I currently have a Qt Application that writes to a log during use and saves the file locally to the device.
This is straightforward enough, I create a QFile with the local path and write to it.
It looks something like this:
QFile logFile;
QString logPath = QStandardPaths::writableLocation(QStandardPaths::DownloadLocation);
logFile.setFileName(logPath.append("/MyLogFile.txt"));
logFile.open(QFile::WriteOnly | QFile::Append);
// Write to log file ...
This works fine but I'd like to also write this log file to a network drive -
E.g. //192.168.12.34/Drive-1/LogFile.txt
I've tried altering the path to //192.168.12.34/Drive-1
but see nothing new in the network folder when I navigate to the above on a desktop.
Is this something that's possible to do from an Android device?
It can't be done this way. You need to mount the network drive first using a samba client, and then copy the files.
You can use a samba client app like AndSMB thats allow folder synchronization for that.
Related
I am trying to read a file that is stored locally on a mobile device.
I'm having trouble knowing where to store it. Read/Write it from.
Should the file be right with the config.xml or stored in the www area on device.
Ultimately the web app is being all served from webpages. But I want to store their login information to do auto logins really.
So read the file : logset.txt
I want to read it by and do a cflocation for auto login:
<cfset fc = #fileRead(expandPath("/logset.txt"), "utf-8")#>
Then if no login settings. Present them a form and write the file, then cflocation to login.
<cfset fpath = expandpath('\')>
<CFFILE ACTION="Write"
FILE="#FPath#logset.txt"
nameConflict="overwrite"
OUTPUT="#nf#">
This all works on the web. But I need it to write the local file to the device and read it from the device. Path issue is what I need sorted I guess.
My application will be used offline and I plan daily pull/push synchronizations via USB cable. My users are in a very primitive situation: no wifi, and no cell phone towers. My question is not about synchronization, but rather just getting access to the data so that I can synchronize.
I connect the cable, select USB for file transfer, and I can see Internal Shared Storage. But I cannot find my SqlLite database anywhere. I have tried using these paths for the database:
Environment.GetFolderPath(System.Environment.SpecialFolder.ApplicationData);
Environment.GetFolderPath(Environment.SpecialFolder.Personal);
Android.App.Application.Context.FilesDir.AbsolutePath;
The app works fine with any of those paths, the data is stored and retrieved, but I cannot see the database from my PC.
I have also tried this but it blows up:
Android.OS.Environment.GetExternalStoragePublicDirectory(Android.OS.Environment.DirectoryDownloads).AbsolutePath;
I have tried debugging with Xamarin Live but then I get this error:
"You need to call SQLitePCL.raw.SetProvider();"
I have tried adding console.writeline and Log.Error to add in some diagnostics but I can't find any log files in Internal Shared Storage.
I have WRITE_EXTERNAL_STORAGE and WRITE_EXTERNAL_STORAGE permissions in the manifest; even tho I think that is not necessary.
If I could store files in Internal Shared Storage then I could put the database there and access it to synchronize. And I could create a simple text logging facility to write a text log to the same place.
I have rarely asked for help in 40 years but I've been at this for days. Thanks!
To get files onto Internal Shared Storage accessible via USB took 3 steps:
1: Get runtime permissions
ActivityCompat.RequestPermissions(activity, new String[] { Manifest.Permission.WriteExternalStorage, Manifest.Permission.ReadExternalStorage }, 1);
2) use this path:
string extPath = Android.OS.Environment.ExternalStorageDirectory.AbsolutePath;
extPath = Path.Combine(extPath, "RtTrace.txt");
File.AppendAllText(extPath, "new content" + System.Environment.NewLine);
3) Media scan the resulting file to make it visible:
MediaScannerConnection.ScanFile(Android.App.Application.Context, new String[] { extPath }, null, null);
The path on Environment.SpecialFolder.Personal refers to a private area where only the app (and the OS itself when you clear data from the app, for example) have access. I don't know about ApplicationData.
You can easily copy your app file (the protected one) to a public folder, like Downloads or create a new folder MyAppDirectory at the public storage space, that will allow access from other devices. Then, you can clear local data that you don't need anymore (after the sync process).
To create a new public folder on Android:
var folder = System.IO.Path.Combine(Android.OS.Environment.ExternalStorageDirectory.AbsolutePath, "MyAppDirectory");
System.IO.Directory.CreateDirectory(folder);
You'll get this:
Then, copy the file:
var newFile = Path.Combine(folder, "MySharedFile"); // The database, xml, json, text or any file you want to share
var sourceFullName = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Personal),"MyOriginalFile");
System.IO.File.Copy(sourceFullName, newFile, true /* overwrite */);
I hope it helps.
SQLite db is stored in application private memory and can't be accessed over USB, try exporting contents of your DB to an external file in your internal memory or External memory to be able to access it via a USB chord.
I'm on an Android 5.0 device where a usb mass storage is mounted at "/storage/usbotg" via USB OTG cable.
Unfortunately from my app I only have read access to that folder. Please note that I set the write external storage permission as I'm able to write to device storage.
I post the following code as reference:
string Root = "/storage/usbotg";
string[] Dirs = Directory.GetDirectories(Root);
string NewFolder = Path.Combine(Root, "NewFolder");
Directory.CreateDirectory(NewFolder);
This gives me an exception on the last line (but I'm able to list subdirectories in Dirs)
Exception:
System.UnauthorizedAccessException
Exception Message:
Access to the path "/storage/usbotg/NewFolder" is denied.
If I use:
string Root = "/storage/emulated/0";
everything is working fine and the "NewFolder" is created.
What I'm missing? How can I write to that folder?
I'm using Xamarin.Forms 2.5.0
Thanks for your help
Accessing data outside your application's private storage using the file system is more restricted with each Android version.
The recommended options are :
Use getExternalFilesDirs(), getExternalCacheDirs, ... : this gives you one or more directories specific to you application (usually directories named after the package name). This does not work for removable media, unless they're adopted.
Use the Storage Access Framework : ask the user (using ACTION_OPEN_DOCUMENT_TREE) to choose the storage root. You can then manage the content of the picked directory through the SAF API. You can persist the permission, so you only need to ask the user once. It seems that it is what ES File explore does to get write permission.
A (much) more detailed explanation by Mark Murphy.
I want to implement video-cast of video from internal storage or sd-card.
I see that this sample (https://github.com/googlecast/CastVideos-android ) does cast of internet content only.
How can I do same thing but using video from device ??
There is some tutorial or sample code ?
Edit:
I do more search, local web server is the way ? Something like nanohttpd ?
Yes, you need to set up a local web server in your android app and serve the media from that server.
step 1:
Run simple http server app in your device
https://play.google.com/store/apps/details?id=jp.ubi.common.http.server&hl=en
step 2: open chrome in your laptop and type your android device's http address (from the above app). you will get your device's directory. copy the address of a video file.
step 3. in CastVideos-android project open VideoProvider.java file.
modify the line :
String videoUrl =
step4: run the CastVideos-android project and enjoy casting.
(try clicking on big buck bunny video, to get the video casted faster)
Im working on an app (flex 4.12 sdk, using flashbuilder 4.5, creating an app for ios and android, testing on an android htc one primarily)... and am using the camera to capture a file... Im then saving that image to the application storage directory, and I want to open the image in the default web browser or trigger a native dialog (android users) to choose the web browser of their choice... how it opens isnt really important right now -- Im mainly trying to just 'access' it with the device and 'load' it outside my air app...
heres the code I have:
var fs2 : FileStream = new FileStream();
fs2.addEventListener(Event.CLOSE, fileCompleteHandler);
var targetFile : File = File.applicationStorageDirectory.resolvePath("test.jpg");
fs2.openAsync(targetFile, FileMode.WRITE);
fs2.writeBytes(myBMDByteArray,0,myBMDByteArray.length);
fs2.close();
and for the event listener that detects the close of the newly created file:
function fileCompleteHandler(e:Event):void {
trace('File saved.');
trace('exists? ' + targetFile.exists);
trace('the url: ' + targetFile.url);
trace('path: ' + targetFile.nativePath);
navigateToURL(new URLRequest(targetFile.url));
}
I get the following info back from this listener
File saved.
exists? true
the url: app-storage:/test.jpg
path: /data/data/air.com.xxxxx.apptesting.debug/com.xxxxx.apptesting.debug/Local Store/test.jpg
... and problem is that navigateToURL cant access the location where the file is stored (the protocol shows in browser as file:///data/data/air.com/xxx... )
how can I use navigateToURL to get access to this newly created file in the web browser or whatever native application the device associates with the file (its a .JPG file)? I also have had success in adding the newly created image to the camera roll but couldnt figure out how to then open that newly saved image in the native camera roll or whatever app the device chooses or presents to the user for the .jpg format.
I can show the user the image INSIDE my app by referencing the bitmap data fine, I just want to give the user access to the physical file that Im creating on their device.
I even have had success in posting (via urlLoader) the bitmap data as base64 encoding and then creating a file on the server side and loading that url but the encoding and trip to and from the server to give the user the image adds a lot of overhead and it takes a little too long and I'd like to avoid that elongated process.
Thanks for any help anyone can provide - let me know if I need to be more specific in any of this.
Solved the issue... I was able to store / write my file in the documentsDirectory using:
var targetFile : File = File.documentsDirectory.resolvePath('test.jpg');
and then
navigateToURL(new URLRequest(targetFile.url));
And this works fine now. Hopefully it helps someone else! Seems that the storage directory SHOULD work but up until now I've only written to and read files stored there... maybe to open the files one HAS to copy it to a 'safe' location in the filesystem (i.e. sd card?)... will move on to test in ios Now - hope all works well in that OS. Thanks all who chimed in on this.
My first hunch is that you need to specify the proper user-permissions in your application descriptor so you can use the openWith functionality with content from your application.
Remember that you need to specify this for IOS and Android specifically.
On your application.xml you need this permissions set inside android > manifestAdditions > manifest:
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
With this permissions you can save files to applicationStorageDirectory:
const FILE_LOADER:URLLoader = new URLLoader();
FILE_LOADER.addEventListener(Event.COMPLETE, onTempFileComplete);
FILE_LOADER.dataFormat = URLLoaderDataFormat.BINARY;
FILE_LOADER.load(new URLRequest(BASE_URL + filePath));
The applicationStorageDirectory can only be accessed by the application it belongs too when using Android or iOS. navigateToURL() hands over your request to the default browser, which cannot access said directory.
documentsDirectory is a public directory in Android, but not in iOS. So it cannot be used for both platforms. Unfortunately none of the pre-compiled file paths File has point to a public directory in iOS. You can find a table explaining all the pre-compiled paths here