根据用户输入设置枚举

Question

选择 java 备份并尝试熟悉枚举类型。我正在尝试创建一个地址簿，用户可以在其中创建联系人。我已经创建了所有内容，但挂断了设置联系人类型（家庭、朋友、企业等...）我在单独的 java [= 中设置了一个枚举 class 25=]。

public class ContactType
{
    public enum contactType
    {
        Family,
        Church,
        Friend,
        BusninessColleague,
        ServicePerson,
        Customer,
        Other
    }
}

我的联系人 class 看起来像：

public class Contacts
{
        private contactType contact;
    private String name;                    
    private String streetAddress;           
    private String city;                    
    private String state;                   
    private String zipCode;                 
    private String phone;                   
    private String email;                   
    private String photo;                   


    public Contacts ( )
    {
        contact = null;
        name = "XXX XXX";
        streetAddress = "XXX";
        state = "XX";
        zipCode = "00000";
        phone = "XXX-XXXX";
        email = "XXX@XXX.COM";
        photo = "XXX.jpg";
    }


    public Contacts (ContactType contactType, String name, String streetAddress, String city,
                        String state, String zipCode, String phone, String email, String photo)
    {

        this.contact = contactType;
        this.name = name;
        this.streetAddress = streetAddress;
        this.city = city;
        this.state = state;
        this.zipCode = zipCode;
        this.phone = phone;
        this.email = email;
        this.photo = photo;
    }



    public ContactType getContactType ( )
    {
        return contact;
    }


    public void setContactType (ContactType input)
    {
        this.contact = input;
    }

  //rest of code

最后是我的驱动程序，它包含一个菜单（除了设置联系人类型之外其他一切都有效，所以为了保持简短我只包含了该片段）：

switch (iSelection)
  {
    case 1: 
          c1 = new Contacts();      //creates a new contact
          break;
    case 2:
          strContactType = JOptionPane.showInputDialog ("Please enter contact type (Family, Church, BusinessColleague, ServicePerson, Customer, or Other)");
          contactType.valueOf(strContactType);
          JOptionPane.showMessageDialog (null, strContactType);
          c1.setContactType (strContactType);
          break;

我知道我在这里做错了 c1.setContactType(strContactType); 因为我完全不知道 "The method setContactType(ContactType) in the type Contacts is not applicable for the arguments (String)" 我不知道如何修复它以将 contactType 设置为任何用户输入。

Answer 1

您的问题是您调用了 valueOf(...) 但您丢弃了此方法调用返回的 ContactType 对象....即，您从未将返回的对象分配给变量。

首先通过改变这个来摆脱你不必要的包装：

public class ContactType
{
    public enum contactType
    {
        Family,
        Church,
        Friend,
        BusninessColleague,
        ServicePerson,
        Customer,
        Other
    }
}

对此：

    public enum ContactType
    {
        Family,
        Church,
        Friend,
        BusninessColleague,
        ServicePerson,
        Customer,
        Other
    }

接下来使用 valueOf 设置 ContactType 变量。

      strContactType = JOptionPane.showInputDialog ("Please enter contact type (Family, Church, BusinessColleague, ServicePerson, Customer, or Other)");
      ContactType contactType = ContactType.valueOf(strContactType);
      JOptionPane.showMessageDialog (null, strContactType);
      c1.setContactType (contactType);

请注意，我会尝试通过将选择限制为 ContactType 来使其更加安全。例如：

  Object selection = JOptionPane.showInputDialog(null,
        "Choose a contact type", "Contact Type",
        JOptionPane.INFORMATION_MESSAGE, null,
        ContactType.values(), ContactType.values()[0]);

  // check that selection is not null before using
  System.out.println(selection);

Answer 2

调用 ContactType.valueOf(strContactType) 将字符串名称转换为枚举值

根据用户输入设置枚举

Setting an enum from user input

java

enums