Develop Reference

Xamarin.essentials FilePicker copies selected external file to cache folder

For the last 2 weeks I've been successfully converting a WPF application to a Xamarin.forms android app. Everything works as intended except for 1 thing. I've been searching the web for a few days for a solution but I can't find a working solution.
This is my current setup:
Xamarin.Froms android app
Target android version: Android 10.0
Minimum android version: Android 7.0
Xamarin.Essentials version: 1.6.0
READ_EXTERNAL_STORAGE permission
WRITE_EXTERNAL_STORAGE permission
My app should be able to open a selected file, using the Xamarin.Essientials FilePicker, Do some stuff and save the File again to the same path. The file selection is handled in the following code:
var pickresult = await FilePicker.PickAsync();
if (pickresult != null)
{
try
{
var result = await pickresult.OpenReadAsync();
var reader = new StreamReader(result);
var jsonstring = reader.ReadToEnd();
ConfigData = JsonConvert.DeserializeObject<ProjectData>(jsonstring);
PLC_Data.ProjectLoaded = true;
L_LoadedProject.Text = pickresult.FileName;
ProjectData.Filepath = pickresult.FullPath;
reader.Close();
result.Close();
//Load login page
B_Next.IsEnabled = true;
}
This is where the problem occurs. Let me clearify what happens step by step:
The FilePicker opens a File picking window.
I navigate to my preferred file in the "download" folder, could be any folder.
The file is read and converted to an object
The file path is saved
when i check the filepath i get the following string:
"/storage/emulated/0/Android/data/com.FAIS.motorconfigapp/cache/2203693cc04e0be7f4f024d5f9499e13/303bc84665374139b6303c03255e9018/config1.json"
So the FilePicker copies the "External" file to the App cache folder and returns the filepath from the Apps cache folder. When i check this folder there is indeed a copy of my selected file inside it. Reading from and writing to this file works as it should.
Now the actual question:
Why does the FilePicker copy my selected file to his cache folder and how can i prevent it?
The user should be able to select a file from anywere on the device and find the updated file in the same location.
I've checked all my settings and in my opinion everyting should be correct so i don't get why a copy is created. Does anyone have an idea?
If you need more settings, pictures, versions please ask.
Thanks in advance

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");

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.

Titanium 3.X getFile() from local storage

Using Titanium on Android 4+ I want to access a jpeg file which has been taken with the camera. I need to achieve 2 objectives, namely, return the EXIF data and transfer the bytes to an API endpoint. My problem is I'm unable to access the file...
I'm using a 3rd party module to handle the file selection (Multi Image Picker) which returns a list of file locations, using the File Manager app on the emulator (GenyMotion) I can confirm the location on disk is correct. However, the following always returns false...
var file = Ti.Filesystem.getFile('/mnt/sdcard/DCIM/Camera/IMG_20140901_083735.jpg');
Ti.API.info('Do we have a file? ' (file.exists()? 'YES' : 'NO'));
The output for the above would be... Do we have a file? NO
Further reading shows Titanium has 5 predefined folder locations which can be passed into the getFile() method and one possible reason for the above code not working would be it is defaulting to the 'Resouces' folder location? That said all but one folder location is app specific, the exception being externalStorageLocation. Now my understanding of an Android device is that any image taken with the camera will be stored on the internal storage system unless an SD card is present. This is true in my case as the following lists 0 files...
var extDir = Ti.Filesystem.getExternalStorageDirectory();
var dir = Ti.Filesystem.getFile(extDir);
var dir_files = dir.getDirectoryListing();
Ti.API.info('External files... ' + dir_files.length);
The output for the above would be... External files... 0
So am I right in thinking Appcelerator have simply not included the ability to access local storage (outside of any app specific folders) within their API? Or am I missing something and there is in fact another way?

Thanks to #Bharal I was able to find a solution...
By using the Ti.Media.openPhotoGallery() method I was able to identify the correct native path for the image by inspecting the event object returned from the success callback.
The path was missing 'file://' at the beginning, I couldn't be 100% sure but I suspect this forces the getFile() method to use an absolute path and not a relative path from within the Resources folder.
To confirm, the following will return a file object...
var file = Ti.Filesystem.getFile('file://[path]');
Where [path] is the folder location as reported within the File Manager app on the device, for example '/mnt/sdcard/DCIM/Camera/IMG_20140901_083735.jpg'

Yah mon, i dunno.
Here is wat i used when i was doin pictures on my Ti app, but then i got rid of that section because i realised i didn't need to be doin pictures. Pictures mon, dey ain' what you want sometimes, yo?
Ti.Media.openPhotoGallery({ //dissall jus' open up a piccha selectin' ting. ez.
success:function(event){
var image = event.media;
if (event.mediaType==Ti.Media.MEDIA_TYPE_PHOTO){
//so image.nativePath is the path to the image.
// profileImg be jus' some Ti.UI.createImageView ting yo be puttin in yo' page.
//meyybe yo be wantin' alert(image.nativePath); here too, dat be helpin?
profileImg.image = image.nativePath;
}
},
cancel:function(){
//we cancelled out, why we doin' that?
}
});
Now that isn't going to really be helpin' you, but yo can use that to see wat the native path yo piccha be usin' be, and then be seein' if maybe what yo be puttin' in yo code be sam ting.
Jus' wrap the above as an addEventListener("click", function(){ ... } ); on sam ting in yo page, and jus' add sam element to put th' piccha in if yo be wantin' to see the piccha but i be tellin' you picchas mon, sometimes dey ain' worth time.
But meyybe yo wantin' use not an emulator for dis ting, dey can be actin' weird yo should be usin some small phone maybe? Dat way you can be findin' if yo got dem memory leeks and meyybe some memory sprouts, an memory onions too.

Load an external text. Works on my computer, but not on app

I'm creating an app for Air 3.8 on Flash CS6. When I click on info_btn, the programm load an external textfile (here test.txt) and shows it in my dynamic text field (here info_txt).
It works when I CRTL+Enter, but not on my android device when I test the .apk file I created. I'm sure the reason is that the test.txt is not compiled in the apk, but I don't know how to change that. If you guys can help, it would be great.
Here is my code, if it can help:
var fl_TextLoader_3:URLLoader = new URLLoader();
var fl_TextURLRequest_3:URLRequest = new URLRequest("textes/test.txt");
fl_TextLoader_3.addEventListener(Event.COMPLETE, fl_CompleteHandler_3);
function fl_CompleteHandler_3(event:Event):void
{
var textData:String = new String(fl_TextLoader_3.data);
info_txt.text = textData;
}
info_btn.addEventListener(MouseEvent.CLICK, fl_infotxt);
function fl_infotxt(Event:MouseEvent):void {
fl_TextLoader_3.load(fl_TextURLRequest_3);
}

Usually mobile AIR projects will have an assets folder -- they do in Flash Builder and Flash Develop IDEs, so I assume CS6 has something similar.
The assets folder is where images and app icons go that will be delivered in the .apk. You can put any files and folders you want in there, including your text files. To package your text file into the .apk, you could create a assets/textes folder and put your test.txt in it.
Then the URL you would need in your code would be:
var fl_TextURLRequest_3:URLRequest = new URLRequest("assets/textes/test.txt");