Develop Reference

Open PDF file in external app with write permissions

I'm using Launcher.Default.OpenAsync(OpenFileRequest request) to open a PDF file in an external PDF editor. The file loads correctly, but to edit the document this external app asks you to make a copy and edit over that copy, not the original file. I can edit the original file if I open the PDF using the device (Galaxy Tab S6 Lite) file explorer but it's not possible to do the same if I open the same file from my MAUI app.
I see OpenFileRequest constructor asks for a ReadOnlyFile. Is there a way I could create an "OpenFileRequest" with write permissions, or an alternative way to launch the document editor with the file so I can edit it without having to create a copy?
Example code:
var filename = "example.pdf";
var file = new ReadOnlyFile(filename);
var openFileRequest = new OpenFileRequest("PDF Document", file);
await Launcher.Default.OpenAsync(openFileRequest);

I have tried to edit the pdf file with the Pdf Editor in some other apps. But all of them need to save as another file. So it seems only the file explorer can edit the original file.
In addition, the ReadOnlyFile is inherited from the FileBase. So you can try:
var filename = "example.pdf";
var file = new ReadOnlyFile(filename);
var openFileRequest = new OpenFileRequest("PDF Document", file as FileBase);
await Launcher.Default.OpenAsync(openFileRequest);
Actually, the other app doesn't have the permission to write the file in your app. You can refer to this case which is about editing pdf with external application does not overwrite existing file.
I can't find any native android api about grant the others app the write permission of the existing file. This should be the android permission limit.

Writing a file to a phone's internal storage with Xamarin [duplicate]

I want to save my logs to a folder which I can access with windows explorer. For example I want to create my log in the following path
This PC\Galaxy A5 (2017)\Phone\Android\data\MyApp\files
So I tried to use Environment variables... I get such as
/data/user/...
But here i cannot see the file what I created (using code I can access the path but I want to see in the explorer).
how I can create a path like above with code?
When I tried this code
var finalPath2 = Android.OS.Environment.GetExternalStoragePublicDirectory
(Android.OS.Environment.DataDirectory.AbsolutePath);
I get the path "/storage/emulated/0/data"
and
If i use the code
var logDirectory =Path.Combine(System.Environment.GetFolderPath
(System.Environment.SpecialFolder.ApplicationData),"logs");
I get the following path like:
/data/user/0/MyApp/files/.config/logs
and
var logDirectory =Path.Combine(System.Environment.GetFolderPath
(System.Environment.SpecialFolder.MyDocuments),"logs");
"/data/user/0/IM.OneApp.Presentation.Android/files/logs"
but unfortunately I cannot access this folder by explorer....
This PC\Galaxy A5 (2017)\Phone\Android\data\MyApp\files
So how to find out this path in c# by using environments?
Update:
when I give the following path hardcoded, it creates the file where I want..
logDirectory = "/storage/emulated/0/Android/data/MyApp/files/logs";
is there any environment to create this path? I can combine 2 environments and do some string processing in order to create this path. But maybe there is an easier way?

You are looking for the root of GetExternalFilesDir, just pass a null:
Example:
var externalAppPathNoSec = GetExternalFilesDir(string.Empty).Path;
Note: This is a Context-based instance method, you can access it via the Android application context, an Activity, etc... (see the link below to the Android Context docs)
Shared storage may not always be available, since removable media can be ejected by the user. Media state can be checked using Environment.getExternalStorageState(File).
There is no security enforced with these files. For example, any application holding Manifest.permission.WRITE_EXTERNAL_STORAGE can write to these files.
re: https://developer.android.com/reference/android/content/Context#getExternalFilesDir(java.lang.String)

string docFolder = Path.Combine(System.Environment.GetFolderPath
(System.Environment.SpecialFolder.MyDocuments), "logs");
string libFolder = Path.Combine(docFolder, "/storage/emulated/0/Android/data/MyApp/files/logs");
if (!Directory.Exists(libFolder))
{
Directory.CreateDirectory(libFolder);
}
string destinationDatabasePath = Path.Combine(libFolder, "temp.db3");
db.Backup( destinationDatabasePath, "main");

Where is my file in Android application(Xamarin)?

I wrote a test Android app in Xamarin, where sample data was stored in a file. Somehow I copied test data file to emulator, successfully run the app and forgot about the project for couple of months.
Now I am resuscitating the project and - I can't find the file in Android Device Manager although it is still accessible in the emulator. It drives me nuts, I need to edit it!
Perhaps someone can point me to the right way to locate the file. Thanks!
Following is the code fragment that reads the file. I added debug output in the comments after each relevant line
var fileName = "NursePurse.jobjson1.txt";
var assembly = typeof(pageJobs).GetTypeInfo().Assembly;
//assembly.base.CodeBase = "file:///storage/emulated/0/Android/data/NursePurse.Droid/files/.__override__/NursePurse.dll"
String fname = assembly.FullName;
//fname = NursePurse, Version=1.0.6504.22050, Culture=neutral, PublicKeyToken=null
Stream stream = assembly.GetManifestResourceStream(fileName);
List<String> t = assembly.GetManifestResourceNames().ToList();
// there are two entries
// "NursePurse.AppResources.resources","NursePurse.jobjson1.txt"
// here is my file! But I don't see neither of these files in the android device manager.
Question - where is it?
Following is the screenshot of Android Dev.Manager View and Device definition with SIM card

How to correctly load XML files on mobile devices using unity3d

I have some level definitions in xml format (with .txt extension) inside (without any subfolders) my project's rescources folder
I for more scalability, I have a plain text file naming all these level definition XMLs
I read that file using
TextAsset WorldList = (TextAsset)Resources.Load("WorldList");
And then I load the needed world:
TextAsset TA = (TextAsset)Resources.Load(/*"LevelDefs/" +*/ Worlds[worldToload]);
xps.parseXml(TA.text);
loadLevel(levelToLoad);
(you see that I have moved these rescources out of subfolder to reduce the chance of them not loading)
worldToload here is the index number of that world
program works fine on windows but nothing loads on my android test device.
I seem to have problems debugging on device so I only guess something went wrong in loading phase.
any suggestions?

From Unity Documentation:
Most assets in Unity are combined into the project when it is built.
However, it is sometimes useful to place files into the normal
filesystem on the target machine to make them accessible via a
pathname. An example of this is the deployment of a movie file on iOS
devices; the original movie file must be available from a location in
the filesystem to be played by the PlayMovie function.
Any files placed in a folder called StreamingAssets in a Unity project
will be copied verbatim to a particular folder on the target machine.
You can retrieve the folder using the Application.streamingAssetsPath
property. It’s always best to use Application.streamingAssetsPath to
get the location of the StreamingAssets folder, it will always point
to the correct location on the platform where the application is
running.
So below snippet should work:
// Put your file to "YOUR_UNITY_PROJ/Assets/StreamingAssets"
// example: "YOUR_UNITY_PROJ/Assets/StreamingAssets/Your.xml"
if (Application.platform == RuntimePlatform.Android)
{
// Android
string oriPath = System.IO.Path.Combine(Application.streamingAssetsPath, "Your.xml");
// Android only use WWW to read file
WWW reader = new WWW(oriPath);
while ( ! reader.isDone) {}
realPath = Application.persistentDataPath + "/Your"; // no extension ".xml"
var contents = System.IO.File.ReadAll(realPath);
}
else // e.g. iOS
{
dbPath = System.IO.Path.Combine(Application.streamingAssetsPath, "Your.xml");
}

Thanks to David I have resolved this problem.
for more precision I add some small details:
1-As David points out in his answer (and as stated in unity documentations), we should use StreamingAssets if we want to have the same folder structure. One should use Application.streamingAssetsPathto retrieve the path.
However, files are still in the apk package in android's case, so they should be accessed using unity android's www class.
a good practice here is to create a method to read the file (even mandatory if you are going to read more than one file)
here is one such method:
private IEnumerator LoadDataFromResources(string v)
{
WWW fileInfo = new WWW(v);
yield return fileInfo;
if (string.IsNullOrEmpty(fileInfo.error))
{
fileContents = fileInfo.text;
}
else
fileContents = fileInfo.error;
}
This is a coroutine, and to use it we need to call it using
yield return StartCoroutine(LoadDataFromResources(path + "/fileName.ext"));
Yet another remark: we can not write into this file or modify it as it's still inside the apk package.

Reading XML config file on run time in a phone gap / cordova application

I was trying to read the xml config file on a phonegap application on runtime: While running on the emulator the config.xml is in the root directory and easily accessable with a get instruction, i can't figure where on the phone this file is stored.
This is the code for reading the XML for retrieving some data directly (for example you can retrieve the version) using angular JS, i just share for anyone may need.
getXmlConfig: function (path) {
var defer = $q.defer();
if (!navigator.platform.match(/Win32|Mac/i)) {
configfilepath = path;
}
else {
configfilepath = "config.xml";
}
getXmlData(configfilepath).success(function (data) {
console.log(data);
var parser = new DOMParser();
var doc = parser.parseFromString(data, "application/xml");
var tagXml = doc.getElementsByTagName("widget");
dataretrieved = tagXml[0].getAttribute('version');
defer.resolve(dataretrieved);
});
return defer.promise;
}
Thanks in advance!

#Alex,
the Cordova/Phonegap file named config.xml is not available once you App has been bundled into an APK(Android) or IPA(iOS). One of the purposes of Cordova/Phonegap is to relieve the programmer from such details.
I am told, if you download you your APK, and change the file name extension to .zip you will see there is NO config.xml in the bundle; in it's place you will find AndroidManifest.xml.

Ok so if it's impossbile with javascript, it can be read by the file plugin!
There is a list of possibile path where the config file is stored, but can't find anything in documentation about.
Android File System Layout
Device Path cordova.file.*
file:///android_asset/ applicationDirectory
/data/data// applicationStorageDirectory
cache cacheDirectory
files dataDirectory
Documents documents
sdcard/ externalRootDirectory
Android/data// externalApplicationStorageDirectory
cache externalCacheDirectory
files externalDataDirectory