External storage in xamarin forms

Question

Im trying to create an excel file in xamarin forms, populate the file with some user generated data and save that excel file on the user's device so that they can share it with other applications(in my case google drive).

I have checked out microsoft's documentation but it did not really help.

Here is the path im using:

  string filepath =  System.Environment.GetFolderPath(Environment.SpecialFolder.Personal);

also tried

string filepath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);

but when i execute the program it breaks and says access to path denied.. Ive searched the error multiple times but could not find a solution that worked for me. and yes i have enabled read and write to external storage premissions. Please help me. also if anyone has advice for create excel files in xamarin that would help

Answer 1

Xamarin.Essentials provides the ability to check and request runtime permissions. You do not to ask for the runtime permission again. Check the MS docs. https://learn.microsoft.com/en-us/xamarin/essentials/permissions?tabs=ios

I tested with the Xamarin.Essentials 1.6.1.

//write

 string text = "12345";
        var path = Path.Combine(System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal), "excel.xlsx");
        using (var writer = File.CreateText(path))
        {
            await writer.WriteLineAsync(text);
        }

//read

 public async Task<string> ReadAsync()
    {
        var backingFile = Path.Combine(System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal), "excel.xlsx");

        if (backingFile == null || !File.Exists(backingFile))
        {
            return null;
        }

        var text = string.Empty;
        using (var reader = new StreamReader(backingFile, true))
        {

            var str = await reader.ReadToEndAsync();

            text = str;

        }

        return text;
    }