diff --git a/src/DownKyi.Core/Storage/Database/DbHelper.cs b/src/DownKyi.Core/Storage/Database/DbHelper.cs
index 56b4c57..a2e753f 100644
--- a/src/DownKyi.Core/Storage/Database/DbHelper.cs
+++ b/src/DownKyi.Core/Storage/Database/DbHelper.cs
@@ -72,6 +72,8 @@ namespace DownKyi.Core.Storage.Database
         /// </summary>
         public void Open()
         {
+            if (conn == null) { return; }
+
             if (!IsOpen())
             {
                 conn.Open();
@@ -83,6 +85,8 @@ namespace DownKyi.Core.Storage.Database
         /// </summary>
         public void Close()
         {
+            if (conn == null) { return; }
+
             if (IsOpen())
             {
                 conn.Close();
@@ -97,6 +101,8 @@ namespace DownKyi.Core.Storage.Database
         /// <param name="sql"></param>
         public void ExecuteNonQuery(string sql, Action<SQLiteParameterCollection> action = null)
         {
+            if (conn == null) { return; }
+
             try
             {
                 lock (conn)
@@ -129,6 +135,8 @@ namespace DownKyi.Core.Storage.Database
         /// <param name="action"></param>
         public void ExecuteQuery(string sql, Action<SQLiteDataReader> action)
         {
+            if (conn == null) { return; }
+
             try
             {
                 lock (conn)
diff --git a/src/DownKyi.Core/Storage/StorageCover.cs b/src/DownKyi.Core/Storage/StorageCover.cs
index eb0a115..13aa340 100644
--- a/src/DownKyi.Core/Storage/StorageCover.cs
+++ b/src/DownKyi.Core/Storage/StorageCover.cs
@@ -44,10 +44,30 @@ namespace DownKyi.Core.Storage
         {
             if (cover == null) { return null; }
 
-            Bitmap bitmap = new Bitmap(cover);
-            Image thumbnail = bitmap.GetThumbnailImage(width, height, null, IntPtr.Zero);
+            try
+            {
+                Bitmap bitmap = new Bitmap(cover);
+                Image thumbnail = bitmap.GetThumbnailImage(width, height, null, IntPtr.Zero);
+
+                return StorageUtils.BitmapToBitmapImage(new Bitmap(thumbnail));
+            }
+            catch (ArgumentException e)
+            {
+                Utils.Debugging.Console.PrintLine(cover);
+                Utils.Debugging.Console.PrintLine("GetCoverThumbnail()发生异常: {0}", e);
+
+                LogManager.Error("StorageCover.GetCoverThumbnail()", cover);
+                LogManager.Error("StorageCover.GetCoverThumbnail()", e);
 
-            return StorageUtils.BitmapToBitmapImage(new Bitmap(thumbnail));
+                return null;
+            }
+            catch (Exception e)
+            {
+                Utils.Debugging.Console.PrintLine("GetCoverThumbnail()发生异常: {0}", e);
+                LogManager.Error("StorageCover.GetCoverThumbnail()", e);
+
+                return null;
+            }
         }
 
         /// <summary>
diff --git a/src/DownKyi.Core/Storage/StorageHeader.cs b/src/DownKyi.Core/Storage/StorageHeader.cs
index a0d3077..5a89e99 100644
--- a/src/DownKyi.Core/Storage/StorageHeader.cs
+++ b/src/DownKyi.Core/Storage/StorageHeader.cs
@@ -44,10 +44,30 @@ namespace DownKyi.Core.Storage
         {
             if (header == null) { return null; }
 
-            var bitmap = new Bitmap(header);
-            var thumbnail = bitmap.GetThumbnailImage(width, height, null, IntPtr.Zero);
+            try
+            {
+                Bitmap bitmap = new Bitmap(header);
+                Image thumbnail = bitmap.GetThumbnailImage(width, height, null, IntPtr.Zero);
+
+                return StorageUtils.BitmapToBitmapImage(new Bitmap(thumbnail));
+            }
+            catch (ArgumentException e)
+            {
+                Utils.Debugging.Console.PrintLine(header);
+                Utils.Debugging.Console.PrintLine("GetHeaderThumbnail()发生异常: {0}", e);
+
+                LogManager.Error("StorageHeader.GetHeaderThumbnail()", header);
+                LogManager.Error("StorageHeader.GetHeaderThumbnail()", e);
 
-            return StorageUtils.BitmapToBitmapImage(new Bitmap(thumbnail));
+                return null;
+            }
+            catch (Exception e)
+            {
+                Utils.Debugging.Console.PrintLine("GetHeaderThumbnail()发生异常: {0}", e);
+                LogManager.Error("StorageHeader.GetHeaderThumbnail()", e);
+
+                return null;
+            }
         }
 
         /// <summary>
@@ -58,7 +78,7 @@ namespace DownKyi.Core.Storage
         public string GetHeader(long mid, string name, string url)
         {
             HeaderDb headerDb = new HeaderDb();
-            var header = headerDb.QueryByMid(mid);
+            Header header = headerDb.QueryByMid(mid);
 
             if (header != null)
             {