean isNestedScrollingEnabled() {
return mNestedScrollingChildHelper.isNestedScrollingEnabled();
}
@Override
public boolean startNestedScroll(final int axes) {
return mNestedScrollingChildHelper.startNestedScroll(axes);
}
@Override
public void stopNestedScroll() {
mNestedScrollingChildHelper.stopNestedScroll();
}
@Override
public boolean hasNestedScrollingParent() {
return mNestedScrollingChildHelper.hasNestedScrollingParent();
}
@Override
public boolean dispatchNestedScroll(final int dxConsumed, final int dyConsumed, final int dxUnconsumed, final int dyUnconsumed, final int[] offsetInWindow) {
return mNestedScrollingChildHelper.dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, offsetInWindow);
}
@Override
public boolean dispatchNestedPreScroll(final int dx, final int dy, final int[] consumed, final int[] offsetInWindow) {
return mNestedScrollingChildHelper.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow);
}
@Override
public boolean dispatchNestedFling(final float velocityX, final float velocityY, final boolean consumed) {
return mNestedScrollingChildHelper.dispatchNestedFling(velocityX, velocityY, consumed);
}
@Override
public boolean dispatchNestedPreFling(final float velocityX, final float velocityY) {
return mNestedScrollingChildHelper.dispatchNestedPreFling(velocityX, velocityY);
}
}
最重要的一个类Behavior的实现类
public class QuickReturnFooterBehavior extends CoordinatorLayout.Behavior<View> {
private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();
private int mDySinceDirectionChange;
private boolean mIsShowing;
private boolean mIsHiding;
public QuickReturnFooterBehavior(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, View child, View directTargetChild, View target, int nestedScrollAxes) {
return (nestedScrollAxes & ViewCompat.SCROLL_AXIS_VERTICAL) != 0;
}
@Override
public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, View child, View target, int dx, int dy, int[] consumed) {
if (dy > 0 && mDySinceDirectionChange < 0
|| dy < 0 && mDySinceDirectionChange > 0) {
// We detected a direction change- cancel existing animations and reset our cumulative delta Y
child.animate().cancel();
mDySinceDirectionChange = 0;
}
mDySinceDirectionChange += dy;
if (mDySinceDirectionChange > child.getHeight()
&& child.getVisibility() == View.VISIBLE
&& !mIsHiding) {
hide(child);
} else if (mDySinceDirectionChange < 0
&& child.getVisibility() == View.GONE
&& !mIsShowing) {
show(child);
}
}
/**
* Hide the quick return view.
*
* Animates hiding the view, with the view sliding down and out of the screen.
* After the view has disappeared, its visibility will change to GONE.
*
* @param view The quick return view
*/
private void hide(final View view) {
mIsHiding = true;
ViewPropertyAnimator animator = view.animate()
.translationY(view.getHeight())
.setInterpolator(INTERPOLATOR)
.setDuration(200);
animator.setListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animator) {}
@Override
public void onAnimationEnd(Animator animator) {
// Prevent drawing the View after it is gone
mIsHiding = false;
view.setVisibility(View.GONE);
}
@Override
public void onAnimationCancel(Animator animator) {
// Canceling a hide should show the view
mIsHiding = false;
if (!mIsShowing) {
show(view);
}
}
@Override
public void onAnimationRepeat(Animator animator) {}
});
animator.start();
}
/**
* Show the quick return view.
*
* Animates showing the view, with the view sliding up from the bottom of the screen.
* After the view has reappeared, its visibility will change to VISIBLE.
*
* @param view The quick return view
*/
private void show(final View view) {
mIsShowing = true;
ViewPropertyAnimator animator = view.animate()
.translationY(0)
.setInterpolator(INTERPOLATOR)
.setDuration(200);
animator.setListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animator) {
view.setVisibility(View.VISIBLE);
}
@Override
public void onAnimationEnd(Animator animator) {
mIsShowing = false;
}
@Override
public void onAnimationCancel(Animator animator) {
// Canceling a show should hide the view
mIsShowing = false;
if (!mIsHiding) {
hide(view);
}
}
@Override
public void onAnimationRepeat(Animator animator) {}
});
animator.start();
}
}
时间： 2024-10-09 10:17:59