Develop Reference

How to find path of file in MAUI for all platforms?

I'm making an app that I want to export to both Windows and Android. In this piece of code, I'm trying to read from a .csv file:
using (StreamReader csv = new StreamReader("MOCK_EMPLOYEE_DATA.csv"))
However, It keeps giving me an error that the file was not found and the path was incorrect. What is the best way to go about this?
The file is in my project folder.

You could do that by following these steps:
1.Drag or add the csv file to the Project.
2.Set the Build Action of csv file to MauiAsset.
3.use the following code to read the file:
using var stream = await FileSystem.OpenAppPackageFileAsync("File.csv");
using var reader = new StreamReader(stream);
var contents = reader.ReadToEnd();
Console.WriteLine(contents);
Hope it works for you.

How do I get the directory for the app itself in xamarin.forms

I have a .txt file in a Resources folder that I created in the Xamarin.Forms project for the app (not the Android or iOS versions), and I want to know how to access that file as soon as the app loads. I tried just creating a StreamReader with the path "Resources/tips.txt" ("tips" is the name of the file), but that doesn't work because apparently, the current directory at that point is nothing. How do I get the directory of the app itself so I can access that folder?

Resources aren't files, you don't use file paths to access them
// MyClass is a class in the same assembly as your resource
var assembly = IntrospectionExtensions.GetTypeInfo(typeof(MyClass)).Assembly;
// see linked docs for notes about resource naming
Stream stream = assembly.GetManifestResourceStream("MyResourceName");
string text = "";
using (var reader = new System.IO.StreamReader (stream))
{
text = reader.ReadToEnd ();
}

Getting the contents of a file in Visual Studio without opening the file from an extension

I'm trying to read the contents of a file in a Visual Studio extension. The following code works, but forces me to open the file, if it isn't (otherwise it crashes):
textDocument = (TextDocument)projectItem.Document.Object("TextDocument");
EditPoint editPoint = textDocument.StartPoint.CreateEditPoint();
string text = editPoint.GetText(textDocument.EndPoint);
I can get the path of the project, so I suppose I could make an educated guess as to the location of the project item. However, ideally I'd like to either get the file contents without opening it; or, alternatively, get the path to the project item (then I could just use System.IO to access the file contents).
I've looked, but don't seem to be able to find any mention of either of these. Can anyone point me in the right direction, please?

You can get the path from a ProjectItem by reading its properties.
var path = YourProjectItem.Properties.Item("FullPath").Value.ToString()
After you have the path you can read its content with System.IO.
string content = File.ReadAllText(path);
If the file is somewhat larger and you are getting troubles with the current code due to size, you should take a look at the StreamReader class.

I'm not sure if this is possible for extensions but you could probably use System.IO, like this:
using System.IO;
string filePath = #"C:\Whatever\YourFileName.txt";
string fileText = File.ReadAllText(filePath);
You could also use StreamReader like this:
using System.IO;
string filePath = #"C:\Whatever\YourFileName.txt";
using (StreamReader sr = new StreamReader(filePath))
fileText = sr.ReadToEnd();
EDIT:
I think I understand you better now.
The only way to "get the file contents without opening it" would be if the extension were to give you that data actively, but I can safely assume it doesn't.
When reading a file, you should already know where the file is (if you don't know then either you're not intended to access that file or you just haven't looked long enough).
I'd try searching the SDK files manually (Or with a file crawler).

Android text file not found

I have a text file in my solution called "txtWords.txt", which I attempt to read with:
string path = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
string filePath = Path.Combine(path, "txtWords.txt");
In my experimenting, I've got the same file under both my C# App and the App.Android > Assets folder (set to AndroidAsset). I thought to put it in both locations to be safe.
System.IO.FileNotFoundException: Could not find file "/data/user/0/com.WSC/files/txtWords.txt"
I've read about using AssetManager but that gives me a "namespace could not be found error".
What am I doing wrong and what's the best way to read a text file for an app? This should be really easy so I'm doing something fairly basic wrong, I suppose.

Using Xamarin Essentials you can read a bundled/asset read-only file via your NetStd (Xamarin.Forms) library:
string wordsText;
using (var stream = await FileSystem.OpenAppPackageFileAsync("txtWords.txt"))
using (var reader = new StreamReader(stream))
{
var wordsText = await reader.ReadToEndAsync();
}
re: https://learn.microsoft.com/en-us/xamarin/essentials/file-system-helpers?tabs=android
Nuget: https://www.nuget.org/packages/Xamarin.Essentials

Referencing a file inside of a Project without using its absolute path?

I'm using StreamReader to dynamically replace content in an HTML template. The HTML file has been imported into my project.
Right now I'm having to referencing the HTML file a static location on my dev box because I'm not able to find the right syntax to reference it once it's been imported into my VS project.
How do I refer to the file without using an absolute path?
Current implementation for reference:
StreamReader reader = new StreamReader(#"C:\Users\n00b\Desktop\EmailTemplate.html");
{
body = reader.ReadToEnd();
}

One common thing I've seen is to put the file's location in a configuration file. This lets you change the file location at will without having to recompile.

You can add it as an embedded resource and extract it this way.
using (Stream stream = System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream("<namespace>.Resources.EmailTemplate.html"))
per your comment
using (System.IO.StreamReader sr = new StreamReader(System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream("<namespace>.Resources.EmailTemplate.html"))
{
body = sr.ReadToEnd();
}

There are 2 main ways to do this, In a desktop application, the current directory of the .exe is set to the directory where it is launched from by default. Unless that is changed by launching the .exe by a shortcut with special settings, or by another process using a special feature, it should be the default value. If that is the case, you can just use a relative path. For example, if you have a file named "data.txt" in a folder called "things" inside a folder called "stuff" in the same directory as your app, you can just us the relative path "stuff/things/data.txt" directly and Windows will work it out for you.
If you need to be absolutely sure you are targeting that file, even if the app launches with a modified current directory, you can get the .exe's path, and combine it with a relative path using System.IO.Path.Combine.
var appPath = Assembly.GetEntryAssembly().Location;
var filePath = "stuff/things/data.txt"
var fullPath = System.IO.Path.Combine(appPath, filePath)
If, for some reason, you need to up "up" from the application's directory, you can use ".." to represent that parent folder of a directory. So "../data.txt" would look in the folder that contains the current directory for a file named "data.txt".
You could also change the app's current directory when it starts to be the directory of the .exe, and then reference everything via relative path, as in the first example.
var appPath = Assembly.GetEntryAssembly().Location;
System.IO.Directory.SetCurrentDirectory(appPath);

I found two solutions to this:
If you don't care if the external file is visible in the build directory/installdir of your app:
StreamReader reader = new StreamReader(#"../../EmailTemplate.html");
{
body = reader.ReadToEnd();
}
If you want your external file to be invisible once compiled:
var embeddedResource = "<namespace>.EmailTemplate.html";
using (var stream = Assembly.GetExecutingAssembly().GetManifestResourceStream(embeddedResource))
{
StreamReader sr = new StreamReader(stream);
body = sr.ReadToEnd();
}
Note the 2nd solution requires adding your external file and changing the build action to "Embedded Resource" on the properties menu of that file within Visual Studio.