private string[] GetMimeTypes()
{
if (FileTypeFilter.Contains("*"))
{
return(new[] { "*/*" });
}
return(FileTypeFilter
.Select(extension => MimeTypeService.GetFromExtension(extension))
.Distinct()
.ToArray());
}
private string[] GetMimeTypes()
{
if (FileTypeFilter.Contains("*"))
{
return(new[] { "*/*" });
}
List <string> mimeTypes = new List <string>();
using Android.Webkit.MimeTypeMap? mimeTypeMap = Android.Webkit.MimeTypeMap.Singleton;
if (mimeTypeMap is null)
{
// when map is unavailable (probably never happens, but Singleton returns nullable)
return(new[] { "*/*" });
}
foreach (string oneExtensionForLoop in FileTypeFilter)
{
bool unknownExtensionPresent = false;
string oneExtension = oneExtensionForLoop;
if (oneExtension.StartsWith("."))
{
// Supported format from UWP, e.g. ".jpg"
oneExtension = oneExtension.Substring(1);
}
if (!mimeTypeMap.HasExtension(oneExtension))
{
// when there is unknown extension, we should show all files
unknownExtensionPresent = true;
}
string?mimeType = mimeTypeMap.GetMimeTypeFromExtension(oneExtension);
if (string.IsNullOrEmpty(mimeType))
{
// second check for unknown extension...
unknownExtensionPresent = true;
}
else
{
#pragma warning disable CS8604 // Possible null reference argument.
// it cannot be null, as this is within "if", but still compiler complains about possible null reference
if (!mimeTypes.Contains(mimeType))
{
mimeTypes.Add(mimeType);
}
#pragma warning restore CS8604 // Possible null reference argument.
}
if (unknownExtensionPresent)
{
// it is some unknown extension
var mimeTypesFromUno = FileTypeFilter
.Select(extension => MimeTypeService.GetFromExtension(extension))
.Distinct();
if (mimeTypesFromUno is null || mimeTypesFromUno.Count() < 1)
{
return(new[] { "*/*" });
}
foreach (var oneUnoMimeType in mimeTypesFromUno)
{
if (!mimeTypes.Contains(oneUnoMimeType))
{
mimeTypes.Add(oneUnoMimeType);
}
}
}
}
return(mimeTypes.ToArray());
}