解决了 课堂选择角色后，一直停留在自动登录的原因

client/mobile/components/Classroom/useClassroom.ts

@@ -420,7 +420,7 @@ export const useClassroom = () => {
   };
 
   // 课堂操作方法
-  const login = async (userId: string): Promise<void> => {
+  const login = async (userId: string, role: Role): Promise<void> => {
     if(!role) {
       showToast('error', '角色不存在');
       return;

client/mobile/pages_classroom.tsx

@@ -10,20 +10,29 @@ import { ClassroomProvider, useClassroomContext } from "./components/Classroom/C
 import { ToastContainer } from 'react-toastify';
 
 const RoleSelection = () => {
-  const { setRole } = useClassroomContext();
+  const { setRole, login } = useClassroomContext();
+  const { user } = useAuth();
+  const chooseRole = (role: Role) => {
+    if(!user) return;
+
+    setRole(role);
+    login(user.id.toString(), role);
+  }
   
   return (
     <div className="flex flex-col items-center justify-center h-full">
       <h2 className="text-2xl font-bold mb-8">请选择您的角色</h2>
       <div className="flex space-x-4">
         <button
-          onClick={() => setRole(Role.Teacher)}
+          type="button"
+          onClick={() => chooseRole(Role.Teacher)}
           className="px-6 py-3 bg-blue-500 text-white rounded-lg hover:bg-blue-600 transition-colors"
         >
           我是老师
         </button>
         <button
-          onClick={() => setRole(Role.Student)}
+          type="button"
+          onClick={() => chooseRole(Role.Student)}
           className="px-6 py-3 bg-green-500 text-white rounded-lg hover:bg-green-600 transition-colors"
         >
           我是学生
@@ -115,7 +124,7 @@ const Classroom = () => {
     
     if (isAuthenticated && user && !isLoggedIn && role && classId) {
       (async () => {
-        await login(user.id.toString());
+        await login(user.id.toString(), role);
         await joinClass(classId);
       })()