AlertDialog的基本使用

FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
LayoutInflater inflater = LayoutInflater.from(MainActivity.this);
View viewDialog = inflater.inflate(R.layout.new_cost, null);
builder.setTitle("new Cost");
builder.setView(viewDialog);
final EditText et_title = (EditText) viewDialog.findViewById(R.id.et_title);
final EditText et_money = (EditText) viewDialog.findViewById(R.id.et_money);
final DatePicker dp = (DatePicker) viewDialog.findViewById(R.id.date);
//builder.setPositiveButton("确认", null);
builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
String title = et_title.getText().toString();
String money = et_money.getText().toString();
String date = dp.getYear() + "-" + (dp.getMonth()+1) + "-" + dp.getDayOfMonth();

CostBean costBean = new CostBean(title,date,money);
helper.insert(costBean);
list.add(costBean);
adapter.notifyDataSetChanged();
}
});
builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {

}
});
final AlertDialog alertDialog = builder.create();
alertDialog.show();
//                alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setOnClickListener(new View.OnClickListener() {
//                    @Override
//                    public void onClick(View v) {
//                        String title = et_title.getText().toString();
//                        String money = et_money.getText().toString();
//                        String date = dp.getYear() + "-" + (dp.getMonth()+1) + "-" + dp.getDayOfMonth();
//                        if (title.isEmpty()){
//                            Toast.makeText(MainActivity.this,"请输入消费条目",Toast.LENGTH_LONG).show();
//                            return;
//                        }
//                        if (money.isEmpty()){
//                            Toast.makeText(MainActivity.this,"请输入消费金额",Toast.LENGTH_LONG).show();
//                            return;
//                        }
//
//                        CostBean costBean = new CostBean(title,date,money);
//                        helper.insert(costBean);
//                        list.add(costBean);
//                        adapter.notifyDataSetChanged();
//                        alertDialog.dismiss();
//                    }
//                });

}
});