使用LinearLayout实现ListView,解决ListView和ScrollView滚动冲突

在项目中，我们常常会遇到一个ScrollView里面会嵌套ListView的情况，但往往你会发现，ListView和ScrollView的滚动时间会有冲突问题，造成ListView不能完全显示。虽然网上有给出解决方案，但事实上并不好用，并不完美。

public void setListViewHeightBasedOnChildren(ListView listView) {

// 获取ListView对应的Adapter

ListAdapter listAdapter = listView.getAdapter();

if (listAdapter == null) {

return;

}

int totalHeight = 0;

for (int i = 0; i < listAdapter.getCount(); i++) { // listAdapter.getCount()返回数据项的数目

View listItem = listAdapter.getView(i, null, listView);

listItem.measure(0, 0); // 计算子项View 的宽高

totalHeight += listItem.getMeasuredHeight(); // 统计所有子项的总高度

}

ViewGroup.LayoutParams params = listView.getLayoutParams();

params.height = totalHeight
    + (listView.getDividerHeight() * (listAdapter.getCount() - 1));

// listView.getDividerHeight()获取子项间分隔符占用的高度

// params.height最后得到整个ListView完整显示需要的高度

listView.setLayoutParams(params);

}

因此，为了彻底解决问题，就需要我们另辟途径了，我们使用 LinearLayout 绑定 Adapter的方法来代替ListView

将 adapter 里面的 view 全部加入 LinearLayout 并设置回调监听，添加DataSetObserver监听adapter 的改变。

public class LinearLayoutForListView extends LinearLayout {
    private Adapter mAdapter;
    private OnItemClickListener  mOnItemClickListener;
    private SparseArray<View> mViewHolders;
    private AdapterDataSetObserver mDataSetObserver;

    public OnItemClickListener getOnItemClickListener() {
        return mOnItemClickListener;
    }
    public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
        mOnItemClickListener = onItemClickListener;
    }

    public LinearLayoutForListView(Context context) {
        super(context);
    }

    public LinearLayoutForListView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public LinearLayoutForListView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public void setAdapter(Adapter adapter) {
        this.mAdapter = adapter;
        bindLinearLayout();
    }
    /**  绑定布局 */
    private void bindLinearLayout() {
        if (mAdapter == null) {
            return;
        }
        setOrientation(LinearLayout.VERTICAL);
        int count = mAdapter.getCount();
        this.removeAllViews();
        mViewHolders = new SparseArray<View>(count);
        for (int i = 0; i < count; i++) {
            final View v = mAdapter.getView(i, null, null);
            final int tmp = i;
            final Object obj = mAdapter.getItem(i);
            mViewHolders.put(i,v);
            // view 点击事件触发时回调我们自己的接口
            v.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    if (mOnItemClickListener != null) {
                        mOnItemClickListener.onItemClicked(v, obj, tmp);
                    }
                }
            });
            addView(v);
        }
    }

    /**
     *
     * 回调接口
     */
    public interface OnItemClickListener {
        /**
         * @param v  点击的 view
         * @param obj  点击的 view 所绑定的对象
         * @param position  点击位置的 index
         */
        public void onItemClicked(View v, Object obj, int position);
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        if(mAdapter != null && mDataSetObserver == null){
            mDataSetObserver = new AdapterDataSetObserver();
            mAdapter.registerDataSetObserver(mDataSetObserver);
        }
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        if(mAdapter != null && mDataSetObserver != null){
            mAdapter.unregisterDataSetObserver(mDataSetObserver);
        }
    }

    private class AdapterDataSetObserver extends DataSetObserver {
        @Override
        public void onChanged() {
            if(mAdapter!=null){
                final int count = mAdapter.getCount();
                for (int i = 0; i < count; i++){
                    mAdapter.getView(i,mViewHolders.get(i,null),null);
                }
                requestLayout();
            }
        }
    }
}

调用

list.setAdapter(madapter);
list.setOnItemClickListener(new LinearLayoutForListView.OnItemClickListener() {
    @Override
    public void onItemClicked(View v, Object obj, int position) {

    }
});