此页面向您展示如何在 UI 中添加 QuickContactBadge 以及如何将数据绑定到它。 QuickContactBadge 是一个最初显示为缩略图的窗口小部件。虽然您可以为缩略图使用任何 Bitmap，但您通常使用从联系人照片缩略图解码的 Bitmap。
小图片充当控件；当用户点击图片时，QuickContactBadge 会扩展成一个对话框，其中包含以下内容
- 大图片
- 与联系人关联的大图片，或者如果没有图片，则显示一个占位符图形。
- 应用程序图标
- 每个可以由内置应用程序处理的详细信息数据的应用程序图标。例如，如果联系人的详细信息包含一个或多个电子邮件地址，则会显示一个电子邮件图标。当用户点击图标时，会显示联系人的所有电子邮件地址。当用户点击其中一个地址时，电子邮件应用程序会显示一个用于撰写消息的屏幕，该消息将发送到选定的电子邮件地址。
QuickContactBadge 视图提供了对联系人详细信息的即时访问，以及一种与联系人进行快速通信的方式。用户无需查找联系人，找到并复制信息，然后将其粘贴到相应的应用程序中。相反，他们可以点击 QuickContactBadge，选择他们要使用的通信方式，并将该方式的信息直接发送到相应的应用程序。
添加 QuickContactBadge 视图
要添加 QuickContactBadge，请在您的布局中插入 <QuickContactBadge> 元素，如下面的示例所示
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
...
<QuickContactBadge
android:id=@+id/quickbadge
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:scaleType="centerCrop"/>
...
</RelativeLayout>
检索提供程序数据
要在 QuickContactBadge 中显示联系人，您需要联系人的内容 URI 和一个小图片的 Bitmap。您可以从从联系人提供程序检索的列生成内容 URI 和 Bitmap。将这些列指定为用于将数据加载到 Cursor 中的投影的一部分。
对于 Android 3.0（API 级别 11）及更高版本，请在您的投影中包含以下列
对于 Android 2.3.3（API 级别 10）及更低版本，请使用以下列
此页面上的示例假设已加载包含这些列以及任何其他选定列的 Cursor。要了解如何在 Cursor 中检索列，请参阅 检索联系人列表。
设置联系人 URI 和缩略图
获得必要的列后，就可以将数据绑定到 QuickContactBadge。
设置联系人 URI
要设置联系人的内容 URI，请调用 getLookupUri(id,lookupKey) 获取 CONTENT_LOOKUP_URI，然后调用 assignContactUri() 设置联系人。这在下面的示例中显示
Kotlin
// The Cursor that contains contact rows
var cursor: Cursor? = null
// The index of the _ID column in the Cursor
var idColumn: Int = 0
// The index of the LOOKUP_KEY column in the Cursor
var lookupKeyColumn: Int = 0
// A content URI for the desired contact
var contactUri: Uri? = null
// A handle to the QuickContactBadge view
...
cursor?.let { cursor ->
/*
* Insert code here to move to the desired cursor row
*/
// Gets the _ID column index
idColumn = cursor.getColumnIndex(ContactsContract.Contacts._ID)
// Gets the LOOKUP_KEY index
lookupKeyColumn = cursor.getColumnIndex(ContactsContract.Contacts.LOOKUP_KEY)
// Gets a content URI for the contact
contactUri = ContactsContract.Contacts.getLookupUri(
cursor.getLong(idColumn),
cursor.getString(lookupKeyColumn)
)
binding.badge.assignContactUri(contactUri)
}
Java
// The Cursor that contains contact rows
Cursor cursor;
// The index of the _ID column in the Cursor
int idColumn;
// The index of the LOOKUP_KEY column in the Cursor
int lookupKeyColumn;
// A content URI for the desired contact
Uri contactUri;
...
/*
* Insert code here to move to the desired cursor row
*/
// Gets the _ID column index
idColumn = cursor.getColumnIndex(ContactsContract.Contacts._ID);
// Gets the LOOKUP_KEY index
lookupKeyColumn = cursor.getColumnIndex(ContactsContract.Contacts.LOOKUP_KEY);
// Gets a content URI for the contact
contactUri =
Contacts.getLookupUri(
cursor.getLong(idColumn),
cursor.getString(lookupKeyColumn)
);
binding.badge.assignContactUri(contactUri);
当用户点击 QuickContactBadge 图标时，联系人的详细信息会显示在对话框中。
设置照片缩略图
设置 QuickContactBadge 的联系人 URI 不会自动加载联系人的缩略图。要加载照片，请从联系人的 Cursor 行获取照片的 URI，使用它打开包含压缩缩略图的照片文件，并将文件读入 Bitmap。
注意：PHOTO_THUMBNAIL_URI 列在 3.0 之前的平台版本中不可用。对于这些版本，您必须从 Contacts.Photo 子表中检索 URI。
首先，设置变量以访问包含 Contacts._ID 和 Contacts.LOOKUP_KEY 列的 Cursor。
Kotlin
// The column in which to find the thumbnail ID
var thumbnailColumn: Int = 0
/*
* The thumbnail URI, expressed as a String.
* Contacts Provider stores URIs as String values.
*/
var thumbnailUri: String? = null
...
cursor?.let { cursor ->
/*
* Gets the photo thumbnail column index if
* platform version >= Honeycomb
*/
thumbnailColumn = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
cursor.getColumnIndex(ContactsContract.Contacts.PHOTO_THUMBNAIL_URI)
// Otherwise, sets the thumbnail column to the _ID column
} else {
idColumn
}
/*
* Assuming the current Cursor position is the contact you want,
* gets the thumbnail ID
*/
thumbnailUri = cursor.getString(thumbnailColumn)
}
Java
// The column in which to find the thumbnail ID
int thumbnailColumn;
/*
* The thumbnail URI, expressed as a String.
* Contacts Provider stores URIs as String values.
*/
String thumbnailUri;
...
/*
* Gets the photo thumbnail column index if
* platform version >= Honeycomb
*/
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
thumbnailColumn =
cursor.getColumnIndex(ContactsContract.Contacts.PHOTO_THUMBNAIL_URI);
// Otherwise, sets the thumbnail column to the _ID column
} else {
thumbnailColumn = idColumn;
}
/*
* Assuming the current Cursor position is the contact you want,
* gets the thumbnail ID
*/
thumbnailUri = cursor.getString(thumbnailColumn);
...
定义一个方法，该方法接受与联系人的照片相关的数据和目标视图的尺寸，并以 Bitmap 的形式返回适当大小的缩略图。从构造指向缩略图的 URI 开始。
Kotlin
/**
* Load a contact photo thumbnail and return it as a Bitmap,
* resizing the image to the provided image dimensions as needed.
* @param photoData photo ID Prior to Honeycomb, the contact's _ID value.
* For Honeycomb and later, the value of PHOTO_THUMBNAIL_URI.
* @return A thumbnail Bitmap, sized to the provided width and height.
* Returns null if the thumbnail is not found.
*/
private fun loadContactPhotoThumbnail(photoData: String): Bitmap? {
// Creates an asset file descriptor for the thumbnail file
var afd: AssetFileDescriptor? = null
// try-catch block for file not found
try {
// Creates a holder for the URI
val thumbUri: Uri = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
// If Android 3.0 or later,
// sets the URI from the incoming PHOTO_THUMBNAIL_URI
Uri.parse(photoData)
} else {
// Prior to Android 3.0, constructs a photo Uri using _ID
/*
* Creates a contact URI from the Contacts content URI
* incoming photoData (_ID)
*/
val contactUri: Uri =
Uri.withAppendedPath(ContactsContract.Contacts.CONTENT_URI, photoData)
/*
* Creates a photo URI by appending the content URI of
* Contacts.Photo
*/
Uri.withAppendedPath(contactUri, ContactsContract.Contacts.Photo.CONTENT_DIRECTORY)
}
/*
* Retrieves an AssetFileDescriptor object for the thumbnail URI
* using ContentResolver.openAssetFileDescriptor
*/
afd = activity?.contentResolver?.openAssetFileDescriptor(thumbUri, "r")
/*
* Gets a file descriptor from the asset file descriptor.
* This object can be used across processes.
*/
return afd?.fileDescriptor?.let {fileDescriptor ->
// Decodes the photo file and returns the result as a Bitmap
// if the file descriptor is valid
BitmapFactory.decodeFileDescriptor(fileDescriptor, null, null)
}
} catch (e: FileNotFoundException) {
/*
* Handle file not found errors
*/
null
} finally {
// In all cases, close the asset file descriptor
try {
afd?.close()
} catch (e: IOException) {
}
}
}
Java
/**
* Load a contact photo thumbnail and return it as a Bitmap,
* resizing the image to the provided image dimensions as needed.
* @param photoData photo ID Prior to Honeycomb, the contact's _ID value.
* For Honeycomb and later, the value of PHOTO_THUMBNAIL_URI.
* @return A thumbnail Bitmap, sized to the provided width and height.
* Returns null if the thumbnail is not found.
*/
private Bitmap loadContactPhotoThumbnail(String photoData) {
// Creates an asset file descriptor for the thumbnail file
AssetFileDescriptor afd = null;
// try-catch block for file not found
try {
// Creates a holder for the URI
Uri thumbUri;
// If Android 3.0 or later
if (Build.VERSION.SDK_INT
>=
Build.VERSION_CODES.HONEYCOMB) {
// Sets the URI from the incoming PHOTO_THUMBNAIL_URI
thumbUri = Uri.parse(photoData);
} else {
// Prior to Android 3.0, constructs a photo Uri using _ID
/*
* Creates a contact URI from the Contacts content URI
* incoming photoData (_ID)
*/
final Uri contactUri = Uri.withAppendedPath(
ContactsContract.Contacts.CONTENT_URI, photoData);
/*
* Creates a photo URI by appending the content URI of
* Contacts.Photo
*/
thumbUri =
Uri.withAppendedPath(
contactUri, ContactsContract.Contacts.Photo.CONTENT_DIRECTORY);
}
/*
* Retrieves an AssetFileDescriptor object for the thumbnail URI
* using ContentResolver.openAssetFileDescriptor
*/
afd = getActivity().getContentResolver().
openAssetFileDescriptor(thumbUri, "r");
/*
* Gets a file descriptor from the asset file descriptor.
* This object can be used across processes.
*/
FileDescriptor fileDescriptor = afd.getFileDescriptor();
// Decodes the photo file and returns the result as a Bitmap
// if the file descriptor is valid
if (fileDescriptor != null) {
// Decodes the bitmap
return BitmapFactory.decodeFileDescriptor(
fileDescriptor, null, null);
}
// If the file isn't found
} catch (FileNotFoundException e) {
/*
* Handle file not found errors
*/
// In all cases, close the asset file descriptor
} finally {
if (afd != null) {
try {
afd.close();
} catch (IOException e) {}
}
}
return null;
}
在您的代码中调用 loadContactPhotoThumbnail() 方法以获取缩略图 Bitmap，并使用结果在您的 QuickContactBadge 中设置照片缩略图。
Kotlin
...
/*
* Decodes the thumbnail file to a Bitmap
*/
mThumbnailUri?.also { thumbnailUri ->
loadContactPhotoThumbnail(thumbnailUri).also { thumbnail ->
/*
* Sets the image in the QuickContactBadge.
* QuickContactBadge inherits from ImageView.
*/
badge.setImageBitmap(thumbnail)
}
}
Java
...
/*
* Decodes the thumbnail file to a Bitmap
*/
Bitmap mThumbnail =
loadContactPhotoThumbnail(thumbnailUri);
/*
* Sets the image in the QuickContactBadge.
* QuickContactBadge inherits from ImageView.
*/
badge.setImageBitmap(mThumbnail);
将 QuickContactBadge 添加到 ListView
QuickContactBadge 是 ListView 的一个有用补充，它显示联系人列表。使用 QuickContactBadge 为每个联系人显示缩略图；当用户点击缩略图时，将显示 QuickContactBadge 对话框。
添加 QuickContactBadge 元素
首先，将 QuickContactBadge 视图元素添加到您的项目布局中。例如，如果您想为检索到的每个联系人显示 QuickContactBadge 和名称，请将以下 XML 放入布局文件中。
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<QuickContactBadge
android:id="@+id/quickcontact"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:scaleType="centerCrop"/>
<TextView android:id="@+id/displayname"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_toRightOf="@+id/quickcontact"
android:gravity="center_vertical"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"/>
</RelativeLayout>
在以下部分，此文件称为 contact_item_layout.xml。
设置自定义 CursorAdapter
要将 CursorAdapter 绑定到包含 QuickContactBadge 的 ListView，请定义一个扩展 CursorAdapter 的自定义适配器。这种方法允许您在将数据绑定到 QuickContactBadge 之前处理 Cursor 中的数据。这种方法还允许您将多个 Cursor 列绑定到 QuickContactBadge。在常规 CursorAdapter 中，这两种操作都不可能。
您定义的 CursorAdapter 的子类必须重写以下方法
CursorAdapter.newView()- 为保存项目布局膨胀一个新的
View对象。在对该方法的重写中，存储对布局的子View对象的句柄，包括子QuickContactBadge。通过采用这种方法，您可以避免每次膨胀新布局时都必须获取对子View对象的句柄。您必须重写此方法，以便您可以获取对各个子
View对象的句柄。这种技术可以让您在CursorAdapter.bindView()中控制它们的绑定。 CursorAdapter.bindView()- 将数据从当前
Cursor行移动到项目布局的子View对象。您必须重写此方法，以便您可以将联系人的 URI 和缩略图都绑定到QuickContactBadge。默认实现仅允许在列和View之间进行一对一的映射。
以下代码片段包含自定义 CursorAdapter 子类的示例
定义自定义列表适配器
定义 CursorAdapter 的子类，包括其构造函数，并重写 newView() 和 bindView()
Kotlin
/**
* Defines a class that holds resource IDs of each item layout
* row to prevent having to look them up each time data is
* bound to a row
*/
private data class ViewHolder(
internal var displayname: TextView? = null,
internal var quickcontact: QuickContactBadge? = null
)
/**
*
*
*/
private inner class ContactsAdapter(
context: Context,
val inflater: LayoutInflater = LayoutInflater.from(context)
) : CursorAdapter(context, null, 0) {
...
override fun newView(
context: Context,
cursor: Cursor,
viewGroup: ViewGroup
): View {
/* Inflates the item layout. Stores view references
* in a ViewHolder class to prevent having to look
* them up each time bindView() is called.
*/
return ContactListLayoutBinding.inflate(inflater,
viewGroup,
false).also { binding ->
view.tag = ViewHolder().apply {
displayname = binding.displayname
quickcontact = binding.quickcontact
}
}.root
}
...
override fun bindView(view: View?, context: Context?, cursor: Cursor?) {
(view?.tag as? ViewHolder)?.also { holder ->
cursor?.apply {
...
// Sets the display name in the layout
holder.displayname?.text = getString(displayNameIndex)
...
/*
* Generates a contact URI for the QuickContactBadge
*/
ContactsContract.Contacts.getLookupUri(
getLong(idIndex),
cursor.getString(lookupKeyIndex)
).also { contactUri ->
holder.quickcontact?.assignContactUri(contactUri)
}
getString(photoDataIndex)?.also {photoData ->
/*
* Decodes the thumbnail file to a Bitmap.
* The method loadContactPhotoThumbnail() is defined
* in the section "Set the contact URI and thumbnail."
*/
loadContactPhotoThumbnail(photoData)?.also { thumbnailBitmap ->
/*
* Sets the image in the QuickContactBadge.
* QuickContactBadge inherits from ImageView.
*/
holder.quickcontact?.setImageBitmap(thumbnailBitmap)
}
}
}
}
}
}
Java
private class ContactsAdapter extends CursorAdapter {
private LayoutInflater inflater;
...
public ContactsAdapter(Context context) {
super(context, null, 0);
/*
* Gets an inflater that can instantiate
* the ListView layout from the file
*/
inflater = LayoutInflater.from(context);
...
}
...
/**
* Defines a class that holds resource IDs of each item layout
* row to prevent having to look them up each time data is
* bound to a row
*/
private class ViewHolder {
TextView displayname;
QuickContactBadge quickcontact;
}
...
@Override
public View newView(
Context context,
Cursor cursor,
ViewGroup viewGroup) {
/* Inflates the item layout. Stores view references
* in a ViewHolder class to prevent having to look
* them up each time bindView() is called.
*/
final ContactListLayoutBinding binding =
ContactListLayoutBinding.inflate(inflater,
viewGroup,
false);
final ViewHolder holder = new ViewHolder();
holder.displayname =
binding.displayName;
holder.quickcontact =
binding.quickContact;
view.setTag(holder);
return binding.root;
}
...
@Override
public void bindView(
View view,
Context context,
Cursor cursor) {
final ViewHolder holder = (ViewHolder) view.getTag();
final String photoData =
cursor.getString(photoDataIndex);
final String displayName =
cursor.getString(displayNameIndex);
...
// Sets the display name in the layout
holder.displayname = cursor.getString(displayNameIndex);
...
/*
* Generates a contact URI for the QuickContactBadge
*/
final Uri contactUri = Contacts.getLookupUri(
cursor.getLong(idIndex),
cursor.getString(lookupKeyIndex));
holder.quickcontact.assignContactUri(contactUri);
String photoData = cursor.getString(photoDataIndex);
/*
* Decodes the thumbnail file to a Bitmap.
* The method loadContactPhotoThumbnail() is defined
* in the section "Set the contact URI and thumbnail."
*/
Bitmap thumbnailBitmap =
loadContactPhotoThumbnail(photoData);
/*
* Sets the image in the QuickContactBadge.
* QuickContactBadge inherits from ImageView.
*/
holder.quickcontact.setImageBitmap(thumbnailBitmap);
}
设置变量
在您的代码中，设置变量，包括一个 Cursor 投影，其中包含必要的列，如以下示例所示。
注意：以下代码片段使用 loadContactPhotoThumbnail() 方法，该方法在 设置联系人 URI 和缩略图 部分定义。
Kotlin
/*
* Defines a projection based on platform version. This ensures
* that you retrieve the correct columns.
*/
private val PROJECTION: Array<out String> = arrayOf(
ContactsContract.Contacts._ID,
ContactsContract.Contacts.LOOKUP_KEY,
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
ContactsContract.Contacts.DISPLAY_NAME_PRIMARY
} else {
ContactsContract.Contacts.DISPLAY_NAME
},
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
ContactsContract.Contacts.PHOTO_FILE_ID
} else {
/*
* Although it's not necessary to include the
* column twice, this keeps the number of
* columns the same regardless of version
*/
ContactsContract.Contacts._ID
}
)
...
class ContactsFragment : Fragment(), LoaderManager.LoaderCallbacks<Cursor> {
...
// Defines a ListView
private val listView: ListView? = null
// Defines a ContactsAdapter
private val adapter: ContactsAdapter? = null
...
// Defines a Cursor to contain the retrieved data
private val cursor: Cursor? = null
/*
* As a shortcut, defines constants for the
* column indexes in the Cursor. The index is
* 0-based and always matches the column order
* in the projection.
*/
// Column index of the _ID column
private val idIndex = 0
// Column index of the LOOKUP_KEY column
private val lookupKeyIndex = 1
// Column index of the display name column
private val displayNameIndex = 3
/*
* Column index of the photo data column.
* It's PHOTO_THUMBNAIL_URI for Honeycomb and later,
* and _ID for previous versions.
*/
private val photoDataIndex: Int =
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) 3 else 0
...
Java
public class ContactsFragment extends Fragment implements
LoaderManager.LoaderCallbacks<Cursor> {
...
// Defines a ListView
private ListView listView;
// Defines a ContactsAdapter
private ContactsAdapter adapter;
...
// Defines a Cursor to contain the retrieved data
private Cursor cursor;
/*
* Defines a projection based on platform version. This ensures
* that you retrieve the correct columns.
*/
private static final String[] PROJECTION =
{
ContactsContract.Contacts._ID,
ContactsContract.Contacts.LOOKUP_KEY,
(Build.VERSION.SDK_INT >=
Build.VERSION_CODES.HONEYCOMB) ?
ContactsContract.Contacts.DISPLAY_NAME_PRIMARY :
ContactsContract.Contacts.DISPLAY_NAME
(Build.VERSION.SDK_INT >=
Build.VERSION_CODES.HONEYCOMB) ?
ContactsContract.Contacts.PHOTO_FILE_ID :
/*
* Although it's not necessary to include the
* column twice, this keeps the number of
* columns the same regardless of version
*/
ContactsContract.Contacts._ID
};
/*
* As a shortcut, defines constants for the
* column indexes in the Cursor. The index is
* 0-based and always matches the column order
* in the projection.
*/
// Column index of the _ID column
private int idIndex = 0;
// Column index of the LOOKUP_KEY column
private int lookupKeyIndex = 1;
// Column index of the display name column
private int displayNameIndex = 3;
/*
* Column index of the photo data column.
* It's PHOTO_THUMBNAIL_URI for Honeycomb and later,
* and _ID for previous versions.
*/
private int photoDataIndex =
Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB ?
3 :
0;
...
设置 ListView
在 Fragment.onCreate() 中，实例化自定义游标适配器并获取对 ListView 的句柄。
Kotlin
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return FragmentListViewBinding.inflate(...).let { binding ->
...
/*
* Gets a handle to the ListView in the file
* contact_list_layout.xml
*/
listView = binding.contactList
mAdapter?.also {
listView?.adapter = it
}
...
}.root
}
...
Java
@Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
FragmentListViewBinding binding = FragmentListViewBinding.inflate(...)
...
/*
* Gets a handle to the ListView in the file
* contact_list_layout.xml
*/
if (binding.contactListView != null && adapter != null) {
binding.contactListView.setAdapter(adapter);
}
...
}
...
在 onViewCreated() 中，将 ContactsAdapter 绑定到 ListView。
Kotlin
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
/*
* Instantiates the subclass of
* CursorAdapter
*/
mAdapter = activity?.let {
ContactsAdapter(it).also { adapter ->
// Sets up the adapter for the ListView
listView?.adapter = adapter
}
}
}
Java
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
...
/*
* Instantiates the subclass of
* CursorAdapter
*/
mAdapter = new ContactsAdapter(getActivity());
// Sets up the adapter for the ListView
if (listView != null && mAdapter != null) {
listView.setAdapter(mAdapter);
}
...
}
...
当您获得包含联系人数据的 Cursor 时，通常在 onLoadFinished() 中，调用 swapCursor() 将 Cursor 数据移动到 ListView。这将为联系人列表中的每个条目显示 QuickContactBadge。
Kotlin
override fun onLoadFinished(loader: Loader<Cursor>, cursor: Cursor) {
// When the loader has completed, swap the cursor into the adapter
mAdapter?.swapCursor(cursor)
}
Java
public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
// When the loader has completed, swap the cursor into the adapter
mAdapter.swapCursor(cursor);
}
当您使用 CursorAdapter（或子类）将 Cursor 绑定到带有 QuickContactBadge 的 ListView 时，并且您使用 CursorLoader 加载 Cursor 时，始终在您对 onLoaderReset() 的实现中清除对 Cursor 的引用。这在以下示例中显示
Kotlin
override fun onLoaderReset(loader: Loader<Cursor>) {
// Removes remaining reference to the previous Cursor
adapter?.swapCursor(null)
}
Java
@Override
public void onLoaderReset(Loader<Cursor> loader) {
// Removes remaining reference to the previous Cursor
adapter.swapCursor(null);
}