Question

我有一个combobox.it有类别名称。所以我需要将字符串传递给类别。类别类别=（类别）cmbCategory.getSelectedItem（）;这一行得到错误，说不能将字符串转换为类别类型..

private void btnSaveActionPerformed(java.awt.event.ActionEvent evt) {                                        
    // TODO add your handling code here:
    double amount = Double.parseDouble(txtAmount.getText());
    Expense expense = new Expense();
    expense.setReason(txtReason.getText());
    expense.setAmount(amount);
    DateFormat format = new SimpleDateFormat("MMMM d, yyyy");

    Category category = (Category)cmbCategory.getSelectedItem();
    String startDate = ((JTextField)txtDate.getDateEditor().getUiComponent()).getText();

    try {
        Date date = format.parse(startDate);
        expense.setDate(date);
    } catch (ParseException ex) {
        Logger.getLogger(ExpenseView.class.getName()).log(Level.SEVERE, null, ex);
    }

    expense.setCategory(category);
    ExpenseController.saveExpense(expense);
}

Answer 1

Category.getSelectedItem ();返回String

除非将其分配给类Category的属性，例如name，且类型为string

category.setName(cmbCategory.getSelectedItem());

Answer 2

您似乎正在尝试转换，然后将Category分配给String。

由于Category显然不是Category，也没有实施Category，因此您会收到此例外。

您可以为categoryName类添加一个字符串数据成员，例如Category category = new Category().setCategoryName(cmbCategory.getSelectedItem());，然后按如下所示进行设置：

$('#datepicker2').datepicker('setDate', new Date('<?=$value->fecha_final?>'));

java.lang.ClassCastException：java.lang.String无法强制转换为Category类型

2 个答案: