diff --git a/app.py b/app.py
index ffa10cf..b0c883f 100644
--- a/app.py
+++ b/app.py
@@ -409,7 +409,7 @@ def api_contest_edit(contest_id):
     is_owner = (membership and membership.role == 'owner') or user.get('role') == 'admin'
     if not is_owner:
         return jsonify({'success': False, 'message': '没有权限'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     if data.get('description') is not None:
         contest.description = data['description']
     if data.get('organizer') is not None:
@@ -692,7 +692,7 @@ def api_user_friends():
 @login_required
 def api_add_friend():
     user_id = session['user']['id']
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     friend_id = data.get('friend_id')
     if not friend_id or friend_id == user_id:
         return jsonify({'success': False, 'message': '无效的好友ID'}), 400
@@ -893,7 +893,7 @@ def api_change_name():
         if datetime.utcnow() - user.name_changed_at < timedelta(days=30):
             remaining = 30 - (datetime.utcnow() - user.name_changed_at).days
             return jsonify({'success': False, 'message': f'每月仅可修改一次用户名，还需等待{remaining}天'}), 400
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     new_name = data.get('name', '').strip()
     if not new_name or len(new_name) > 80:
         return jsonify({'success': False, 'message': '用户名不能为空且不超过80字符'}), 400
@@ -1159,7 +1159,7 @@ def api_system_notifications():
 @admin_required
 def api_create_system_notification():
     """管理员发布系统公告"""
-    data = request.get_json() or {}
+    data = request.get_json(force=True, silent=True) or {}
     title = (data.get('title') or '').strip()
     content = (data.get('content') or '').strip()
     if not title or not content:
@@ -1183,7 +1183,7 @@ def api_create_system_notification():
 def api_update_system_notification(sn_id):
     """管理员修改系统公告"""
     sn = SystemNotification.query.get_or_404(sn_id)
-    data = request.get_json() or {}
+    data = request.get_json(force=True, silent=True) or {}
     if 'title' in data:
         sn.title = data['title'].strip()
     if 'content' in data:
@@ -1221,7 +1221,7 @@ def api_admin_search_users():
 @app.route('/api/admin/send-private-notification', methods=['POST'])
 @admin_required
 def api_admin_send_private_notification():
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     user_ids = data.get('user_ids', [])
     content = data.get('content', '').strip()
     if not user_ids or not content:
@@ -1523,7 +1523,7 @@ def reject_teacher_application(app_id):
 def api_activate_invite_code():
     """老师输入邀请码激活教师身份"""
     user = session['user']
-    data = request.get_json() or {}
+    data = request.get_json(force=True, silent=True) or {}
     code_str = (data.get('code') or '').strip()
     if not code_str:
         return jsonify({'success': False, 'message': '请输入邀请码'}), 400
@@ -1585,7 +1585,7 @@ def api_captcha():
 @app.route('/api/send-email-code', methods=['POST'])
 def api_send_email_code():
     global captcha_store, email_codes
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     email = data.get('email', '')
     captcha_id = data.get('captchaId', '')
     captcha_text = data.get('captchaText', '')
@@ -1623,7 +1623,7 @@ def api_send_email_code():
 def api_register():
     """邮箱注册（需绑定手机号）"""
     global email_codes
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     name = data.get('name', '')
     email = data.get('email', '')
     phone = data.get('phone', '')
@@ -1667,7 +1667,7 @@ def api_register():
 @app.route('/api/register-mobile', methods=['POST'])
 def api_register_mobile():
     """手机号注册"""
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     name = data.get('name', '')
     phone = data.get('phone', '')
     password = data.get('password', '')
@@ -1737,7 +1737,7 @@ def api_login():
 @app.route('/api/send-sms', methods=['POST'])
 def api_send_sms():
     global captcha_store
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     phone = data.get('phone', '')
     captcha_id = data.get('captchaId', '')
     captcha_text = data.get('captchaText', '')
@@ -1795,7 +1795,7 @@ def api_send_sms():
 
 @app.route('/api/verify-code', methods=['POST'])
 def api_verify_code():
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     phone = data.get('phone', '')
     code = data.get('code', '')
 
@@ -2278,7 +2278,7 @@ def api_create_exam():
     user = session.get('user')
     if not user:
         return jsonify({'success': False, 'message': '请先登录'}), 401
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     contest_id = data.get('contest_id')
 
     # 杯赛考试：只有杯赛负责人或系统管理员可以创建
@@ -2360,7 +2360,7 @@ def api_verify_exam_password(exam_id):
     exam = Exam.query.get(exam_id)
     if not exam:
         return jsonify({'success': False, 'message': '考试不存在'}), 404
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     password = data.get('password', '')
     if password == exam.access_password:
         session[f'exam_verified_{exam_id}'] = True
@@ -2375,7 +2375,7 @@ def api_save_draft(exam_id):
     exam = Exam.query.get(exam_id)
     if not exam:
         return jsonify({'success': False, 'message': '试卷不存在'}), 404
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     answers = data.get('answers', {})
     draft = Draft.query.filter_by(exam_id=exam_id, user_id=user.get('id')).first()
     if not draft:
@@ -2403,7 +2403,7 @@ def api_submit_exam(exam_id):
         return jsonify({'success': False, 'message': '考试已结束'}), 400
     if Submission.query.filter_by(exam_id=exam_id, user_id=user.get('id')).first():
         return jsonify({'success': False, 'message': '您已提交过该试卷'}), 400
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     answers = data.get('answers', {})
     score = 0
     auto_graded = True
@@ -2455,7 +2455,7 @@ def api_grade_submission(exam_id, sub_id):
         return jsonify({'success': False, 'message': '考试不存在'}), 404
     if not can_grade_exam(user, exam):
         return jsonify({'success': False, 'message': '无权限'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     scores = data.get('scores', {})
     total = sum(scores.values())
     sub.score = total
@@ -2479,7 +2479,7 @@ def api_update_exam_status(exam_id):
         return jsonify({'success': False, 'message': '试卷不存在'}), 404
     if exam.creator_id != user.get('id'):
         return jsonify({'success': False, 'message': '只能修改自己创建的试卷'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     new_status = data.get('status', '')
     if new_status not in ('available', 'closed'):
         return jsonify({'success': False, 'message': '无效状态'}), 400
@@ -2595,7 +2595,7 @@ def api_import_exam_to_contest(contest_id):
     is_owner = (membership and membership.role == 'owner') or user.get('role') == 'admin'
     if not is_owner:
         return jsonify({'success': False, 'message': '无权操作'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     exam_id = data.get('exam_id')
     if not exam_id:
         return jsonify({'success': False, 'message': '请选择考试'}), 400
@@ -2620,7 +2620,7 @@ def api_remove_exam_from_contest(contest_id):
     is_owner = (membership and membership.role == 'owner') or user.get('role') == 'admin'
     if not is_owner:
         return jsonify({'success': False, 'message': '无权操作'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     exam_id = data.get('exam_id')
     exam = Exam.query.get(exam_id)
     if not exam or exam.contest_id != contest_id:
@@ -2689,7 +2689,7 @@ def api_create_contest():
     user = session.get('user')
     if not user:
         return jsonify({'success': False, 'message': '请先登录'}), 401
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     contest = Contest(
         name=data.get('name'),
         organizer=data.get('organizer'),
@@ -2749,7 +2749,7 @@ def api_add_question_bank(contest_id):
     membership = ContestMembership.query.filter_by(user_id=user['id'], contest_id=contest_id).first()
     if not membership and user.get('role') != 'admin':
         return jsonify({'success': False, 'message': '无权限'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     qtype = data.get('type', '')
     content = data.get('content', '')
     if not qtype or not content:
@@ -2798,7 +2798,7 @@ def api_create_exam_from_bank(contest_id):
     membership = ContestMembership.query.filter_by(user_id=user['id'], contest_id=contest_id, role='owner').first()
     if not membership and user.get('role') != 'admin':
         return jsonify({'success': False, 'message': '只有杯赛负责人才能组卷'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     title = data.get('title', '')
     duration = data.get('duration', 120)
     question_ids = data.get('question_ids', [])
@@ -2956,7 +2956,7 @@ def api_create_contest_post(contest_id):
     if not can_post_in_contest(user, contest):
         return jsonify({'success': False, 'message': '您没有权限在此杯赛讨论区发帖'}), 403
 
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     title = data.get('title', '').strip()
     content = data.get('content', '').strip()
     if not title or not content:
@@ -3033,7 +3033,7 @@ def api_create_post():
     user = session.get('user')
     if not user:
         return jsonify({'success': False, 'message': '请先登录'}), 401
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     title = data.get('title', '').strip()
     content = data.get('content', '').strip()
     tag = data.get('tag', '全部')
@@ -3175,7 +3175,7 @@ def api_create_reply(post_id):
     post = Post.query.get(post_id)
     if not post:
         return jsonify({'success': False, 'message': '帖子不存在'}), 404
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     content = data.get('content', '').strip()
     if not content:
         return jsonify({'success': False, 'message': '回复内容不能为空'}), 400
@@ -3266,7 +3266,7 @@ def api_edit_post(post_id):
         return jsonify({'success': False, 'message': '帖子不存在'}), 404
     if post.author_id != user.get('id') and user.get('role') not in ('teacher', 'admin'):
         return jsonify({'success': False, 'message': '无权编辑'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     new_title = data.get('title', '').strip()
     new_content = data.get('content', '').strip()
     new_tag = data.get('tag', post.tag)
@@ -3288,7 +3288,7 @@ def api_edit_reply(reply_id):
         return jsonify({'success': False, 'message': '回复不存在'}), 404
     if reply.author_id != user.get('id'):
         return jsonify({'success': False, 'message': '无权编辑'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     new_content = data.get('content', '').strip()
     if not new_content:
         return jsonify({'success': False, 'message': '内容不能为空'}), 400
@@ -3308,7 +3308,7 @@ def api_create_poll(post_id):
         return jsonify({'success': False, 'message': '只有作者可以创建投票'}), 403
     if post.poll:
         return jsonify({'success': False, 'message': '该帖子已有投票'}), 400
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     question = data.get('question', '').strip()
     options = data.get('options', [])
     multi = data.get('multi', False)
@@ -3338,7 +3338,7 @@ def api_vote_poll(post_id):
     voters = poll.get_voters()
     if str(uid) in voters:
         return jsonify({'success': False, 'message': '您已投过票'}), 400
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     choices = data.get('choices', [])
     if not choices:
         return jsonify({'success': False, 'message': '请选择选项'}), 400
@@ -3388,7 +3388,7 @@ def api_report():
     user = session.get('user')
     if not user:
         return jsonify({'success': False, 'message': '请先登录'}), 401
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     rtype = data.get('type', '')
     target_id = data.get('target_id', 0)
     reason = data.get('reason', '')
@@ -3414,7 +3414,7 @@ def api_react_post(post_id):
     post = Post.query.get(post_id)
     if not post:
         return jsonify({'success': False, 'message': '帖子不存在'}), 404
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     reaction_type = data.get('reaction', '')
     if reaction_type not in ('like', 'love', 'haha', 'wow', 'sad', 'angry'):
         return jsonify({'success': False, 'message': '无效反应'}), 400
@@ -3548,7 +3548,7 @@ def api_create_post_with_poll():
     user = session.get('user')
     if not user:
         return jsonify({'success': False, 'message': '请先登录'}), 401
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     title = data.get('title', '').strip()
     content = data.get('content', '').strip()
     tag = data.get('tag', '全部')
@@ -3640,7 +3640,7 @@ def api_chat_rooms():
 def api_create_chat_room():
     """创建群聊"""
     user_id = session['user']['id']
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     name = data.get('name', '').strip()
     member_ids = data.get('member_ids', [])
     if not name:
@@ -3668,7 +3668,7 @@ def api_update_chat_room(room_id):
     member = ChatRoomMember.query.filter_by(room_id=room_id, user_id=user_id).first()
     if not member or member.role != 'admin':
         return jsonify({'success': False, 'message': '无权限'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     if 'name' in data:
         room.name = data['name']
     if 'avatar' in data:
@@ -3780,7 +3780,7 @@ def api_invite_chat_members(room_id):
     member = ChatRoomMember.query.filter_by(room_id=room_id, user_id=user_id).first()
     if not member:
         return jsonify({'success': False, 'message': '您不是该聊天室成员'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     user_ids = data.get('user_ids', [])
     added = []
     for uid in user_ids:
@@ -3977,7 +3977,7 @@ def api_set_announcement(room_id):
     if not member or member.role != 'admin':
         return jsonify({'success': False, 'message': '无权限'}), 403
     room = ChatRoom.query.get_or_404(room_id)
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     room.announcement = data.get('content', '').strip()
     room.announcement_by = user_id
     room.announcement_at = datetime.utcnow()
@@ -4106,7 +4106,7 @@ def api_set_nickname(room_id):
     member = ChatRoomMember.query.filter_by(room_id=room_id, user_id=user_id).first()
     if not member:
         return jsonify({'success': False, 'message': '您不是该聊天室成员'}), 403
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     member.nickname = data.get('nickname', '').strip()[:50]
     db.session.commit()
     return jsonify({'success': True})
@@ -4116,7 +4116,7 @@ def api_set_nickname(room_id):
 def api_toggle_reaction(msg_id):
     """添加/取消表情回应"""
     user_id = session['user']['id']
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     emoji = data.get('emoji', '')
     if not emoji:
         return jsonify({'success': False, 'message': '请选择表情'}), 400
@@ -4229,7 +4229,7 @@ def admin_contests_api():
         } for c in contests]
         return jsonify({'success': True, 'contests': data})
     elif request.method == 'POST':
-        data = request.get_json()
+        data = request.get_json(force=True, silent=True)
         contest = Contest(
             name=data['name'],
             organizer=data['organizer'],
@@ -4259,7 +4259,7 @@ def admin_contest_detail(contest_id):
             'status': contest.status
         }})
     elif request.method == 'PUT':
-        data = request.get_json()
+        data = request.get_json(force=True, silent=True)
         contest.name = data.get('name', contest.name)
         contest.organizer = data.get('organizer', contest.organizer)
         contest.start_date = data.get('start_date', contest.start_date)
@@ -4384,7 +4384,7 @@ def admin_update_exam_status(exam_id):
     exam = Exam.query.get(exam_id)
     if not exam:
         return jsonify({'success': False, 'message': '考试不存在'})
-    data = request.get_json()
+    data = request.get_json(force=True, silent=True)
     exam.status = data.get('status', exam.status)
     db.session.commit()
     return jsonify({'success': True})