fix: 🐛 Fix the client's bug when playback file is null.

Author: DreamEnderKing

Diff for: logic/Client/ViewModel/GeneralViewModel.cs

@@ -1079,7 +1079,7 @@ Show the error message
             myLogger.LogInfo(String.Format("ip:{0}, port:{1}, playerid:{2}, teamid:{3}, shiptype:{4}, playbackfile:{5}, playbackspeed:{6}", ip, port, playerID, teamID, shipTypeID, playbackFile, playbackSpeed));
 
             //Playback("E:\\program\\Project\\playback.thuaipb", 0.5);
-            if (playbackFile.Length == 0)
+            if (string.IsNullOrEmpty(playbackFile))
             {
                 try
                 {
@@ -1099,14 +1099,15 @@ Show the error message
                     ConnectToServer(comInfo);
                     OnReceive();
                 }
-                catch
+                catch (Exception e)
                 {
+                    myLogger.LogError(e.Message);
                     OnReceive();
                 }
             }
             else
             {
-                //myLogger.LogInfo(String.Format("PlaybackFile:{0}", playbackFile));
+                myLogger.LogInfo(String.Format("PlaybackFile:{0}", playbackFile));
                 Playback(playbackFile, playbackSpeed);
             }
             //连接Server,comInfo[] 的格式：0 - ip 1 - port 2 - playerID 3 - teamID 4 - ShipType