十天冲刺（第一阶段）

今天学习了相关的数据库操作以及页面的跳转实验了一下再界面上简单的输出一下所求的数据，为下一步整合数据进行相关操作做铺垫：，比原生的一些东西要好用效率高太多

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.si_fragment,container,false);

        mDatabaseHelper = new DatabaseHelper(getActivity());
        mCostBeanList = new ArrayList<>();
         mTextView = view.findViewById(R.id.textView);
         button = view.findViewById(R.id.button2);
         editText = view.findViewById(R.id.editText2);
         button.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                 String i = editText.getText().toString();
                 Cursor cursor =mDatabaseHelper.selectlist(i);
                 if (cursor != null){
                     while (cursor.moveToNext()){
                         CostBean costBean = new CostBean();
                         costBean.costTitle = cursor.getString(cursor.getColumnIndex("cost_title"));
                         costBean.costDate = cursor.getString(cursor.getColumnIndex("cost_date"));
                         costBean.costMoney = cursor.getString(cursor.getColumnIndex("cost_money"));
                         mCostBeanList.add(costBean);

                     }
             }
                 String s = "";
                 for(int j = 0;j<mCostBeanList.size();j++){
                     s += mCostBeanList.get(j).getCostTitle();
                 }
                 mTextView.setText(s);
             }
         });
        return view;
    }