file.exists 返回 false xamarin android

Question

i'm trying to use a font file in my Xamarin.android app. I want to use it in itext7 library. but I got exceptions on my setfont function saying that it's empty though I had my font files added to the set so I tried to check if my font file exists using file.exist function. I tried this code:

a = File.Exists("C:/Windows/Fonts/Arial.ttf");
           
            if (a==true)
            {
                Android.App.AlertDialog.Builder alert = new Android.App.AlertDialog.Builder(this);

                alert.SetTitle("exist");

                alert.SetMessage("exists!");
                alert.SetPositiveButton("Okay", (senderAlert, args) =>
                {
                    alert.Dispose();
                });

                _dialog = alert.Create();

                _dialog.Show();
               

            }
            else
            {
                Android.App.AlertDialog.Builder alert = new Android.App.AlertDialog.Builder(this);

                alert.SetTitle("exist");

                alert.SetMessage("doesn't exist!");
                alert.SetPositiveButton("Okay", (senderAlert, args) =>
                {
                    alert.Dispose();
                });

                _dialog = alert.Create();

                _dialog.Show();
            }

the result was that the file doesn't exist. though the physically exits in the mentioned path and it is a font file found in the system it's not a file that I downloaded. I checked the permissions I found that the permission of the directory font is read-only for all the files in it. I tried using other fonts too. I don't understand why is it returning false. thanks in advance

Answer 1

Here is how to integrate fonts into xamarin Android: https://docs.microsoft.com/en-us/xamarin/android/app-fundamentals/resources-in-android/fonts

1. Package the font as an Android resource – this ensures that the font is always available to the application, but will increase the size of the APK.
2. Download the fonts – Android also supports downloading a font from a font provider. The font provider checks if the font is already on the device. If necessary, the font will be downloaded and cached on the device. This font can be shared between multiple applications

The first way is the simplest:

Packaging a font into an Android APK ensures that it is always available to the application. A font file (either a .TTF or a .OTF file) is added to a Xamarin.Android application just like any other resource, by copying files to a subdirectory in the Resources folder of a Xamarin.Android project. Fonts resources are kept in a font sub-directory of the Resources folder of the project.

And if you want to access it in the code:

Android.Graphics.Typeface typeface = this.Resources.GetFont(Resource.Font.caveat_regular);
textView1.Typeface = typeface;
textView1.Text = "Changed the font";