NestedScrollView嵌套ListView出现问题以及解决方法

Posted 2022-05-03 隔壁小王66

在使用CoordinatorLayout和AppBarLayout实现嵌套滑动的时候，出现listview没有嵌套滑动；

看布局：

 <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.xiaodou.android.app.moshare.view.widget.MyListView
                android:id="@+id/lv_course_list"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@drawable/bg_course_list"
                android:divider="@color/divide_line"
                android:dividerHeight="@dimen/view_space_0.5" />
        </android.support.v4.widget.NestedScrollView>

这里面需要自定义listview实现NestedScrollingChild接口

public class MyListView extends ListView implements NestedScrollingChild 

    private final NestedScrollingChildHelper mScrollingChildHelper;

    public MyListView(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);
    
   

由于AppBarLayout折叠后在滑动NestedScrollView时与listview冲突，导致listview滑动延时，需要手指触摸listview一段时间才行，解决方法在自定义listview中重写onMeasure方法

@Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) 
        //测量的大小由一个32位的数字表示，前两位表示测量模式，后30位表示大小，这里需要右移两位才能拿到测量的大小
        int heightSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);
        super.onMeasure(widthMeasureSpec, heightSpec);