ListView: setItemChecked仅适用于标准的ArrayAdapter语言 - 当使用自定义的ArrayAda

Question

这真的很奇怪。

当我使用标准的ArrayAdapter为ListView调用setItemChecked工作OK

但是当使用自定义的ArrayAdapter时，它不会。

原因是什么?这是臭虫吗?还是我错过了什么?

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

您的行布局需要Checkable为setItemChecked()工作，在这种情况下，Android将管理调用setChecked()在您的Checkable作为用户点击行。您不需要设置自己的OnCheckedChangeListener。

更多信息，参见:

• ListView与CHOICE_MODE_MULTIPLE使用CheckedText自定义视图
• 自定义视图的多项选择列表?
• 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

当然你必须为你的ListView设置选择模式，例如:

list.setChoiceMode(ListView.CHOICE_MODE_SINGLE);

但如果你也使用自定义布局的列表项(R.layout.drawing_list_item)，那么你必须确保你的布局实现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));
        }
    }
}

那么你的checkable布局将被定义为如下示例:

<?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

Checkable是我现在不喜欢的学习曲线。您可以在活动的OnItemClickListener中手动设置和取消复选框。在ArrayAdapter<MyObject>的MyObject列表中维护一个布尔isChecked瞬态变量。

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);
}  

说明用户点击CheckBox本身;在CheckBox的OnClickListener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。

public View getView(int position, View convertView, ViewGroup viewGroup) {
        CheckBox cb = null;
        if (convertView == null) {
            if(inflater == null) //cache to avoid reconstructing for each view
            inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView =inflater.inflate(R.layout.list_item_text_right_checkmark, null);
            CheckBox cb = (CheckBox) convertView.findViewById(R.id.check);
            cb.setChecked((list.get(position).isChecked));
            cb.setTag(list.get(position);
            public void onClick(View v) {
                if(v instanceof CheckBox) {
                    CheckBox cb = (CheckBox) v;
                    if(cb.isChecked()) //verify boolean logic here!!!
                        activityRef.get().addItem(cb.getTag()); //WeakReference to activity
                    else
                        activityRef.get().removeItem(cb.getTag());
                }
            });
    } else cb = (CheckBox) convertView.findViewById(R.id.check);
    cb.setChecked((list.get(position).isChecked));
...
}

调用CheckBox::setChecked()是这里的关键。
只要您的数组适配器可以假设相同的活动，并且您的数组适配器可以在res/layout/中假设相同的列表项xml定义，这似乎就可以做到。

checkable list item XML:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
  <TextView
      android:id="@+id/text"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_toLeftOf="@+id/check"
      android:gravity="center_vertical"
      android:paddingLeft="8dp"
      android:textAppearance="?android:attr/textAppearanceMedium" />
  <CheckBox
    android:id="@+id/check"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:focusable="false"/>
</RelativeLayout>

如果你最初需要检查一些checkbox，只需在膨胀之前在MyObject中设置你的isChecked成员。

Answer 4

这些回答对我都不起作用。我的问题是，只有初始调用ExpandableListView。从OnCreate/OnStart/OnPause的settitemchecked没有工作，如果视图还没有完全初始化。为了解决这个问题，我必须做以下操作:

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