错误：未经检查的调用DefaultComboBoxModel（E []）

Question

当我构建/运行我的applet时，从NetBeans Applet表单中获取了2个错误：

warning: [unchecked] unchecked call to DefaultComboBoxModel(E[]) as a member of the raw type DefaultComboBoxModel
        levelBox.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "1", "2", "3", "4", "5", "6", "7" }));
  where E is a type-variable:
    E extends Object declared in class DefaultComboBoxModel
warning: [unchecked] unchecked call to setModel(ComboBoxModel<E>) as a member of the raw type JComboBox
        levelBox.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "1", "2", "3", "4", "5", "6", "7" }));
  where E is a type-variable:
    E extends Object declared in class JComboBox
2 warnings

如果我点击下拉列表，我会在旁边看到一个惊叹号。那是为什么？

此外，这是使用“-Xlint：unchecked”选项。

Answer 1

new javax.swing.DefaultComboBoxModel(new String[]

应替换为

new javax.swing.DefaultComboBoxModel<String>(new String[]

此警告也可以忽略。