ListView：setItemChecked仅适用于标准ArrayAdapter - 在使用自定义ArrayAdapter时不起作用？

Question

这真的很奇怪。

当我使用标准ArrayAdapter进行ListView调用时，setItemChecked正常工作

但是当使用自定义的ArrayAdapter时，它不会。

原因是什么？这是一个错误吗？或者我错过了什么？

public class Test_Activity extends Activity {

    /** Called when the activity is first created. */
    private List<Model> list;
    private ListView lView;

    public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    // Create an array of Strings, that will be put to our ListActivity
    setContentView(R.layout.main);
    lView = (ListView) findViewById(R.id.ListView01);
    lView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);

    list = getModel();

    //with this adapter setItemChecked works OK
    lView.setAdapter(new ArrayAdapter<Model>(this,
        android.R.layout.simple_list_item_multiple_choice, list));


  //**************************
    //PROBLEM: with this adapter it does not check any items on the screen
    // ArrayAdapter<Model> adapter = new Test_Class1(this, list);
    // lView.setAdapter(adapter);



    }

    private List<Model> getModel() {
       List<Model> list = new ArrayList<Model>();
       list.add(get("0"));
       list.add(get("1"));
       list.add(get("2"));
       list.get(1).setSelected(true);
       Model m = list.get(1);
       list.add(get("3"));
       list.add(get("4"));
       list.add(get("5"));
       list.add(get("6"));
       list.add(get("7"));
       // Initially select one of the items
       return list;
    }

    private Model get(String s) {
       return new Model(s);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
       MenuInflater inflater = getMenuInflater();
       inflater.inflate(R.menu.results_screen_option_menu, menu);
       return true;
    }

    /**
     * @category OptionsMenu
     */
    @Override
 public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case R.id.select_all: {

        int size = lView.getAdapter().getCount();

        for (int i = 0; i <= size; i++) {

            //************************** PROBLEM
        lView.setItemChecked(i, true); // selects the item only for standard ArrayAdapter

    Log.i("xxx", "looping " + i);
        }
    }
        return true;
    case R.id.select_none:
        return true;
    }
    return false;
    }
}

// --------------------------------------------- ---------------

public class Test_Class1 extends ArrayAdapter<Model> {

    private final List<Model> list;
    private final Activity context;

 public Test_Class1(Activity context, List<Model> list) {
    super(context, R.layout.rowbuttonlayout2, list);
    this.context = context;
    this.list = list;
    }

  static class ViewHolder {
    protected TextView text;
    protected CheckBox checkbox;
    }

    @Override
 public View getView(int position, View convertView, ViewGroup parent) {
    View view = null;
    Log.i("xxx", "-> getView " + position);
    if (convertView == null) {
        LayoutInflater inflator = context.getLayoutInflater();
        view = inflator.inflate(R.layout.rowbuttonlayout, null);
        final ViewHolder viewHolder = new ViewHolder();
        viewHolder.text = (TextView) view.findViewById(R.id.label);
        viewHolder.checkbox = (CheckBox) view.findViewById(R.id.check);
        viewHolder.checkbox
            .setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(CompoundButton buttonView,
                boolean isChecked) {
                Model element = (Model) viewHolder.checkbox
                    .getTag();
                Log.i("xxx", "-> onCheckedChanged");
                element.setSelected(buttonView.isChecked());
                Log.i("xxx", "<- onCheckedChanged");

            }
            });
        view.setTag(viewHolder);
        viewHolder.checkbox.setTag(list.get(position));
    } else {
        view = convertView;
        ((ViewHolder) view.getTag()).checkbox.setTag(list.get(position));
    }
    ViewHolder holder = (ViewHolder) view.getTag();
    holder.text.setText(list.get(position).getName());
    Log.i("xxx", "holder.checkbox.setChecked: " + position);

    holder.checkbox.setChecked(list.get(position).isSelected());
    Log.i("xxx", "<-  getView " + position);

    return view;
    }

}

Answer 1

Checkable的行布局必须setItemChecked()才能正常工作，在这种情况下，当用户点击该行时，Android会管理setChecked()上的Checkable来电。您无需设置自己的OnCheckedChangeListener。

有关更多信息，请参阅：

• ListView with CHOICE_MODE_MULTIPLE using CheckedText in a custom view
• Multiple choice list with custom view?
• http://www.marvinlabs.com/2010/10/custom-listview-ability-check-items/
• http://tokudu.com/2010/android-checkable-linear-layout/
• http://alvinalexander.com/java/jwarehouse/apps-for-android/RingsExtended/src/com/example/android/rings_extended/CheckableRelativeLayout.java.shtml

Answer 2

当然，您必须为ListView设置选择模式，例如：

list.setChoiceMode(ListView.CHOICE_MODE_SINGLE);

但是如果您还为列表项（R.layout.drawing_list_item）使用自定义布局，那么您必须确保您的布局实现了Checkable接口：

public class CheckableRelativeLayout extends RelativeLayout implements Checkable {
    private boolean isChecked = false;

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

    public boolean isChecked() {
        return isChecked;
    }

    public void setChecked(boolean isChecked) {
        this.isChecked = isChecked;
        changeColor(isChecked);
    }

    public void toggle() {
        this.isChecked = !this.isChecked;
        changeColor(this.isChecked);
    }

    private void changeColor(boolean isChecked){
        if (isChecked) {
            setBackgroundColor(getResources().getColor(android.R.color.holo_blue_light));
        } else {
            setBackgroundColor(getResources().getColor(android.R.color.transparent));
        }
    }
}

然后，您的可检查布局将定义为以下示例：

<?xml version="1.0" encoding="utf-8"?>
<it.moondroid.banking.CheckableRelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/drawer_item_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="10dp" >

    <ImageView
        android:id="@+id/agenzie_item_icon"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        android:background="@android:color/darker_gray"
        android:focusable="false" />

    <TextView
        android:id="@+id/agenzie_item_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_toRightOf="@+id/agenzie_item_icon"
        android:focusable="false"
        android:paddingLeft="10dp"
        android:text="item"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:textColor="#FFFFFF" />

</it.moondroid.banking.CheckableRelativeLayout>

Answer 3

可检查是我不愿意接受的学习曲线。您可以在“活动”OnItemClickListener中手动设置和取消设置CheckBox。在isChecked的{​​{1}}列表中维护一个布尔MyObject瞬态变量。

ArrayAdapter<MyObject>

要考虑用户点击public void onItemClick(AdapterView<?> av, View v, int position, long arg3) { final ListView listView = (ListView) findViewById(android.R.id.list); MyObject item = (MyObject) listView.getItemAtPosition(position); item.isChecked = !item.isChecked; if(item.isChecked) addItem(item); else removeItem(item); } 本身;在CheckBox的{​​{1}}中，在自定义数组适配器的getView实现中使用相同的addItem（item）/ removeItem（item）逻辑。

CheckBox

调用CheckBox :: setChecked（）是这里的关键 只要您的数组适配器可以采用相同的活动，并且您的数组适配器可以在res / layout /中采用相同的列表项xml定义，这似乎就可以解决问题。

可检查列表项XML：

OnClickListener

如果您最初需要检查一些CheckBox，只需在充气前在MyObject中设置isChecked成员即可。

Answer 4

没有一个回复对我有用。我的问题是只有从OnCreate / OnStart / OnPause初始调用ExpandableListView.setItemChecked不起作用，就好像视图还没有完全初始化。为了解决这个问题，我必须做到以下几点：

_expandableListView.Post(() =>
{
    _expandableListView.SetItemChecked(fragmentPosition, true);
});