胸腺下拉菜单

Question

我正在尝试在表单中创建下拉列表。我的用户输入的文本输入显示出来，但是，我的枚举下拉列表没有列出值。我知道这里还有其他关于同一主题的帖子（我读过），但似乎仍然无法显示下拉列表。有人能帮我吗？这就是我尝试过的。。。

            <form action="#" th:action="@{${isAdded}?'/save':'/update'}" th:object="${user}" method="post" enctype="multipart/form-data">

                Dropdown for User type or role
                <div class="form-group" >
                    <select th:field="*{type}">
                        <option
                                th:each="type : ${UserType.values()}"
                                th:value="${type}"
                                th:text="${type}">
                        </option>
                    </select>
                </div>


                <div class="form-group">
                    <input type="text", class="form-control" id="firstName" placeholder="First Name" th:field="*{firstName}">
                </div>
.... The remaining text inputs have been omitted...

我还尝试了基于此StackOverflow Post...如何使用Spring和Thymeleaf在下拉列表中显示所有可能的枚举值？

 <div class="form-group" >
                    <select th:field="*{type}">
                        <option
                                th:each="type : ${T(com.abbyhowe.LearnFolio.models.User.type).values()}"
                                th:value="${type}"
                                th:text="${type}">
                        </option>
                    </select>
                </div>

这使下拉列表显示出来，但没有显示类型列表作为可选选项。

<div class="form-group" >
                    <select th:field="*{type}">
                        <option
                                th:each="type : ${types}"
                                th:value="${type}"
                                th:text="${type}">
                        </option>
                    </select>
                </div>

这是我的用户类。

@Entity
@Table(name="user")
public class User implements Serializable {

    /***
     *
     */
    private static final long serialVersionUID = -8885466378515990394L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private Long id;

    @NotBlank(message = "First name is required")
    @Size(min = 2, max = 50, message = "Name must be between 3 and 50 characters")
    @Column(name = "first_name")
    private String firstName;

    @Column(name = "type")
    private UserType type;

这是我的枚举UserType...

public enum UserType {
    TEACHER("Teacher"),
    STUDENT("Student"),
    ADMIN("Account Administrator");

    private final String displayName;

    UserType(String displayName) {
        this.displayName = displayName;
    }

    public String getDisplayName() {
        return displayName;
    }
}

Answer 1

我找到了解决方案

 <form action="#" th:action="@{${isAdd}?'/save':'/update'}" th:object="${user}" method="post" enctype="multipart/form-data">

<!--                Dropdown for User type or role-->
                <div class="form-group" >
                    <select th:field="*{type}">
                        <option
                                th:each="type : ${T(com.abbyhowe.LearnFolio.models.UserType).values()}"
                                th:value="${type}"
                                th:text="${type.displayName}">
                        </option>
                    </select>
                </div>