add protections in database reading

Assets/YGOSharp/CardsManager.cs

@@ -16,7 +16,7 @@ namespace YGOSharp
 
         public static string nullString = "";
 
-        internal static void initialize(string databaseFullPath)
+        internal static bool initialize(string databaseFullPath)
         {
             nullName = InterString.Get("未知卡片");
             nullString = "";
@@ -27,6 +27,8 @@ namespace YGOSharp
             nullString += "更多关于电脑/安卓版KoishiPro及7210服务器的信息可加QQ群338443272";
             nullString += "\r\n\r\n";
             nullString += "喜欢游戏王DIY的朋友欢迎来222服QQ群642043095";
+            bool success = true;
+            try {
                 using (SqliteConnection connection = new SqliteConnection("Data Source=" + databaseFullPath))
                 {
                     connection.Open();
@@ -43,6 +45,11 @@ namespace YGOSharp
                     }
                 }
             }
+            catch (System.Exception e) {
+                success = false;
+            }
+            return success;
+        }
 
         internal static Card GetCard(int id)
         {