fixed missing TextTheme

Author: sunhuachuang

lib/apps/file/list.dart

@@ -94,7 +94,7 @@ class _FilesListState extends State<FilesList> {
             const SizedBox(height: 20.0),
             Align(
               alignment: Alignment.centerLeft,
-              child: Text('Recents', style: Theme.of(context).textTheme.title)
+              child: Text('Recents', style: Theme.of(context).textTheme.caption)
             ),
             Expanded(
               child: GridView.extent(

lib/apps/group_chat/add.dart

@@ -323,7 +323,7 @@ class _GroupAddPageState extends State<GroupAddPage> {
                         padding: const EdgeInsets.all(10.0),
                         alignment: Alignment.centerLeft,
                         child: Text('1. ' + lang.groupChatAddr, textAlign: TextAlign.left,
-                          style: Theme.of(context).textTheme.title),
+                          style: Theme.of(context).textTheme.headline6),
                       ),
                       Container(
                         padding: EdgeInsets.only(bottom: 10.0),
@@ -410,7 +410,7 @@ class _GroupAddPageState extends State<GroupAddPage> {
                         padding: const EdgeInsets.all(10.0),
                         alignment: Alignment.centerLeft,
                         child: Text('2. ' + lang.groupChatInfo, textAlign: TextAlign.left,
-                          style: Theme.of(context).textTheme.title),
+                          style: Theme.of(context).textTheme.headline6),
                       ),
                       Container(
                         width: 100.0,

lib/apps/group_chat/detail.dart

@@ -646,7 +646,7 @@ class _MemberWidget extends StatelessWidget {
         Container(
           alignment: Alignment.centerRight,
           child: Text("${lang.members} (${allKeys.length + 1})",
-            style: Theme.of(context).textTheme.title),
+            style: Theme.of(context).textTheme.headline6),
         ),
         const SizedBox(height: 10.0),
         const Divider(height: 1.0, color: Color(0x40ADB0BB)),