android - Type mismatch: cannot convert from void to Integer -

i have t1 text view. want store value of t1 in variable getting "type mismatch: cannot convert void integer" error

integer res=t1.settext(integer.tostring(result));

you can use see value

t1.settext(integer.tostring(result));  string result= t1.gettext().tostring(); 

and if want alert result:

new alertdialog.builder(this)     .settitle("result")     .setmessage("this textview value : "+ result)     .setpositivebutton(android.r.string.yes, new dialoginterface.onclicklistener() {         public void onclick(dialoginterface dialog, int which) {              // can want when user press yes         }      })     .setnegativebutton(android.r.string.no, new dialoginterface.onclicklistener() {         public void onclick(dialoginterface dialog, int which) {              //  can want when user press no         }      })     .seticon(r.drawable.ic_dialog_alert)      .show();