关于CoordinatorLayout和ListView滑动冲突的解决

来源：互联网发布：eia数据公布编辑：程序博客网时间：2024/06/05 06:40

最近项目中使用到了CoordinatorLayout这种布局方式,搭配RecycleView,实现起来比较简单,而且不用自己处理滑动事件,但是改为了ListView后发生了滑动冲突.

所以想到了以下解决方案:

1.使用事件分发,当ListView在Y轴滑动时,将事件交给CoordinatorLayout处理,无效!!!

2.取消ListView在Y轴的滑动,计算手指移动的距离,交给CoordinatorLayout来scroll,无效!!!

以上都不行,google了下,发现由于由于CoordinatorLayout实现NestedScrollingParent接口,RecycleView实现了NestedScrollingChild接口,所以就可以在NestedScrollingChildHelper的帮助下实现滑动联动,知道了原因这就简单了,让我们的LIstView实现NestedScrollingChild接口,查看下NestedScrollingChild接口的源码

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**
* This interface should be implemented by {@link android.view.View View} subclasses that wish
* to support dispatching nested scrolling operations to a cooperating parent
* {@link android.view.ViewGroup ViewGroup}.
*
* <p>Classes implementing this interface should create a final instance of a
* {@link NestedScrollingChildHelper} as a field and delegate any View methods to the
* <code>NestedScrollingChildHelper</code> methods of the same signature.</p>
*
* <p>Views invoking nested scrolling functionality should always do so from the relevant
* {@link ViewCompat}, {@link ViewGroupCompat} or {@link ViewParentCompat} compatibility
* shim static methods. This ensures interoperability with nested scrolling views on Android
* 5.0 Lollipop and newer.</p>
*/
public interface NestedScrollingChild {

** * This interface should be implemented by {@link android.view.View View} subclasses that wish * to support dispatching nested scrolling operations to a cooperating parent * {@link android.view.ViewGroup ViewGroup}. * * <p>Classes implementing this interface should create a final instance of a * {@link NestedScrollingChildHelper} as a field and delegate any View methods to the * <code>NestedScrollingChildHelper</code> methods of the same signature.</p> * * <p>Views invoking nested scrolling functionality should always do so from the relevant * {@link ViewCompat}, {@link ViewGroupCompat} or {@link ViewParentCompat} compatibility * shim static methods. This ensures interoperability with nested scrolling views on Android * 5.0 Lollipop and newer.</p> */public interface NestedScrollingChild {

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…………..

..............

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}

看到开头注释中这样一段话:

实现这个接口必须创建NestedScrollingChildHelper,并且将View的方法交给NestedScrollingChildHelper的同名方法来处理,所以我们就在自定义ListView中加入

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public class MyListView extends ListView implements NestedScrollingChild{
private final NestedScrollingChildHelper mScrollingChildHelper;
public DPListView(Context context, AttributeSet attrs) {
super(context, attrs);
mScrollingChildHelper = new NestedScrollingChildHelper(this);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
setNestedScrollingEnabled(true);
}
}
@Override
public void setNestedScrollingEnabled(boolean enabled) {
mScrollingChildHelper.setNestedScrollingEnabled(enabled);
}
@Override
public boolean isNestedScrollingEnabled() {
return mScrollingChildHelper.isNestedScrollingEnabled();
}
@Override
public boolean startNestedScroll(int axes) {
return mScrollingChildHelper.startNestedScroll(axes);
}
@Override
public void stopNestedScroll() {
mScrollingChildHelper.stopNestedScroll();
}
@Override
public boolean hasNestedScrollingParent() {
return mScrollingChildHelper.hasNestedScrollingParent();
}
@Override
public boolean dispatchNestedScroll(int dxConsumed, int dyConsumed, int dxUnconsumed,
int dyUnconsumed, int[] offsetInWindow) {
return mScrollingChildHelper.dispatchNestedScroll(dxConsumed, dyConsumed,
dxUnconsumed, dyUnconsumed, offsetInWindow);
}
@Override
public boolean dispatchNestedPreScroll(int dx, int dy, int[] consumed, int[] offsetInWindow) {
return mScrollingChildHelper.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow);
}
@Override
public boolean dispatchNestedFling(float velocityX, float velocityY, boolean consumed) {
return mScrollingChildHelper.dispatchNestedFling(velocityX, velocityY, consumed);
}
@Override
public boolean dispatchNestedPreFling(float velocityX, float velocityY) {
return mScrollingChildHelper.dispatchNestedPreFling(velocityX, velocityY);
}
}

public class MyListView extends ListView implements NestedScrollingChild{private final NestedScrollingChildHelper mScrollingChildHelper;public DPListView(Context context, AttributeSet attrs) {        super(context, attrs);        mScrollingChildHelper = new NestedScrollingChildHelper(this);        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {            setNestedScrollingEnabled(true);        }    }    @Override    public void setNestedScrollingEnabled(boolean enabled) {        mScrollingChildHelper.setNestedScrollingEnabled(enabled);    }    @Override    public boolean isNestedScrollingEnabled() {        return mScrollingChildHelper.isNestedScrollingEnabled();    }    @Override    public boolean startNestedScroll(int axes) {        return mScrollingChildHelper.startNestedScroll(axes);    }    @Override    public void stopNestedScroll() {        mScrollingChildHelper.stopNestedScroll();    }    @Override    public boolean hasNestedScrollingParent() {        return mScrollingChildHelper.hasNestedScrollingParent();    }    @Override    public boolean dispatchNestedScroll(int dxConsumed, int dyConsumed, int dxUnconsumed,                                        int dyUnconsumed, int[] offsetInWindow) {        return mScrollingChildHelper.dispatchNestedScroll(dxConsumed, dyConsumed,                dxUnconsumed, dyUnconsumed, offsetInWindow);    }    @Override    public boolean dispatchNestedPreScroll(int dx, int dy, int[] consumed, int[] offsetInWindow) {        return mScrollingChildHelper.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow);    }    @Override    public boolean dispatchNestedFling(float velocityX, float velocityY, boolean consumed) {        return mScrollingChildHelper.dispatchNestedFling(velocityX, velocityY, consumed);    }    @Override    public boolean dispatchNestedPreFling(float velocityX, float velocityY) {        return mScrollingChildHelper.dispatchNestedPreFling(velocityX, velocityY);    }}

最后在xml布局文件中,在MyListView外层嵌套一层NestedScrollView即可

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<android.support.v4.widget.NestedScrollView
android:layout_width=“match_parent”
android:layout_height=“match_parent”
android:fillViewport=“true”
app:layout_behavior=“@string/appbar_scrolling_view_behavior”>
<com.dipaitv.widget.DPListView
android:id=“@+id/listview”
android:layout_width=“match_parent”
android:layout_height=“wrap_content”>
</com.dipaitv.widget.DPListView>
</android.support.v4.widget.NestedScrollView>

<android.support.v4.widget.NestedScrollView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:fillViewport="true"                    app:layout_behavior="@string/appbar_scrolling_view_behavior">                <com.dipaitv.widget.DPListView                    android:id="@+id/listview"                    android:layout_width="match_parent"                    android:layout_height="wrap_content">                </com.dipaitv.widget.DPListView>                </android.support.v4.widget.NestedScrollView>

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