Android Question About SendMessage and SendKeys

[Im Blind]

Hi.
I Cant Speak English Well But I Have a Question.
Im C# Programmer and now i will Learn Android Programming.
I Will Know What is Like SendMessage Or SendKeys Of C# in B4A
So That in Windows Just Need Handle Of any Form To Send Any Thing Out of That Program
For Example i will Send a text Message to Whats app from my created application (not using Share via...)
Or Any Where i Focused , My Text Put there .
Please help me
im sorry if i have misspell

an application in C# that send an key any where you focused !
using System;
class SendKeyS
{
static void Main()
{

//-------------before start application i will focuse on a text box!
System.Threading.Thread.Sleep(5000); // ------------5 second to click any where
SendKeys("its Test");
}
}

 

[Im Blind]

im sorry its my first post i dont know what should i ask my question ! :|

 

[Erel]

There is no equivalent API in Android. You cannot send key presses to other apps.