diff --git a/CardSharp/GameSteps/CommandParser.cs b/CardSharp/GameSteps/CommandParser.cs
index f93461a..84b4b48 100644
--- a/CardSharp/GameSteps/CommandParser.cs
+++ b/CardSharp/GameSteps/CommandParser.cs
@@ -100,6 +100,7 @@ private void ParsePlayerSubmitCard(Desk desk, Player player, string command)
             if (command.StartsWith("出"))
             {
                 desk.AddMessage("出的命令已经被替换为直接出牌. 如<出34567>被替换为<34567>");
+                command = command.Substring(1);
             }
             var cardsCommand = command.ToUpper();
             if (cardsCommand.IsValidCardString())
diff --git a/CardSharp/MessageSenderBase.cs b/CardSharp/MessageSenderBase.cs
index 8e3c562..632e245 100644
--- a/CardSharp/MessageSenderBase.cs
+++ b/CardSharp/MessageSenderBase.cs
@@ -1,33 +1,45 @@
 using System;
 using System.Runtime.CompilerServices;
+using System.Threading;
 
 namespace CardSharp
 {
     public abstract class MessageSenderBase : IMessageSender
     {
-        private readonly object _locker = new object();
-        public string Message { get; private set; }
+        private volatile string _message;
+        private readonly ReaderWriterLockSlim _rwlock = new ReaderWriterLockSlim();
 
-        public virtual void AddMessage(string msg)
+        public string Message
         {
-            lock (_locker)
+            get
+            {
+                _rwlock.EnterReadLock();
+                var str = _message;
+                _rwlock.ExitReadLock();
+                return str;
+            }
+            set
             {
-                Message += msg;
+                _rwlock.EnterWriteLock();
+                _message = value;
+                _rwlock.ExitWriteLock();
             }
         }
 
+        public virtual void AddMessage(string msg)
+        {
+            Message += msg;
+        }
+
         public void ClearMessage()
         {
-            lock (_locker)
-            {
-                Message = null;
-            }
+            Message = null;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void AddMessageLine(string msg = "")
         {
-            if (!Message?.EndsWith(Environment.NewLine) == true)
+            if (Message?.EndsWith(Environment.NewLine) != true)
             {
                 AddMessage(Environment.NewLine);
             }
diff --git a/CardSharp/StringExtensions.cs b/CardSharp/StringExtensions.cs
index 2b2c23d..e9be497 100644
--- a/CardSharp/StringExtensions.cs
+++ b/CardSharp/StringExtensions.cs
@@ -14,7 +14,7 @@ public static string AddNewLine(this string source)
 
         public static bool IsValidCardString(this string source)
         {
-            return Regex.IsMatch(source, "([2-9]|10|A|王|鬼|J|Q|K).*");
+            return Regex.IsMatch(source, "^([2-9]|10|A|王|鬼|J|Q|K).*$");
         }
 
         public static IEnumerable<Card> ToCards(this string source)
@@ -23,18 +23,21 @@ public static IEnumerable<Card> ToCards(this string source)
             for (var index = 0; index < source.Length; index++)
             {
                 var chara = source[index];
-                if (int.TryParse(chara.ToString(), out var num))
+                if (chara >= '0' && chara <= '9')
+                {
+                    var num = chara - '0';
                     if (num >= 3 && num <= 9)
                     {
                         yield return new Card(num - px);
                         continue;
                     }
-                    else if (num == 1)
+                    if (num == 1)
                     {
                         index++;
                         yield return new Card(Constants.Cards.C10);
                         continue;
                     }
+                }
 
                 switch (chara)
                 {