Question

我有一个实现ListView的相当简单的程序。当我在列表中选择一个项目时，它会短暂地变为橙色，然后恢复为黑色。但是，我希望在选择项目后保持橙色（直到我清除项目或选择其他项目）。我尝试编码但失败了。我认为它必须接近正确。任何人都可以在下面的代码中告诉我需要修改什么来使它工作吗？

文件：./ res /layout / main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"              android:layout_width="match_parent"
    android:layout_height="match_parent"        android:gravity="center">
    <ListView
        android:id="@android:id/list"           android:layout_width="match_parent"
        android:layout_height="match_parent"    android:background="@drawable/list_selector"/>
</LinearLayout>

文件：./ are / drawable / list_selector.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true"         android:drawable="@color/orange" />
    <item android:state_selected="false"        android:drawable="@android:color/black" />
</selector>

文件：./ res / values / colors.xml

<?xml version="1.0" encoding="utf-8"?>
    <resources>    <color name="orange">#b0e0e6</color> </resources>

文件：./ src / com / commware / android / linearpct / LinearLayoutDemo.java

public class LinearLayoutDemo extends ListActivity implements OnItemClickListener {
    private static final String[] items={"1", "2", "4", "8", "16", "32", "64", "128", "256", "512", "1024", "2048", "4096", "8192"};
    ListView myLV;
    ArrayAdapter myAdapter;

    @Override public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.main);
        Log.d("LinearLayoutDemo:", "********: onCreate() begin");
        getListView().setOnItemClickListener(this);
        myAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, items);
        myLV = (ListView) findViewById(android.R.id.list);
        myLV.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
        myLV.setAdapter(myAdapter);
    }

    @Override public void onItemClick(AdapterView<?> arg0, View view, int position, long lng) {
        view.setSelected(true);
        String selectedFromList =(String) (myLV.getItemAtPosition(position));
        Log.d("LinearLayoutDemo:", "********: OnItemClick: " + selectedFromList);
    }

    @Override public void onListItemClick(ListView parent, View view, int position, long id) {
        super.onListItemClick(parent, view, position, id);
        view.setSelected(true);
        String selectedFromList =(String) (myLV.getItemAtPosition(position));
        Log.d("LinearLayoutDemo:", "********: OnItemClick: " + selectedFromList);
    }
}

注意：当我运行此代码时，来自onListItemClick（）的日志消息永远不会显示在日志中。那里有些不对劲。

另外，我无法弄清楚如何在onItemClick（）中调用super.onItemClick（）。这可能是一个线索。

Answer 1

list_selector.xml中的

：

<item android:state_selected="true" android:drawable="@color/orange" />

当对象使用D-PAD（跟踪板）

聚焦时调用

<item android:state_activated="true" android:drawable="@color/orange" />

在上下文操作栏中选择对象时调用

。（仅限API 11 +）

API 11中的

- 实现多选的最佳方法是自定义适配器，以更改视图bakground颜色。

    class CPGAdapter extends ArrayAdapter<Pack> {
public void UpdateItem() {
    notifyDataSetChanged();
}

@Override
public View getView(int position, View v, ViewGroup parent) {
    View mView = v;
    if (mView == null) {
        LayoutInflater vi = (LayoutInflater) getContext().getSystemService(
                Context.LAYOUT_INFLATER_SERVICE);
        mView = vi.inflate(R.layout.cpga_xml, null);
    } // inflate
    TextView text = (TextView) mView.findViewById(R.id.tv_cpgatitle);
    // get views from ids
    if (mView != null) {
        if (getItem(position).Selected) {
            mView.setBackgroundResource(R.color.pressed);
        } else {
            mView.setBackgroundResource(R.color.default);
        }
        text.setText(getItem(position).Name);

    }
    return mView;
}

    }

并在您选择View时的代码中：

public void onItemClick(AdapterView<?> AV, View v, int POS, long Id) {
                ((Pack) AV.getItemAtPosition(POS)).Selected = true;
                v.setBackgroundResource(R.color.pressed);
                                    // or (CPGAdapter(AV.getAdapter)).UpdateItem()
}

Answer 2

将simple_list_item_1更改为simple_list_item_activated_1。颜色非常难看，如果你想要漂亮的颜色，你必须扩展ArrayAdapter。

public class LinearLayoutDemo extends ListActivity implements OnItemClickListener {
    private static final String[] items={"1", "2", "4", "8", "16", "32", "64", "128", "256", "512", "1024", "2048", "4096", "8192"};
    ListView myLV;
    ArrayAdapter myAdapter;

@Override public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.main);
    Log.d("LinearLayoutDemo:", "********: onCreate() begin");

    myAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_activated_1, items);
    myLV = (ListView) findViewById(android.R.id.list);
    myLV.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
    myLV.setAdapter(myAdapter);
    myLV.setOnItemClickListener(this);
}

@Override public void onItemClick(AdapterView<?> arg0, View view, int position, long lng) {

    String selectedFromList =(String) (myLV.getItemAtPosition(position));
    Log.d("LinearLayoutDemo:", "********: OnItemClick: " + selectedFromList);
}


}

您可以移除list_selector.xml并更改布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"              android:layout_width="match_parent"
android:layout_height="match_parent"        android:gravity="center">
<ListView
    android:id="@android:id/list"           android:layout_width="match_parent"
    android:layout_height="match_parent" />
</LinearLayout>

Answer 3

查看State List，尤其是android:state_activated="true"

ListView：应突出显示所选项目

3 个答案: