エラー処理

// エラー処理
/* 1. setError
2. Toast
3. Dialog */

myEditText.setError("エラー");

Toast.makeText( this, "エラー", Toast.LENGTH_LONG ).show();

AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this); alertDialogBuilder .setTitle("Error!") .setMessage("エラー") .setPositiveButton("OK", null); AlertDialog alertDialog = alertDialogBuilder.create(); alertDialog.show();