My app creates a number of items when first launched and saves them into /Library/Caches/Thumbnails
The app works great.
When I kill the app, then re-run it, those files are not there any more. This does not happen in the simulator.
I have set the no-not-backup attribute, but still when the app runs after being manually shut down, the cache is empty.
Is there a way to have the cache last a bit longer. This is data not created by the user so can't be put into /Documents.
Adding the following code in my FinishedLaunching method shows a new file at each execution (both on device and on the simulator).
string appdir = NSBundle.MainBundle.BundleUrl.Path;
string cache = Path.GetFullPath (Path.Combine (appdir, "..", "Library", "Caches"));
Console.WriteLine ("Files:");
int i = 0;
foreach (string file in Directory.GetFiles (cache, "*.txt"))
Console.WriteLine ("{0}. {1}", i++, file);
string fname = Path.Combine (cache, i.ToString () + ".txt");
File.WriteAllText (fname, "cache this for later");
So it looks like iOS decided to purge the data to reclaim some space on your device (new feature in iOS 5). This won't happen for every user/devices (if enough space is available) but sadly I do not know how iOS compute this.
Do-not-backup won't help (Caches is never backed up) unless you save your data inside Documents but that could cause you other issues as well (wrt AppStore). For a lack of better answer I suggest you the same as the (previous link) blog author, fill a bug report.
Related
I have a Vue PWA and it stopped creating my IndexDB object stores on first load or upgrade. Here is my code, I am using the latest version of IDB (https://github.com/jakearchibald/idb):
await openDB('dbname', 1, {
upgrade(db, oldVersion, newVersion, transaction) {
switch (newVersion) {
case 0:
// a placeholder case so that the switch block will
// execute when the database is first created
// (oldVersion is 0)
// falls through
case 1:
db.createObjectStore('change_log', {keyPath: 'id'});
db.createObjectStore('person', {keyPath: 'id'})
.createIndex('username', 'username');
break;
}
}
});
I have tried multiple browsers and incognito tabs, etc. and the same thing always happens. The database is created, but no object stores are created. I use developer tools to clear all the data in the PWA and refresh but the same thing happens.
If I increment the version number, the version of my database gets updated in the browser, but the object stores still do not get added.
The upgrade() function does not get called.
I had this happen to me earlier in my development, and I fixed it, but I can't remember how. I feel like it may not actually be a coding issue...
OK, I found the problem. I added a logging mechanism to my App and there was code running BEFORE my upgrade code that was opening the database to create a log entry. Therefore, it was creating the database (with no object stores) before my upgrade method was being called. I changed my open database code to always include the upgrade method to solve my problems.
My problem is this
I'm loading an html string into an UIWebView, in which i'm referencing a local image from my application's Documents folder.
<html><body><img src="image.png"/></body></html>
It loads just fine, no problems with the baseUrl or anything. The problem is when I do some stuff and generate a new image, with the same name, and save it in the same Documents folder, overwriting the old one (I delete the old one if it exists and save the new one).
Now, with the UIWebView still loaded on the screen, if I do a [webview reload] or manually load the html string again, I still get the old image, the one I have just overwritten.
I already checked in the simulator folder, the image.png there is indeed the new image, not the old one. And I already did everything imaginable to stop the webview from caching.
Of course, if I save the new image with a different name, say "image2.png", and reload the html string with src="image2.png", it all shows up ok.
What am I missing here?
Try appending a random query string to your image source.
ie.
function ImageSource(src){
return src + "?time=" + (new Date()).getTime().toString();
}
function ForceImageReloads(){
var images = document.getElementsByTagName("img");
for (var i=0;i<images.length;i++){
var img = images[i];
var s = img.getAttribute("src");
img.src = ImageSource(s);
}
}
ForceImageReloads();
Or something similar to that :)
This maybe a problem with the simulator. I had something similar once. Try running your code on a real device. For me, the simulator seem like it is lazy to reload data that have the same name.
Up until now, this block of code has been using to build documents with text for several months with no snags. I am now trying to dynamically add images. I've spent about two days staring at code and researching and am at an end. I suspect the issue is that relationships are not being created (more details below.) Maybe not?
//set stuff up...
WordprocessingDocument doc = WordprocessingDocument.Open(fsPat, true, new OpenSettings(){
AutoSave = true,
MarkupCompatibilityProcessSettings = new MarkupCompatibilityProcessSettings(MarkupCompatibilityProcessMode.ProcessAllParts,
DocumentFormat.OpenXml.FileFormatVersions.Office2007),
MaxCharactersInPart = long.MaxValue
});
MainDocumentPart mainPart = doc.MainDocumentPart;
.
.Other stuff goes here
.
//now the fun...
Run r2 = new Run();
// Add an ImagePart.
ImagePart ip = mainPart.AddImagePart(ImagePartType.Png);
string imageRelationshipID = mainPart.CreateRelationshipToPart(ip); //
using (Stream imgStream = ip.GetStream())
{
System.Drawing.Bitmap b = new System.Drawing.Bitmap("myfile.png");
b.Save(imgStream, System.Drawing.Imaging.ImageFormat.Png);
}
Drawing drawing = BuildImage(imageRelationshipID, "name"+imageRelationshipID.ToString(), 17, 17);
r2.Append(drawing);
p.Append(r2);
The image part is essentially copied from http://blog.stuartwhiteford.com/?p=33) and is running in a loop presently. I also copied his BuildImage() function and use it as-is.
When I open the resulting docx, I see red Xs where the images are saying "This image cannot currently be displayed."
When I open the zip, the images will appear in root/media, but not root/word/media as I'd expect. I also cannot find the images referenced in any of the relationship files. Ideally they'd be in root/word/_rels/document.xml.rels. You'll notice I changed how imageRelationshipID is set hoping to fix this. It didn't.
Please help. Thank you.
So... It seems like OpenXML just hates me. I copied AddImagePart code from like 3-4 places among trying other things--none of which lasted long--and just could not get relationships to form. The implication I see is that they happen automatically with the AddImagePart function.
I ended up doing a complete workaround where I add all the pictures I might want to put and remove the Drawing nodes' parents of the ones I didn't want (Run nodes, generally.) Since these are very small pictures, it's feasible and in ways more elegant than trying to add them as necessary since I don't have to keep track of where images are stored on disk.
I have developed a C# application, in the application the users choose a photo for each record. However the user should also be able to change the pre-selected photo with a newer one. When the user changes the photo the application first deletes the old photo from the application directory then copies the new photo, but when it does that the application gives an exception because the file is used by the application so it cannot be deleted while the application is running. Does any one have a clue how to sort this out? I appreciate your help
This is the exception
The process cannot access the file
'D:\My
Projects\Hawkar'sProject\Software\Application\bin\Debug\Photos\John
Smith.png' because it is being used by
another process.
//defining a string where contains the file source path
string fileSource = Open.FileName;
//defining a string where it contains the file name
string fileName = personNameTextBox.Text + ".png" ;
//defining a string which specifies the directory of the destination file
string fileDest = dir + #"\Photos\" + fileName;
if (File.Exists(fileDest))
{
File.Delete(fileDest);
//this is a picturebox for showing the images
pbxPersonal.Image = Image.FromFile(dir + #"\Photos\" + "No Image.gif");
File.Copy(fileSource, fileDest);
}
else
{
File.Copy(fileSource, fileDest);
}
imageIDTextBox.Text = fileDest;
First of all, you code is not good.
The new image is only copied if there is currently no image (else).
But if there is an old image, you only delete this image, but never copy the newer one (if).
The code should better look like this:
if (File.Exists(fileDest))
{
File.Delete(fileDest);
}
File.Copy(fileSource, fileDest);
imageIDTextBox.Text = fileDest;
This code should work, but if you are getting an exception that the file is already in use, you should check "where" you use the file. Perhaps you are reading the file at program start. Check all parts of your program you are accessing these user files if there are some handles open.
Thanks a lot for your help and sorry for the mistake in the code I just saw it, my original code is just like as you have written but I don't know maybe when I posted accidentally I've put like this. when the application runs there is a picturebox which the image of each record is shown, that is why the application is giving an exception when I want to change the picture because it has been used once by the picturebox , however I've also tried to load another picture to the picture box before deleting the original one but still the same. I've modified the above could if you want to examine it
I am trying to register to a "Device added/ Device removed" event using WMI. When I say device - I mean something in the lines of a Disk-On-Key or any other device that has files on it which I can access...
I am registering to the event, and the event is raised, but the EventType propery is different from the one I am expecting to see.
The documentation (MSDN) states : 1- config change, 2- Device added, 3-Device removed 4- Docking. For some reason I always get a value of 1.
Any ideas ?
Here's sample code :
public class WMIReceiveEvent
{
public WMIReceiveEvent()
{
try
{
WqlEventQuery query = new WqlEventQuery(
"SELECT * FROM Win32_DeviceChangeEvent");
ManagementEventWatcher watcher = new ManagementEventWatcher(query);
Console.WriteLine("Waiting for an event...");
watcher.EventArrived +=
new EventArrivedEventHandler(
HandleEvent);
// Start listening for events
watcher.Start();
// Do something while waiting for events
System.Threading.Thread.Sleep(10000);
// Stop listening for events
watcher.Stop();
return;
}
catch(ManagementException err)
{
MessageBox.Show("An error occurred while trying to receive an event: " + err.Message);
}
}
private void HandleEvent(object sender,
EventArrivedEventArgs e)
{
Console.WriteLine(e.NewEvent.GetPropertyValue["EventType"]);
}
public static void Main()
{
WMIReceiveEvent receiveEvent = new WMIReceiveEvent();
return;
}
}
Well, I couldn't find the code. Tried on my old RAC account, nothing. Nothing in my old backups. Go figure. But I tried to work out how I did it, and I think this is the correct sequence (I based a lot of it on this article):
Get all drive letters and cache
them.
Wait for the WM_DEVICECHANGE
message, and start a timer with a
timeout of 1 second (this is done to
avoid a lot of spurious
WM_DEVICECHANGE messages that start
as start as soon as you insert the
USB key/other device and only end
when the drive is "settled").
Compare the drive letters with the
old cache and detect the new ones.
Get device information for those.
I know there are other methods, but that proved to be the only one that would work consistently in different versions of windows, and we needed that as my client used the ActiveX control on a webpage that uploaded images from any kind of device you inserted (I think they produced some kind of printing kiosk).
Oh! Yup, I've been through that, but using the raw Windows API calls some time ago, while developing an ActiveX control that detected the insertion of any kind of media. I'll try to unearth the code from my backups and see if I can tell you how I solved it. I'll subscribe to the RSS just in case somebody gets there first.
Well,
u can try win32_logical disk class and bind it to the __Instancecreationevent.
You can easily get the required info
I tried this on my system and I eventually get the right code. It just takes a while. I get a dozen or so events, and one of them is the device connect code.