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) {

}
});
posted @ 2017-02-28 11:53  lucktian  阅读(1190)  评论(0编辑  收藏  举报