Xamarin Launcher.OpenAsync "request url too long"

Issue

I am trying to send an image (it can't be a file, must be a base64) to another app using the URI scheme and the Xamarin Launcher.

var uri = new Uri(url);  
await Launcher.OpenAsync(uri); // await Launcher.OpenAsync(url);

Both: new Uri(url) and await Launcher.OpenAsync(url) give an exception if the url lenght is over 2000 characters.

As I know, passing base64 strings to other apps (for example to edit an image or print a document) is normal. So why does Xamarin limit it to 2000 characters?

Is there a workaround?

Edit:
Exception on new Uri:

System.UriFormatException: Invalid URI: The Uri string is too long.
  at System.Uri.CreateThis (System.String uri, System.Boolean dontEscape, System.UriKind uriKind) [0x0007b] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/referencesource/System/net/System/UriExt.cs:55 
  at System.Uri..ctor (System.String uriString) [0x00014] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/referencesource/System/net/System/URI.cs:408 

Exception on Launcher.OpenAsync:

System.UriFormatException: Invalid URI: The Uri string is too long.
  at System.Uri.CreateThis (System.String uri, System.Boolean dontEscape, System.UriKind uriKind) [0x0007b] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/referencesource/System/net/System/UriExt.cs:55 
  at System.Uri..ctor (System.String uriString) [0x00014] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/referencesource/System/net/System/URI.cs:408 
  at Xamarin.Essentials.Launcher.OpenAsync (System.String uri) [0x00013] in D:\a\1\s\Xamarin.Essentials\Launcher\Launcher.shared.cs:32 

Solution

It seems that this is the limitation of System.Uri class. While it is not officially documented if you search you will find this being discussed on many places like here: https://social.msdn.microsoft.com/forums/en-US/6435996c-4b96-4887-be60-f6e10120f0a0/long-http-get-requests-and-a-uri-max-length-constraint

Basically you have to use the native classes to achieve what you want.

Answered By - Ivan Ičin