use querymembers

lib/src/message_input.dart

@@ -392,6 +392,16 @@ class MessageInputState extends State<MessageInput> {
         .split('@');
     final query = splits.last.toLowerCase();
 
+    Future<List<Member>> queryMembers;
+
+    if (query.isNotEmpty) {
+      queryMembers = StreamChannel.of(context).channel.queryMembers(filter: {
+        'name': {
+          '\$autocomplete': query,
+        },
+      }).then((res) => res.members);
+    }
+
     final members = StreamChannel.of(context).channel.state.members?.where((m) {
           return m.user.name.toLowerCase().contains(query);
         })?.toList() ??
@@ -419,10 +429,14 @@ class MessageInputState extends State<MessageInput> {
               ],
               color: StreamChatTheme.of(context).primaryColor,
             ),
-            child: ListView(
+            child: FutureBuilder<List<Member>>(
+                future: queryMembers ?? Future.value(members),
+                initialData: members,
+                builder: (context, snapshot) {
+                  return ListView(
                     padding: const EdgeInsets.all(0),
                     shrinkWrap: true,
-              children: members
+                    children: snapshot.data
                         .map((m) => ListTile(
                               leading: UserAvatar(
                                 user: m.user,
@@ -437,7 +451,8 @@ class MessageInputState extends State<MessageInput> {
                                 textEditingController.value = TextEditingValue(
                                   text: rejoin +
                                       textEditingController.text.substring(
-                                    textEditingController.selection.start),
+                                          textEditingController
+                                              .selection.start),
                                   selection: TextSelection.collapsed(
                                     offset: rejoin.length,
                                   ),
@@ -448,7 +463,8 @@ class MessageInputState extends State<MessageInput> {
                               },
                             ))
                         .toList(),
-            ),
+                  );
+                }),
           ),
         ),
       );