Question

对java swing gui进行了一些错误检查，我正在尝试完成类的分配。需要检查的部分是用户在计算之前输入比萨数量和苏打数量的数字。我想让程序做的是检测一个空格并提供一个弹出窗口，告诉用户该空格是空白的，需要一个0-100的数字。我正在寻找它做任何事情，但崩溃或提供例外。一旦我们弄清楚错误检查，我就会担心弹出文本。非常感谢任何和所有帮助.......

private void btnCalcActionPerformed(java.awt.event.ActionEvent evt) {                                        
    final double LOCAL_TAX = .02;
    final double STATE_TAX = .06;
    NumberFormat nf = NumberFormat.getCurrencyInstance();

    int intPizza = Integer.parseInt(qtyInputPizza.getText());
        while (!intPizza.hasNextInt(101))
            {

            }
    int intSoda = Integer.parseInt(qtyInputSoda.getText());

    double dblPizzaSub = intPizza * PIZZA_PRICE;
    double dblSodaSub = intSoda * SODA_PRICE;

    pizzaSubtotal.setText(nf.format(dblPizzaSub));
    sodaSubtotal.setText(nf.format(dblSodaSub));

    double dblNetSale = dblPizzaSub + dblSodaSub;
    netSaleValue.setText(nf.format(dblNetSale));

    double dblStateTax = dblNetSale * STATE_TAX;
    double dblLocalTax = dblNetSale * LOCAL_TAX;
    stateTaxValue.setText(nf.format(dblStateTax));
    localTaxValue.setText(nf.format(dblLocalTax));

    double dblTotalSale = dblNetSale + dblStateTax + dblLocalTax;
    totalSaleValue.setText(nf.format(dblTotalSale));

    btnClear.requestFocusInWindow();
}

Answer 1

替换此行：

int intPizza = Integer.parseInt(qtyInputPizza.getText());

通过

String strPizza = qtyInputPizza.getText();
int intPizza = 0;
if ( strPizza == null || strPizza.trim().length() == 0 ) {
  // Display your error message
}
else
{
 // You can add a test to make sure it is an int not something else
 ntPizza = Integer.parseInt( strPizza  );
}

Java gui空白空间错误检查

1 个答案: