unity 会记录打出来的obb的hash在/assets/bin/Data/settings.xml 。修改obb或者想复用obb就需要修改apk内的hash字段。 用obb的最后65558个字节计算的hash

obb_md5_computer.cs

		public static string CalculateObbDigest(string file)
		{
			byte[] arrayOfByte = null;

			using (var localMessageDigest = MD5.Create())			
			using (var localFileInputStream = File.OpenRead(file))
			{
				long l1 = localFileInputStream.Length;
				localFileInputStream.Seek(l1 - Math.Min(l1, 65558L), SeekOrigin.Current);
				arrayOfByte = localMessageDigest.ComputeHash(localFileInputStream);			
			}

			var localStringBuffer = new StringBuilder(32);
			for (int i1 = 0; i1 < arrayOfByte.Length; i1++)
			{
				localStringBuffer.AppendFormat(arrayOfByte[i1].ToString("x2"));
			}
			return localStringBuffer.ToString();	
		}