两种小提示信看

第一种:

 Toast.makeText(Calculator.this
, 
"The buttonface was 1."
, Toast.LENGTH_SHORT).show();

第二种

 private
 
void
 openOptionsDialog() {
     new
 AlertDialog.Builder(
this
)
     .setTitle("weight / (height * height) is :"
 + BMI)
     .setMessage("Android BMI Calc"
)
     .show();
 }

   openOptionsDialog();