Since I found some older posts, that tell that whatsapp doesn\'t support this, I was wondering if something had changed and if there is a way to open a whatsapp \'chat\' wit
I'm really late here but I believe that nowadays we have shorter and better solutions to send messages through WhatsApp.
You can use the following to call the system picker, then choose which app you will use to share whatever you want.
Intent sendIntent = new Intent();
sendIntent.setAction(Intent.ACTION_SEND);
sendIntent.putExtra(Intent.EXTRA_TEXT, "This is my text to send.");
sendIntent.setType("text/plain");
startActivity(sendIntent);
If you are really need to send through WhatsApp all you need to do is the following (You will skip the system picker)
Intent sendIntent = new Intent();
sendIntent.setAction(Intent.ACTION_SEND);
sendIntent.putExtra(Intent.EXTRA_TEXT, "This is my text to send.");
sendIntent.setType("text/plain");
// Put this line here
sendIntent.setPackage("com.whatsapp");
//
startActivity(sendIntent);
If you need more information you can find it here: WhatsApp FAQ