我有一个var gamebuttonslist=document.querySelectorAll("#gamebuttons button");
for (var vitem=0;vitem<gamebuttonslist.length;vitem++) {
if (typeof gamebuttonslist[vitem] != "undefined" && gamebuttonslist[vitem] != null) {
gamebuttonslist[vitem].style.cursor = "pointer";
gamebuttonslist[vitem].addEventListener("click", clickHandler, false);
gamebuttonslist[vitem].addEventListener("mousedown", mousedownHandler, false);
gamebuttonslist[vitem].addEventListener("mouseout", mouseoutHandler, false);
}
}
，可以使用此CursorLoader观察目录：
URI
以及使用此uriDirectory = content://com.myapp.stocks/stocks观察项目的另一个CursorLoader：
URI
当我更新uriItem = content://com.myapp.stocks/stocks/GOOG并在uriItem中致电getContext().getContentResolver().notifyChange(uriItem , null);时，如何阻止它同时通知ContentProvider？
谢谢！
修改：所以到目前为止我的解决方案只是在我通知uriDirectory时将boolean设置为true。然后，当它通知父项uriItem时，它将看到布尔值为true并且不会执行任何操作。之后，我将uriDirectory设置回boolean。
答案 0 :(得分：0)
您可以自己编写CursorLoader。默认光标加载器通过Cursor.RegisterContentObserver(ContentObserver observer)注册内容观察者。相反，我们想要使用registerContentObserver(Uri uri, boolean notifyForDescendants, ContentObserver observer)。
我不确定您是否使用支持库loadInBackground()，但为了最大的适用性，这就是我正在使用的。
库存Android版本的唯一变化是loadInBackground。您应该创建一个完整的类，而不是仅仅扩展android＆＃39;并覆盖ContentProvider，因为它可以保护您免受未来对Android的更改。请注意，除非您的设备是KitKat或更新版
Uri notificationUri;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
notificationUri = cursor.getNotificationUri();
} else {
notificationUri = mUri;
}
getContext().getContentResolver().registerContentObserver(
notificationUri != null ? notificationUri : mUri,
false, //don't notify for descendants
mObserver
);
中的光标设置的任何通知网址
package com.innomatixdata.busscan.utils;
import android.content.ContentResolver;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.support.v4.content.AsyncTaskLoader;
import android.support.v4.content.ContentResolverCompat;
import android.support.v4.content.Loader;
import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.util.Arrays;
public class DescendantChangeIgnoringCursorLoader extends AsyncTaskLoader<Cursor> {
final Loader.ForceLoadContentObserver mObserver;
Uri mUri;
String[] mProjection;
String mSelection;
String[] mSelectionArgs;
String mSortOrder;
Cursor mCursor;
android.support.v4.os.CancellationSignal mCancellationSignal;
/* Runs on a worker thread */
@Override
public Cursor loadInBackground() {
synchronized (this) {
if (isLoadInBackgroundCanceled()) {
throw new android.support.v4.os.OperationCanceledException();
}
mCancellationSignal = new android.support.v4.os.CancellationSignal();
}
try {
Cursor cursor = ContentResolverCompat.query(getContext().getContentResolver(),
mUri, mProjection, mSelection, mSelectionArgs, mSortOrder,
mCancellationSignal);
if (cursor != null) {
try {
// Ensure the cursor window is filled.
cursor.getCount();
Uri notificationUri;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
notificationUri = cursor.getNotificationUri();
} else {
notificationUri = mUri;
}
getContext().getContentResolver().registerContentObserver(
notificationUri != null ? notificationUri : mUri,
false, //don't notify for descendants
mObserver
);
} catch (RuntimeException ex) {
cursor.close();
throw ex;
}
}
return cursor;
} finally {
synchronized (this) {
mCancellationSignal = null;
}
}
}
@Override
public void cancelLoadInBackground() {
super.cancelLoadInBackground();
synchronized (this) {
if (mCancellationSignal != null) {
mCancellationSignal.cancel();
}
}
}
/* Runs on the UI thread */
@Override
public void deliverResult(Cursor cursor) {
if (isReset()) {
// An async query came in while the loader is stopped
if (cursor != null) {
cursor.close();
}
return;
}
Cursor oldCursor = mCursor;
mCursor = cursor;
if (isStarted()) {
super.deliverResult(cursor);
}
if (oldCursor != null && oldCursor != cursor && !oldCursor.isClosed()) {
oldCursor.close();
}
}
/**
* Creates an empty unspecified CursorLoader. You must follow this with
* calls to {@link #setUri(Uri)}, {@link #setSelection(String)}, etc
* to specify the query to perform.
*/
public DescendantChangeIgnoringCursorLoader(Context context) {
super(context);
mObserver = new Loader.ForceLoadContentObserver();
}
/**
* Creates a fully-specified CursorLoader. See {@link ContentResolver#query(Uri, String[],
* String, String[], String) ContentResolver.query()} for documentation on the meaning of the
* parameters. These will be passed as-is to that call.
*/
public DescendantChangeIgnoringCursorLoader(Context context, Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
super(context);
mObserver = new Loader.ForceLoadContentObserver();
mUri = uri;
mProjection = projection;
mSelection = selection;
mSelectionArgs = selectionArgs;
mSortOrder = sortOrder;
}
/**
* Starts an asynchronous load of the contacts list data. When the result is ready the callbacks
* will be called on the UI thread. If a previous load has been completed and is still valid
* the result may be passed to the callbacks immediately.
*
* Must be called from the UI thread
*/
@Override
protected void onStartLoading() {
if (mCursor != null) {
deliverResult(mCursor);
}
if (takeContentChanged() || mCursor == null) {
forceLoad();
}
}
/**
* Must be called from the UI thread
*/
@Override
protected void onStopLoading() {
// Attempt to cancel the current load task if possible.
cancelLoad();
}
@Override
public void onCanceled(Cursor cursor) {
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
}
@Override
protected void onReset() {
super.onReset();
// Ensure the loader is stopped
onStopLoading();
if (mCursor != null && !mCursor.isClosed()) {
mCursor.close();
}
mCursor = null;
}
public Uri getUri() {
return mUri;
}
public void setUri(Uri uri) {
mUri = uri;
}
public String[] getProjection() {
return mProjection;
}
public void setProjection(String[] projection) {
mProjection = projection;
}
public String getSelection() {
return mSelection;
}
public void setSelection(String selection) {
mSelection = selection;
}
public String[] getSelectionArgs() {
return mSelectionArgs;
}
public void setSelectionArgs(String[] selectionArgs) {
mSelectionArgs = selectionArgs;
}
public String getSortOrder() {
return mSortOrder;
}
public void setSortOrder(String sortOrder) {
mSortOrder = sortOrder;
}
@Override
public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) {
super.dump(prefix, fd, writer, args);
writer.print(prefix); writer.print("mUri="); writer.println(mUri);
writer.print(prefix); writer.print("mProjection=");
writer.println(Arrays.toString(mProjection));
writer.print(prefix); writer.print("mSelection="); writer.println(mSelection);
writer.print(prefix); writer.print("mSelectionArgs=");
writer.println(Arrays.toString(mSelectionArgs));
writer.print(prefix); writer.print("mSortOrder="); writer.println(mSortOrder);
writer.print(prefix); writer.print("mCursor="); writer.println(mCursor);
}
}
Full class descendantChangeIgnoringCursorLoader.java：
$(window).trigger('resize');