頁面無法讀取到sec:authorize="isAnonymous()"和sec:authorize="isAuthenticated()"甚至sec標簽頁不做解析。

把thymeleaf-extras-springsecurity4改為thymeleaf-extras-springsecurity5即可

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.thymeleaf.extras/thymeleaf-extras-springsecurity4 -->
        <dependency>
            <groupId>org.thymeleaf.extras</groupId>
            <artifactId>thymeleaf-extras-springsecurity5</artifactId>
        </dependency>
 

 /**定義認證規則*/
    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {

        //super.configure(auth);
        auth.inMemoryAuthentication()
                .withUser("admin").password(passwordEncoder().encode("admin")).roles("VIP1", "VIP2");

    }

springBoot2.1.4版本裏添加thymeleaf-extras-springsecurit