diff --git a/binding/csharp/IP2Region.Net/Internal/ContentCacheStrategy.cs b/binding/csharp/IP2Region.Net/Internal/ContentCacheStrategy.cs
index 020a959..2e980b7 100644
--- a/binding/csharp/IP2Region.Net/Internal/ContentCacheStrategy.cs
+++ b/binding/csharp/IP2Region.Net/Internal/ContentCacheStrategy.cs
@@ -3,25 +3,32 @@
 // license that can be found in the LICENSE file.
 // @Author Alan <lzh.shap@gmail.com>
 // @Date   2023/07/25
-// Updated by Argo Zhang <argo@live.ca> at 2025/11/21
+// Updated by Wong <vcd.hai@outlook.com> at 2025/12/31
 
 namespace IP2Region.Net.Internal;
 
-class ContentCacheStrategy : FileCacheStrategy
+class ContentCacheStrategy(string xdbPath) : ICacheStrategy
 {
-    private readonly ReadOnlyMemory<byte> _cacheData;
+    // TODO: these constants can be moved to the interface as defaults when using .NET 10
+    private const int HeaderInfoLength = 256;
+    private const int VectorIndexSize = 8;
 
-    public ContentCacheStrategy(string xdbPath) : base(xdbPath)
+    private readonly ReadOnlyMemory<byte> _cacheData = File.ReadAllBytes(xdbPath);
+
+    public int IoCount => 0;
+
+    public void ResetIoCount()
     {
-        _cacheData = base.GetData(0, (int)XdbFileStream.Length);
-        XdbFileStream.Close();
-        XdbFileStream.Dispose();
+        // Do nothing
     }
 
-    public override ReadOnlyMemory<byte> GetData(long offset, int length) => _cacheData.Slice((int)offset, length);
+    public ReadOnlyMemory<byte> GetVectorIndex(int offset)
+        => _cacheData.Slice(HeaderInfoLength + offset, VectorIndexSize);
 
-    protected override void Dispose(bool disposing)
+    public ReadOnlyMemory<byte> GetData(long offset, int length) => _cacheData.Slice((int)offset, length);
+
+    public void Dispose()
     {
-        base.Dispose(false);
+        // Do nothing
     }
 }