Question

我坚持使用我的应用程序的最后一件事。当按下按钮bSubmit时，所有的功能都工作，除了在EditText框中没有给出输入时强制关闭，而不是强制关闭，我试图放一个toast msg，这也不起作用。我想我的逻辑存在缺陷

if (v.getId() == R.id.bSubmit) {

        String numstr = numberEditText.getText().toString();
        String pontstr = pointEditText.getText().toString();
        int point = Integer.parseInt(pontstr);
        //takes in the customer's number and the purchase amount

        //search for the customer's number in database
        DatabaseHelper helper = new DatabaseHelper(this);
        Log.d("onButtonClick",""+numstr);
        customer = helper.searchCustomer(numstr);



        if (numstr.equals(null) || pontstr.equals(null)){
            Context toastcontext = getApplicationContext();
            CharSequence text ="You haven't put any value";
            int duration = Toast.LENGTH_SHORT;


            Toast toast = Toast.makeText(toastcontext,text, duration);
            toast.show();

        }



        if (customer.getuNum() != null && customer.getuNum().equals(numstr)) {

            //if found then add the amount as new points
            //int row = helper.searchRow(customer.getuNum());
           // int point = helper.searchPoint(customer.getuNum());
            int pnt =  customer.getPoint() + point;
            Log.d("MainActivity",customer.getuNum()+" pnt "+pnt);
            helper.updatePoint(pnt,customer.getuNum());
            currentPoint.setText("Your point is "+pnt);
        }

        else {

            //create a new customer and add the info to database
            Customer customer = new Customer();
            customer.setuNum(numstr);
            customer.setPoint(point);
            helper.insertCustomer(customer);
            Log.d("MainActivity","customer null num "+customer.getuNum()+" point "+point);
            currentPoint.setText("Your point is " + point);
        }

        numberEditText.getText().clear();
        pointEditText.getText().clear();
    }

Answer 1

如果输入不是整数，则

int point = Integer.parseInt(pontstr);将抛出NumberFormatException（如果在EditText中没有任何内容，则为空字符串""，或者除了整数之外的任何内容）值）。这会导致您正在谈论的无声崩溃。

我的建议是用try-catch块围绕你的parseInt()调用，并处理调用会抛出NumberFormatException的情况。像这样：

int example; try { example = Integer.parseInt(pontstr); } catch (NumberFormatException e) { // Logic to deal with invalid input, maybe toast the user. }

Answer 2

如果您的字符串不是数字，您将获得数字格式异常。您需要在空检查通过后放置语句。
您正在以错误的方式进行检查。

if（numstr.trim（）。isEmpty（）|| pontstr.trim（）。isEmpty（）{ Context toastcontext = getApplicationContext（）; CharSequence text =＆＃34;你没有放任何价值＆＃34 ;; int duration = Toast.LENGTH_SHORT;
```
        Toast toast = Toast.makeText(toastcontext,text, duration);
        toast.show();

    }
```

我希望这会有所帮助。

有缺陷的＆＃34;或逻辑＆＃34;在onButtonClick导致力量关闭

2 个答案: