1.广角/主摄切换按钮已上移：

2.新增 isSwitchingLens 状态、避免切换镜头    stop 按钮禁用，不会触发 stopRecording
倍距按钮禁用，避免连续切换
ViewModel 层也兜底：isSwitchingLens=true 时直接拒绝 stop
3.合并失败兜底提示

lib/features/recording/model/model_recording_session.dart

@@ -7,6 +7,7 @@ class RecordingSessionState {
     this.isTouchLocked = true,
     this.isPreviewReady = false,
     this.isStartingRecording = false,
+    this.isSwitchingLens = false,
     this.hasDndAccess = false,
     this.isBatteryOptimizedIgnored = true,
     this.notificationsGranted = true,
@@ -19,12 +20,14 @@ class RecordingSessionState {
     this.errorMessage,
     this.permissionWarning,
     this.fileSaveFailed = false,
+    this.segmentOutputPaths = const [],
   });
 
   final RecordingStatus status;
   final bool isTouchLocked;
   final bool isPreviewReady;
   final bool isStartingRecording;
+  final bool isSwitchingLens;
   final bool hasDndAccess;
   final bool isBatteryOptimizedIgnored;
   final bool notificationsGranted;
@@ -37,6 +40,7 @@ class RecordingSessionState {
   final String? errorMessage;
   final String? permissionWarning;
   final bool fileSaveFailed;
+  final List<String> segmentOutputPaths;
 
   bool get isRecording => status.isRecording;
 
@@ -53,6 +57,7 @@ class RecordingSessionState {
     bool? isTouchLocked,
     bool? isPreviewReady,
     bool? isStartingRecording,
+    bool? isSwitchingLens,
     bool? hasDndAccess,
     bool? isBatteryOptimizedIgnored,
     bool? notificationsGranted,
@@ -65,6 +70,7 @@ class RecordingSessionState {
     String? errorMessage,
     String? permissionWarning,
     bool? fileSaveFailed,
+    List<String>? segmentOutputPaths,
     bool clearPermissionWarning = false,
     bool clearLastSaved = false,
   }) {
@@ -73,6 +79,7 @@ class RecordingSessionState {
       isTouchLocked: isTouchLocked ?? this.isTouchLocked,
       isPreviewReady: isPreviewReady ?? this.isPreviewReady,
       isStartingRecording: isStartingRecording ?? this.isStartingRecording,
+      isSwitchingLens: isSwitchingLens ?? this.isSwitchingLens,
       hasDndAccess: hasDndAccess ?? this.hasDndAccess,
       isBatteryOptimizedIgnored:
           isBatteryOptimizedIgnored ?? this.isBatteryOptimizedIgnored,
@@ -90,6 +97,7 @@ class RecordingSessionState {
           ? null
           : (permissionWarning ?? this.permissionWarning),
       fileSaveFailed: fileSaveFailed ?? this.fileSaveFailed,
+      segmentOutputPaths: segmentOutputPaths ?? this.segmentOutputPaths,
     );
   }
 }

lib/features/recording/pages/page_record.dart

@@ -173,7 +173,11 @@ class _RecordingPageState extends ConsumerState<RecordingPage> {
     if (!mounted) return;
     final latest = ref.read(recordingViewModelProvider).session;
     if (latest.fileSaveFailed) {
-      AppToast.show(latest.errorMessage ?? '保存到文件夹失败，请检查文件保存权限');
+      if (latest.segmentOutputPaths.isNotEmpty) {
+        AppToast.show('视频合并失败，已为你保存分段文件，可在相册中查看');
+      } else {
+        AppToast.show(latest.errorMessage ?? '保存到文件夹失败，请检查文件保存权限');
+      }
       return;
     }
     await _showRecordingSavedDialogIfNeeded();
@@ -374,6 +378,7 @@ class _RecordingHudLayer extends ConsumerWidget {
           m.session.notificationsGranted,
           m.session.isRecording,
           m.session.isStartingRecording,
+          m.session.isSwitchingLens,
           m.session.isTouchLocked,
           m.session.zoomRatio,
           m.session.minZoomRatio,
@@ -391,6 +396,7 @@ class _RecordingHudLayer extends ConsumerWidget {
       notificationsGranted,
       isRecording,
       isStartingRecording,
+      isSwitchingLens,
       isTouchLocked,
       zoomRatio,
       minZoomRatio,
@@ -408,6 +414,7 @@ class _RecordingHudLayer extends ConsumerWidget {
       notificationsGranted: notificationsGranted,
       isRecording: isRecording,
       isStartingRecording: isStartingRecording,
+      isSwitchingLens: isSwitchingLens,
       isTouchLocked: isTouchLocked,
       zoomRatio: zoomRatio,
       minZoomRatio: minZoomRatio,

lib/features/recording/view-model/view_model_recording.dart

@@ -349,10 +349,14 @@ class RecordingViewModel extends Notifier<RecordingModel> {
   /// 设置相机倍距，原生层会返回设备实际应用后的倍距范围与当前值。
   Future<void> setZoomRatio(double ratio) async {
     final session = state.session;
+    if (session.isSwitchingLens) {
+      return;
+    }
     final clamped = ratio
         .clamp(session.minZoomRatio, session.maxZoomRatio)
         .toDouble();
 
+    _updateSession((s) => s.copyWith(isSwitchingLens: true));
     try {
       final zoom = await RecordingPlatform.setZoomRatio(clamped);
       _updateSession(
@@ -368,13 +372,19 @@ class RecordingViewModel extends Notifier<RecordingModel> {
           ? '切换镜头失败，请重试'
           : (error.message ?? '相机倍距设置失败');
       _updateSession((s) => s.copyWith(errorMessage: message));
+    } finally {
+      _updateSession(
+        (s) => s.copyWith(isSwitchingLens: false, errorMessage: s.errorMessage),
+      );
     }
   }
 
   /// 开始录制，可选开启勿扰模式。
   Future<void> startRecording({bool enableDoNotDisturb = true}) async {
     final session = state.session;
-    if (session.isRecording || session.isStartingRecording) {
+    if (session.isRecording ||
+        session.isStartingRecording ||
+        session.isSwitchingLens) {
       return;
     }
     if (!session.isPreviewReady) {
@@ -401,6 +411,7 @@ class RecordingViewModel extends Notifier<RecordingModel> {
           isTouchLocked: true,
           errorMessage: null,
           fileSaveFailed: false,
+          segmentOutputPaths: const [],
           clearLastSaved: true,
         ),
       );
@@ -415,7 +426,7 @@ class RecordingViewModel extends Notifier<RecordingModel> {
 
   /// 停止录制、保存到文件夹，并恢复相机预览。
   Future<void> stopRecording() async {
-    if (!state.session.isRecording) return;
+    if (!state.session.isRecording || state.session.isSwitchingLens) return;
 
     try {
       final result = await RecordingPlatform.stopRecording();
@@ -432,6 +443,7 @@ class RecordingViewModel extends Notifier<RecordingModel> {
               ? (result.fileErrorMessage ?? '保存到文件夹失败，请检查文件保存权限')
               : null,
           fileSaveFailed: fileFailed,
+          segmentOutputPaths: result.segmentOutputPaths,
         ),
       );
     } on PlatformException catch (error) {

lib/features/recording/widgets/widget_recording_hud.dart

@@ -18,6 +18,7 @@ class RecordingHudWidget extends StatelessWidget {
     required this.notificationsGranted,
     required this.isRecording,
     required this.isStartingRecording,
+    required this.isSwitchingLens,
     required this.isTouchLocked,
     this.showClipboardHint = false,
     this.clipboardAddress = '',
@@ -39,6 +40,7 @@ class RecordingHudWidget extends StatelessWidget {
   final bool notificationsGranted;
   final bool isRecording;
   final bool isStartingRecording;
+  final bool isSwitchingLens;
   final bool isTouchLocked;
   final bool showClipboardHint;
   final String clipboardAddress;
@@ -143,8 +145,9 @@ class RecordingHudWidget extends StatelessWidget {
           ),
         Positioned(
           right: 16.r,
-          bottom: _recordButtonBottom + _recordButtonSize + 14.h,
+          bottom: 260.r,
           child: _ZoomPresetControl(
+            enabled: !isSwitchingLens,
             zoomRatio: zoomRatio,
             minZoomRatio: minZoomRatio,
             maxZoomRatio: maxZoomRatio,
@@ -160,7 +163,7 @@ class RecordingHudWidget extends StatelessWidget {
             child: RecordingControlButton(
               isRecording: isRecording,
               isStartingRecording: isStartingRecording,
-              enabled: !isStartingRecording,
+              enabled: !isStartingRecording && !isSwitchingLens,
               size: _recordButtonSize,
               onTap: () {
                 if (isRecording) {
@@ -197,6 +200,7 @@ class RecordingHudWidget extends StatelessWidget {
 
 class _ZoomPresetControl extends StatelessWidget {
   const _ZoomPresetControl({
+    required this.enabled,
     required this.zoomRatio,
     required this.minZoomRatio,
     required this.maxZoomRatio,
@@ -204,6 +208,7 @@ class _ZoomPresetControl extends StatelessWidget {
     required this.onSelected,
   });
 
+  final bool enabled;
   final double zoomRatio;
   final double minZoomRatio;
   final double maxZoomRatio;
@@ -235,7 +240,7 @@ class _ZoomPresetControl extends StatelessWidget {
                 displayRatio: preset,
                 requestRatio: preset,
                 selected: _isPresetSelected(preset),
-                enabled: true,
+                enabled: enabled,
                 onSelected: onSelected,
               ),
           ],