Android - 单击后保持 ListView 的项目突出显示 [英] Android - Keep ListView's item highlighted once one has been clicked

问题描述

所以我有一个带有 2 个 ListView 小部件的活动，当您在第一个小部件中选择一个值时，第二个小部件将填充与第一个 ListView 中的选择相关的值>.这个机制可以正常工作，但现在我希望用户选择保持突出显示.我已经阅读了大量与该主题相关的问题，似乎有无数种方法可以实现这一点，但是在尝试了大约 4-5 个 em 后，我仍然无法让它工作.

So I have an activity with 2 ListView widgets, when you select a value in the first one, the second is populated with values related to the selection in the first ListView. This mechanic works without a problem, but now I want the user choices to stay highlighted. I've read a good ammount of question related to this topic and it seems there is a myriad of ways one can accomplish this but after trying about 4-5 of em' I still can't get it to work.

我已经使用 android:listSelector="#CCCCCC" XML 属性在第二个 ListView 上工作，但这似乎被清除一次 OnItemClickListener 被引入到混合中(就像我在我的第一个 ListView 上使用的一样).

I've got it working on the second ListView using the android:listSelector="#CCCCCC" XML Attribute, but this seems to be wiped clean once a OnItemClickListener is introduced into the mix (like the one I use on my first ListView).

到目前为止，这是我所拥有的:

Custom OnItemClickListener 我发现浏览关于这个主题的各种答案(稍微修改它以便它加载我的信息第二个 ListView):

Custom OnItemClickListener I found browsing various answer regarding this topic (slightly modified it in order for it to load my info the second ListView):

private class ItemHighlighterListener implements OnItemClickListener {

    private View oldSelection = null;

    public void clearSelection() {
        if(oldSelection != null) {
            oldSelection.setBackgroundColor(android.R.color.transparent);
        }
    }

    public void onItemClick(AdapterView<?> parent, View view, int pos, long id) {
        clearSelection();
        oldSelection = view;
        view.setBackgroundDrawable(view.getContext().getResources().getDrawable(R.drawable.list_selector));
        loadClubs(mXMLPortalOptions.getRegion(pos).getId());
        mClubList.setAdapter(new ArrayAdapter<String>(getApplicationContext(), R.layout.list_item_white, mClubs));
    }
}

这是我的 list_selector.xml 文件:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_selected="true"><shape>
            <solid android:color="#CCCCCC" />
        </shape></item>

    <item android:state_selected="false"><shape>
            <solid android:color="#FFFFFF" />
        </shape></item>

</selector>

调用并执行方法 (OnItemClick)，但我的 ListItem 的背景颜色保持不变:/

The method (OnItemClick) is called and executed, but the background of my ListItem stays the same color :/

我不敢相信这个简单的任务竟然如此复杂.

I can't believe that this simple task has proven so complicated.

如果我遗漏了可能有用的代码，或者我的问题缺少细节，请随时指出，我会尽力解释自己.

If I have omitted code that could be useful or if my question is lacking details, feel free to point that out and I'll do my best to explain myself.

推荐答案

为所选项目放置一个位置变量.更改 onItemClicked() 方法中的位置.在getView()内检查List Adapter中的选中位置，并设置选中项的背景.

Put a position variable for selected item. Change the position in onItemClicked() method. Check the selected position in List Adapter inside getView() and set the background for the selected item.

public class TestAdapter extends BaseAdapter
{
    private Context context;
    private ArrayList<TestList> testList;
    private int selectedIndex;
    private int selectedColor = Color.parseColor("#1b1b1b");

    public TestAdapter(Context ctx, ArrayList<TestList> testList)
    {
        this.context = ctx;
        this.testList = testList;
        selectedIndex = -1;
    }

    public void setSelectedIndex(int ind)
    {
        selectedIndex = ind;
        notifyDataSetChanged();
    }

    @Override
    public int getCount()
    {
        return testList.size();
    }

    @Override
    public Object getItem(int position)
    {
        return testList.get(position);
    }

    @Override
    public long getItemId(int position)
    {
        return position;
    }

    private class ViewHolder
    {
        TextView tv;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent)
    {
        View vi = convertView;
        ViewHolder holder;
        if(convertView == null)
        {
            vi = LayoutInflater.from(context).inflate(R.layout.test_list_item, null);
            holder = new ViewHolder();

            holder.tv = (TextView) vi;

            vi.setTag(holder);
        }
        else
        {
            holder = (ViewHolder) vi.getTag();
        }

        if(selectedIndex!= -1 && position == selectedIndex)
        {
            holder.tv.setBackgroundColor(Color.BLACK);
        }
        else
        {
            holder.tv.setBackgroundColor(selectedColor);
        }
        holder.tv.setText("" + (position + 1) + " " + testList.get(position).getTestText());

        return vi;
    }

}

现在在单击列表项时设置 selectedIndex 变量.

Now set the selectedIndex variable when a list item clicked.

public class TestActivity extends Activity implements OnItemClickListener
{
    // Implemented onItemClickListener

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id)
    {
        adapter.setSelectedIndex(position);
    }
}

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