diff --git a/src/c#/GeneralUpdate.Core/ContentProvider/FileProvider-Filter.cs b/src/c#/GeneralUpdate.Core/ContentProvider/FileProvider-Filter.cs
index e399f574..6fe01323 100644
--- a/src/c#/GeneralUpdate.Core/ContentProvider/FileProvider-Filter.cs
+++ b/src/c#/GeneralUpdate.Core/ContentProvider/FileProvider-Filter.cs
@@ -4,7 +4,18 @@ namespace GeneralUpdate.Core.ContentProvider
 {
     public partial class FileProvider
     {
-        private static List<string> _blackFiles, _blackFileFormats;
+        private static List<string> _blackFiles,
+            _blackFileFormats;
+        private static readonly List<string> DefaultBlackFileFormats = new List<string>(6)
+        {
+            ".patch",
+            ".7z",
+            ".zip",
+            ".rar",
+            ".tar",
+            ".json"
+        };
+        private static readonly List<string> DefaultBlackFiles = new List<string>(1) { "Newtonsoft.Json.dll" };
 
         /// <summary>
         /// Set a blacklist.
@@ -21,12 +32,14 @@ public static void SetBlacklist(List<string> blackFiles, List<string> blackFileF
         /// These files will be skipped when updating.
         /// </summary>
         /// <returns></returns>
-        public static List<string> GetBlackFiles() => _blackFiles ?? new List<string>() { "Newtonsoft.Json.dll" };
+        public static List<string> GetBlackFiles() =>
+            _blackFiles ?? DefaultBlackFiles;
 
         /// <summary>
         /// These files that contain the file suffix will be skipped when updating.
         /// </summary>
         /// <returns></returns>
-        public static List<string> GetBlackFileFormats() => _blackFileFormats ?? new List<string>() { ".patch", ".7z", ".zip", ".rar", ".tar", ".json" };
+        public static List<string> GetBlackFileFormats() =>
+            _blackFileFormats ?? DefaultBlackFileFormats;
     }
-}
\ No newline at end of file
+}
diff --git a/src/c#/GeneralUpdate.Core/ContentProvider/FileProvider-Serialization.cs b/src/c#/GeneralUpdate.Core/ContentProvider/FileProvider-Serialization.cs
index ebf0a6de..9dd15143 100644
--- a/src/c#/GeneralUpdate.Core/ContentProvider/FileProvider-Serialization.cs
+++ b/src/c#/GeneralUpdate.Core/ContentProvider/FileProvider-Serialization.cs
@@ -9,8 +9,13 @@ public partial class FileProvider
     {
         public static void CreateJson<T>(string targetPath, T obj)
         {
-            if (!Directory.Exists(targetPath)) Directory.CreateDirectory(targetPath);
-            if (File.Exists(targetPath)) File.Delete(targetPath);
+            var folderPath = Path.GetDirectoryName(targetPath) ??
+                             throw new ArgumentException("invalid path", nameof(targetPath));
+            if (!Directory.Exists(folderPath))
+            {
+                Directory.CreateDirectory(folderPath);
+            }
+            
             var jsonString = JsonConvert.SerializeObject(obj);
             File.WriteAllText(targetPath, jsonString);
         }
@@ -20,10 +25,7 @@ public static T GetJson<T>(string path)
             if (File.Exists(path))
             {
                 var json = File.ReadAllText(path);
-                if (json != null)
-                {
-                    return JsonConvert.DeserializeObject<T>(json);
-                }
+                return JsonConvert.DeserializeObject<T>(json);
             }
             return default(T);
         }
diff --git a/src/c#/GeneralUpdate.Core/HashAlgorithms/HashAlgorithmBase.cs b/src/c#/GeneralUpdate.Core/HashAlgorithms/HashAlgorithmBase.cs
index 09ed6b71..c9db372c 100644
--- a/src/c#/GeneralUpdate.Core/HashAlgorithms/HashAlgorithmBase.cs
+++ b/src/c#/GeneralUpdate.Core/HashAlgorithms/HashAlgorithmBase.cs
@@ -16,7 +16,7 @@ public string ComputeHash(string fileName)
             {
                 using (var file = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read))
                 {
-                    var dataArray = GetHashAlgorithm().ComputeHash(file);
+                    var dataArray = hashAlgorithm.ComputeHash(file);
                     var stringBuilder = new StringBuilder();
                     for (int i = 0; i < dataArray.Length; i++)
                     {
diff --git a/src/c#/GeneralUpdate.Differential/DifferentialCore.cs b/src/c#/GeneralUpdate.Differential/DifferentialCore.cs
index 38586f63..9fd835d3 100644
--- a/src/c#/GeneralUpdate.Differential/DifferentialCore.cs
+++ b/src/c#/GeneralUpdate.Differential/DifferentialCore.cs
@@ -68,12 +68,15 @@ public async Task Clean(string sourcePath, string targetPath, string patchPath =
         {
             try
             {
-                if (string.IsNullOrWhiteSpace(patchPath)) patchPath = Path.Combine(Environment.CurrentDirectory, PATCHS);
-                if (!Directory.Exists(patchPath)) Directory.CreateDirectory(patchPath);
+                if (string.IsNullOrWhiteSpace(patchPath)) 
+                    patchPath = Path.Combine(Environment.CurrentDirectory, PATCHS);
+                if (!Directory.Exists(patchPath))
+                    Directory.CreateDirectory(patchPath);
 
                 //Take the left tree as the center to match the files that are not in the right tree .
                 var fileProvider = new FileProvider();
                 var nodes = await fileProvider.Compare(sourcePath, targetPath);
+                var hashAlgorithm = new Sha256HashAlgorithm();
 
                 //Binary differencing of like terms .
                 foreach (var file in nodes.Item3)
@@ -93,25 +96,35 @@ public async Task Clean(string sourcePath, string targetPath, string patchPath =
                         if (!Directory.Exists(tempDir)) Directory.CreateDirectory(tempDir);
                         tempPath0 = Path.Combine(tempDir, $"{file.Name}{PATCH_FORMAT}");
                     }
+                    
                     var finOldFile = nodes.Item1.FirstOrDefault(i => i.Name.Equals(file.Name));
-                    var oldfile = finOldFile == null ? "" : finOldFile.FullName;
-                    var newfile = file.FullName;
+                    var oldFile = finOldFile == null ? "" : finOldFile.FullName;
+                    var newFile = file.FullName;
                     var extensionName = Path.GetExtension(file.FullName);
-                    if (File.Exists(oldfile) && File.Exists(newfile) && !FileProvider.GetBlackFileFormats().Contains(extensionName))
+                    if (File.Exists(oldFile) && File.Exists(newFile) && !FileProvider.GetBlackFileFormats().Contains(extensionName))
                     {
+                        if (hashAlgorithm.ComputeHash(oldFile)
+                            .Equals(hashAlgorithm.ComputeHash(newFile), StringComparison.OrdinalIgnoreCase))
+                        {
+                            continue;
+                        }
+
                         //Generate the difference file to the difference directory .
-                        await new BinaryHandle().Clean(oldfile, newfile, tempPath0);
+                        await new BinaryHandle().Clean(oldFile, newFile, tempPath0);
                     }
                     else
                     {
-                        File.Copy(newfile, Path.Combine(tempDir, Path.GetFileName(newfile)), true);
+                        File.Copy(newFile, Path.Combine(tempDir, Path.GetFileName(newFile)), true);
                     }
                 }
 
                 //If a file is found that needs to be deleted, a list of files is written to the update package.
-                var exceptFiles = await fileProvider.Except(sourcePath, targetPath);
-                if (exceptFiles != null && exceptFiles.Count() > 0)
-                    FileProvider.CreateJson(Path.Combine(patchPath, DELETE_FILES_NAME), exceptFiles);
+                var exceptFiles = (await fileProvider.Except(sourcePath, targetPath)).ToList();
+                if (exceptFiles.Count != 0)
+                {
+                    var path = Path.Combine(patchPath, DELETE_FILES_NAME);
+                    FileProvider.CreateJson(path, exceptFiles);
+                }
             }
             catch (Exception ex)
             {
@@ -142,9 +155,16 @@ public async Task Dirty(string appPath, string patchPath)
                     var hashAlgorithm = new Sha256HashAlgorithm();
                     foreach (var file in deleteFiles)
                     {
-                        var resultFile = oldFiles.FirstOrDefault(i => string.Equals(hashAlgorithm.ComputeHash(i.FullName), file.Hash, StringComparison.OrdinalIgnoreCase));
-                        if (resultFile == null) continue;
-                        if (File.Exists(resultFile.FullName)) File.Delete(resultFile.FullName);
+                        var resultFile = oldFiles.FirstOrDefault(i => 
+                            string.Equals(hashAlgorithm.ComputeHash(i.FullName), file.Hash, StringComparison.OrdinalIgnoreCase));
+                        if (resultFile == null)
+                        {
+                            continue;
+                        }
+                        if (File.Exists(resultFile.FullName))
+                        {
+                            File.Delete(resultFile.FullName);
+                        }
                     }
                 }