关于ListView的HeaderView

来源：互联网发布：淘宝开店必备编辑：程序博客网时间：2024/05/21 08:52

1. 可点击/不可点击

private void addHeaderView(){View headerView = this.mInflater.inflate(R.layout.XXX_header_info, this.listView, false);this.headerInfo = (TextView) headerView.findViewById(R.id.XXX_HeaderInfo);//this.listView.addHeaderView(headerView);//让HeaderView不可点击 this.listView.addHeaderView(headerView, null, false);this.headerInfo.setVisibility(View.GONE);}

2. HeaderView滑动到完全看不到之后隐藏

this.listView.setOnScrollListener(new OnScrollListener() {@Overridepublic void onScrollStateChanged(AbsListView view, int scrollState) {if(scrollState == SCROLL_STATE_IDLE && headerInfo.getVisibility() == View.VISIBLE && listView.getFirstVisiblePosition() > 0) {//listView.removeHeaderView(headerView);headerInfo.setVisibility(View.GONE);}}@Overridepublic void onScroll(AbsListView view, int firstVisibleItem,int visibleItemCount, int totalItemCount) {}});

如果刷新后需要显示HeaderView，再次设置可见即可：

private void setHeaderInfo(int num) {String text = String.format("关于“%s”，共%d条评论。", XXXXData.name, num);this.headerInfo.setText(text);this.headerInfo.setVisibility(View.VISIBLE);}

而不必在removeHeaderView之后再次add：

if(this.listView.getHeaderViewsCount() <= 0) {this.listView.addHeaderView(this.headerView, null, false);}

采用removeHeaderView()方法移除headerView的方法会出现显示问题：直接移除ListView的列表头会出现屏幕跳动，改为设置headerView的子视图不可见即可。

这里的headerInfo是headerView的子视图，直接设置headerView不可见的话，headerView是看不到了，但是仍然占用了listView视图的高度，只是显示为空白而已。下面是XXX_HeaderInfo.xml：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="wrap_content"        android:orientation="vertical" >    <TextView        android:id="@+id/XXX_HeaderInfo"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:gravity="center_vertical"        android:padding="9dp"        android:textColor="@color/text_color"        android:textSize="@dimen/title_text_size"         android:background="#fefee2"/></LinearLayout>

这里没有给根视图添加背景，而是把背景设置到了子视图TextView的背景上了。

直接add/remove headerView在某些机型上可能会出现问题，也可以通过往headerView里添加移除子视图headerInfo的方式来实现。

其他要注意的地方就是在给listView增加页眉、页脚的时机要在setAdapter之前，这是add的代码：

    /**     * Add a fixed view to appear at the top of the list. If addHeaderView is     * called more than once, the views will appear in the order they were     * added. Views added using this call can take focus if they want.     * <p>     * NOTE: Call this before calling setAdapter. This is so ListView can wrap     * the supplied cursor with one that will also account for header and footer     * views.     *     * @param v The view to add.     * @param data Data to associate with this view     * @param isSelectable whether the item is selectable     */    public void addHeaderView(View v, Object data, boolean isSelectable) {        if (mAdapter != null) {            throw new IllegalStateException(                    "Cannot add header view to list -- setAdapter has already been called.");        }        FixedViewInfo info = new FixedViewInfo();        info.view = v;        info.data = data;        info.isSelectable = isSelectable;        mHeaderViewInfos.add(info);    }

通过设置headerView不可见，并且remove页眉的方式，屏幕出现了跳动。刷新数据后设置可见、add页眉，也没有出错，如果只是通过原代码来解释似乎不通。

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