android - How can I share text in what's app on particular Number -

using code open particulat number's chat text not share.how can this?

public class mainactivity extends appcompatactivity { button wa; string id = "+919000000000"; edittext txt;  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);     txt = (edittext)findviewbyid(r.id.edittext);     wa = (button)findviewbyid(r.id.btn_whatsapp);     wa.setonclicklistener(new view.onclicklistener() {         @override         public void onclick(view v) {             uri uri = uri.parse("smsto:" + id);             intent waintent = new intent(intent.action_sendto,uri);              string text = "testing message";             waintent.setpackage("com.whatsapp");             if (waintent != null) {                 waintent.putextra(intent.extra_text, text);                 startactivity(intent.createchooser(waintent, text));             } else {                 toast.maketext(getapplicationcontext(), "whatsapp not found", toast.length_short)                         .show();             }           }     });  } 

since trying achieve "smsto:", "text/plain" type you. try "sms_body" if won't help.

uri uri = uri.parse("smsto:" + id); intent waintent = new intent(intent.action_sendto,uri); string text = "testing message"; waintent.setpackage("com.whatsapp"); if (waintent != null) {     waintent.settype("text/plain");     //waintent.putextra(intent.extra_text, text);     waintent.putextra("sms_body", text);      startactivity(intent.createchooser(waintent, text)); } else {     toast.maketext(getapplicationcontext(), "whatsapp not found", toast.length_short)             .show(); }