android提供了本地数据库的查询uri,能够查询出数据:
採用一个AsyncQueryHandler来进行查询, AsyncQueryHandler自己开启了线程来进行数据查询，非常方便
protected AsyncQueryHandler mQueryHandler;
protected final void queryPersonal() {
mQueryHandler.startQuery(QUERY_TOKEN, null, ContactsContract.Contacts.CONTENT_URI,
Personal.CONTACTS_SUMMARY_PROJECTION, null, null, getSortOrder(ContactsContract.Contacts.DISPLAY_NAME));
}
protected static String getSortOrder(String fieldName) {
//substr为截取函数。取第一个字母
//COLLATE主要用于对字符进行排
//COLLATE LOCALIZED 按本地语言进行排序
return "CASE WHEN substr(UPPER(" + fieldName + "), 1, 1) BETWEEN 'A' AND 'Z' THEN 1 else 10 END," +
fieldName + " COLLATE LOCALIZED ASC";
}
protected final class MyHandler extends AsyncQueryHandler {
/**
* Asynchronous query handler constructor.
*/
public MyHandler(Context context) {
super(context.getContentResolver());
}
/**
* On query completion.
*/
@Override
<strong>protected void onQueryComplete(int token, Object cookie, Cursor cursor) </strong>{ //handler查询完的回调
if (cursor == null || cursor.isClosed()) {
return;
}
if (!isFinishing()) {
setLoading(false);
if (mAdapter != null) {
mAdapter.setLoading(false);
mAdapter.changeCursor(cursor);
}
if (cursor.getCount() == 0) {
mEmtytext.setVisibility(View.VISIBLE);
} else {
mEmtytext.setVisibility(View.INVISIBLE);
}
} else {
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
}
}
}这个Layout是:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:rcm="http://schemas.android.com/apk/res/com.ringcentral.android" android:id="@+id/contact_list_view" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@color/bgColorMain" android:orientation="vertical"> <ListView android:id="@android:id/list" android:layout_width="match_parent" android:layout_height="match_parent" android:cacheColorHint="@android:color/transparent" android:descendantFocusability="afterDescendants" android:divider="@null" android:fastScrollEnabled="true" android:listSelector="@drawable/bg_list_item_selector" /> <RelativeLayout android:id="@+id/no_contact_indication" android:layout_width="match_parent" android:layout_height="match_parent"> <TextView android:id="@+id/emptyListText" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:singleLine="true" android:text="No Contacts" android:textColor="@color/text_no_items" android:textSize="20sp" /> <ProgressBar android:id="@+id/loading" style="@style/RCMProgressBar" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:visibility="gone" /> </RelativeLayout> </LinearLayout>
然后是list adapter的写法:
protected static final class SectionedContactListItemCache {
public TextView sectionHeader;
public TextView nameView;
public TextView typeView;
public ImageView photoView;
public ImageView detailItemIcon;
<span style="white-space:pre"> </span>public View nameTypeWrapper;
}
protected final class ContactsAdapter extends ResourceCursorAdapter {
public ContactsAdapter(Context context) {
super(context, R.layout.contacts_list_item_photo,null);
}
@Override
public void changeCursor(Cursor c) {
super.changeCursor(c);
}
protected String getTitle(String displayName) {
String title;
/** check if the first letter is English letter */
Matcher matcher = mPattern.matcher(displayName);
if (!matcher.find()) {
title = NONE_ENGLISH_LETTER_TITLE;
} else {
title = displayName.trim().substring(0, 1).toUpperCase(Locale.US);
}
return title;
}
protected String getDisplayName(Cursor c) {
String displayName = c.getString(Personal.NAME_COLUMN_INDEX);
if(TextUtils.isEmpty(displayName)) {
return "";
}
return displayName;
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
final SectionedContactListItemCache cache = (SectionedContactListItemCache) view.getTag();
cache.typeView.setVisibility(View.GONE);
cache.photoView.setVisibility(View.VISIBLE);
String name = cursor.getString(Personal.NAME_COLUMN_INDEX);
if (TextUtils.isEmpty(name)) {
cache.nameView.setText(R.string.contact_no_name);
} else {
cache.nameView.setText(name);
}
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
View view = super.newView(context, cursor, parent);
final SectionedContactListItemCache cache = new SectionedContactListItemCache();
cache.nameTypeWrapper = view.findViewById(R.id.name_type);
cache.sectionHeader = (TextView) view.findViewById(R.id.txtSectionHeader);
cache.nameView = (TextView) view.findViewById(R.id.name);
cache.typeView = (TextView) view.findViewById(R.id.type);
cache.photoView = (ImageView) view.findViewById(R.id.photo);
cache.detailItemIcon = (ImageView) view.findViewById(R.id.contacts_detail_item_icon);
view.setTag(cache);
return view;
}
}//end of adapteritem adapter的layout:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical"> <TextView android:id="@+id/txtSectionHeader" android:layout_width="match_parent" android:layout_height="@dimen/list_item_section_height" android:background="@drawable/bg_contacts_section_header" android:gravity="center_vertical|left" android:paddingLeft="@dimen/default_padding_to_side" android:textColor="@color/contacts_text_separator_text_color" android:textSize="@dimen/font_size_medium" /> <RelativeLayout android:id="@+id/contact_item" android:layout_width="match_parent" android:layout_height="@dimen/general_list_view_item_height"> <ImageView android:id="@+id/photo" android:layout_width="@dimen/favorites_item_picture_width" android:layout_height="match_parent" android:layout_alignParentLeft="true" android:layout_alignWithParentIfMissing="true" android:paddingTop="6dp" android:paddingBottom="6dp" android:layout_marginLeft="@dimen/contact_photo_margin_left_right" android:scaleType="fitCenter" /> <!-- this icon may be added in next version, and now it would be hidden --> <ImageView android:id="@+id/contacts_detail_item_icon" android:layout_width="50dip" android:layout_height="60dip" android:layout_alignParentRight="true" android:layout_marginRight="0dip" android:cropToPadding="true" android:duplicateParentState="false" android:paddingBottom="3dip" android:paddingTop="3dip" android:scaleType="fitCenter" android:src="@drawable/ic_list_link" android:visibility="gone" /> <RelativeLayout android:id="@+id/name_type" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_alignWithParentIfMissing="true" android:layout_toLeftOf="@id/contacts_detail_item_icon" android:layout_marginLeft="@dimen/contact_photo_margin_left_right" android:layout_toRightOf="@id/photo" android:background="@drawable/bg_list_item_divider"> <TextView android:id="@+id/type" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignBaseline="@+id/name" android:layout_alignParentRight="true" android:layout_marginRight="@dimen/contact_type_margin_left_right" android:ellipsize="marquee" android:gravity="center_vertical|right" android:singleLine="true" android:textColor="@color/refresh_control_text_color" android:textSize="@dimen/font_size_small" /> <TextView android:id="@+id/name" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_centerVertical="true" android:layout_marginRight="@dimen/contact_name_margin_left_right" android:layout_toLeftOf="@id/type" android:ellipsize="marquee" android:gravity="center_vertical|left" android:singleLine="true" android:textColor="@color/text_color_main" android:textSize="@dimen/font_size_medium" /> </RelativeLayout> </RelativeLayout> </LinearLayout>