AppCreator | 一个安卓上的安卓开发环境

Hello I am creating a unit converter app trying to self learn on how to make android apps how can make my app show a message instead of crashing when clicking the convert button here are my codes if input is nothing or "."

Personaly I am thinking of disabling the button if there is not input in the fromEditText.

XML

i have spring boot application that i want to package to jar. On run my application "java -jar app.jar" i caught error "Could not find or load main class com.software.appcreator.MyClass". I use gradle to build app, here is details of my build.gradle file(without dependencies):

https://pastebin.com/MvNgBDua

there are problems with formatting build.gradle, therefore posted on pastebin

what could be the reason for this situation? i pointed out main class in config and MyClass is present in final jar

It seems I'm on a journey to first programmatically create an Azure application and then use Azure Management APIs to do create some resource. There's a new snag I'd like to ask from the community, how to do basically the PowerShell command New-AzureRmRoleAssignment -RoleDefinitionName Owner -ServicePrincipalName $adApp.ApplicationId.Guid using HttpClient (or some smarter method with the exact needed permissions using Microsoft Graph API libraries).

Trying to be a better person this time (being more around, providing code), I prepared a repo in GH, but the issue basically boils down to what kind of a URI should be used (here). The code is