Question

我尝试实现listview multichoice。我想用checkBox项目在列表视图中显示我的所有联系人。我的问题是，当只检查一个项目时，有很多元素正在被解雇。你能帮忙吗？

public class SelectNewGroupChatMembers extends ListFragment implements
        LoaderCallbacks<Cursor>, OnItemClickListener {
/** Defines a tag for identifying log entries */
private static final String TAG = "SelectNewGroupChatMembers";
/** The main query adapter */
private ContactsAdapter mAdapter;
/** ListView which will display contacts */
ListView mListView;
/** Fragments require an empty constructor. */
public SelectNewGroupChatMembers() {
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // Create the main contacts adapter
    mAdapter = new ContactsAdapter(getActivity());
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_list, container, false);
    mListView = (ListView)view.findViewById(android.R.id.list);
    return view;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    Log.i(TAG, "clicked");
    mListView.setAdapter(mAdapter);
    mListView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
    mListView.setOnItemClickListener(this);     
    // Initialize the loader, and create a loader identified by ContactsQuery.QUERY_ID
    getLoaderManager().initLoader(ContactsQuery.QUERY_ID, null, this);
}

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

@Override
public Loader<Cursor> onCreateLoader(int id, Bundle savedInstanceState) {
    // If this is the loader for finding contacts in the Content Provider
    if (id==ContactsQuery.QUERY_ID) {
        Uri contentUri = ContactsQuery.CONTENT_URI;
        Log.i(TAG, contentUri.toString());
        // Create a new CursorLoader with the following query parameters.
        return new CursorLoader(getActivity(),
                contentUri,
                ContactsQuery.PROJECTION,
                ContactsQuery.SELECTION,
                null,
                ContactsQuery.SORT_ORDER);
    }
    Log.i(TAG, "onCreateLoader - incorrect ID provided ( "+ id +" )");
    return null;
}

@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
    // This swaps the new cursor into the adapter.
    if (loader.getId() == ContactsQuery.QUERY_ID) {
        Log.i(TAG,cursor.toString());
        // The asynchronous load is complete and the data
        // is now available for use. Only now can we associate
        // the queried Cursor with the SimpleCursorAdapter.
        mAdapter.swapCursor(cursor);
    }
}

@Override
public void onLoaderReset(Loader<Cursor> loader) {
    if (loader.getId() == ContactsQuery.QUERY_ID) {
        // When the loader is being reset, clear the cursor from the adapter.
        // This allows the cursor resources to be freed.
        mAdapter.swapCursor(null);
    }
}

private class ContactsAdapter extends CursorAdapter {
    private LayoutInflater mInflater;
    public ContactsAdapter(Context context) {
        super(context, null, 0);
        // Stores the inflater for the later use
        mInflater = LayoutInflater.from(context);
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup viewGroup) {
        // Inflate the list item layout
        final View itemLayout = 
                mInflater.inflate(R.layout.fragment_select_new_group_chat_members, viewGroup, false);
        // Use ViewHolder design pattern to store each view resource.
        // This allows bindView() to retrieve stored references instead of 
        // calling findViewById for each instance of the layout.
        final ViewHolder holder = new ViewHolder();
        holder.contactName = (TextView)itemLayout.findViewById(R.id.userName);
        holder.contactNo = (TextView)itemLayout.findViewById(R.id.userInfo);
        // Store the resourceHolder instance in Layout.
        // This makes resourceHolder available to bindView
        // and other methods that receive a handle to the item view
        itemLayout.setTag(holder);
        return itemLayout;
    }
    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        // Get handles to individual view sources
        final ViewHolder holder = (ViewHolder) view.getTag();
        final String contactName = cursor.getString(ContactsQuery.DISPLAY_NAME);
        final String contactNumber = cursor.getString(ContactsQuery.PHONE_NUMBER);
        holder.contactName.setText(contactName);
        holder.contactNo.setText(contactNumber);
    }
    private class ViewHolder {
        public TextView contactName, contactNo;
    }
}

public interface ContactsQuery {
    // This query ID will be used in Loader
    final static int QUERY_ID = 1;
    // A content URI for the Contacts table
    final static Uri CONTENT_URI = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;
    final static String SELECTION = null;
    final static String SORT_ORDER = ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME;
    final static String [] PROJECTION = {
        ContactsContract.CommonDataKinds.Phone._ID,
        ContactsContract.CommonDataKinds.Phone.LOOKUP_KEY,
        ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME,
        ContactsContract.CommonDataKinds.Phone.NUMBER,
        SORT_ORDER,
    };
    final static int ID = 0;
    final static int LOOKUP_KEY = 1;
    final static int DISPLAY_NAME = 2;
    final static int PHONE_NUMBER = 3;
    final static int SORT_KEY = 4;
}
}

我的布局文件如下：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="6dip" >

<ImageView
    android:id="@+id/userImage"
    android:layout_width="50dp"
    android:layout_height="50dp"
    android:layout_marginRight="6dip"
    android:src="@drawable/ic_action_user" />

<CheckBox
    android:id="@+id/checkBox"
    android:layout_width="50dp"
    android:layout_height="50dp"
    android:layout_alignBottom="@id/userImage"
    android:layout_alignTop="@id/userImage"
    android:layout_alignParentRight="true"
    android:focusable="false"
    android:gravity="center" />

<TextView
    android:id="@+id/userName"
    android:layout_alignTop="@id/userImage"
    android:layout_toRightOf="@id/userImage"
    android:layout_toLeftOf="@id/checkBox"
    android:layout_width="wrap_content"
    android:layout_height="25dp"
    android:gravity="center_vertical"
    android:text="ContactName"
    android:textStyle="bold" />

<TextView
    android:id="@+id/userInfo"
    android:layout_alignBottom="@id/userImage"
    android:layout_toRightOf="@id/userImage"
    android:layout_toLeftOf="@id/checkBox"
    android:layout_width="wrap_content"
    android:layout_height="25dp"
    android:gravity="center_vertical"
    android:text="UserInfo" />

</RelativeLayout>

在最后，我的代码就像上面一样。此代码查询联系人并在列表视图上显示它们，其中包括checkBox。我尝试了一些不同的代码片段但是我的所有尝试都得到了相同的结果。我的问题是，当只检查一个项目时，有很多元素正在被解雇。你能帮忙吗？

Answer 1

我没看到你在这个代码中操作项目点击的复选框。理想情况下onItemClick您应该通过调用view.getTag从视图标记中获取Holder对象。在您的持有人中有一个复选框视图实例，因此您可以在此处启用复选框。在 onItemClick 方法上就是这样的。

Holder holder = (Holder) view.getTag();
holder.checkbox.setChecked(!checkbox.isChecked());

ListView multichoice实现只需单击一个选项即可

1 个答案: