How can I read binary data from registry to byte array

Question

I saved a byte array to registry using following code

Byte[] value = new byte[16]{
    0x4a,0x03,0x00,0x00, 
    0x45,0x02,0x00,0x00, 
    0xb7,0x00,0x00,0x00, 
    0x9d,0x00,0x00,0x00
};

RegistryKey key = Registry.CurrentUser.CreateSubKey(KeyName);
key.SetValue(@"Software\Software\Key", value, RegistryValueKind.Binary);

Here is the key created using above code:

[HKEY_CURRENT_USER\Software\Software\Key]  
    "LOC"=hex:4a,03,00,00,45,02,00,00,b7,00,00,00,9d,00,00,00

Now I want to read the same data back to byte array format. Following code can read the same data but the output is of type object.

RegistryKey key = Registry.CurrentUser.OpenSubKey(KeyName);
object obj =  key.GetValue(@"Software\Software\Key", value);

Here casting to byte[] does not work. I know I can use serializer or streams to achieve this task. I would like to know if there is an easier way to read data back to byte[] type (A two liner code)?

Please note this question is in C++

What is `Value` in your case? Just save the instance variable `value` as such and cast back. that should work.. — nawfal, Jan 17 '13 at 08:46
@nawfal, Thanks for your answer. It was my coding mistake. you cought my mistake. The object `Value` and `value` were different. That was the reason I was getting `Invalid Cast` error. I edited my question and I'm going to keep it for future reference. thanks again — AaA, Jan 17 '13 at 09:29

score 11 · Accepted Answer · answered Jan 17 '13 at 10:47

To write a byte array to registry use following code

Byte[] value = new byte[]{
    0x4a,0x03,0x00,0x00, 
    0x45,0x02,0x00,0x00, 
    0xb7,0x00,0x00,0x00, 
    0x9d,0x00,0x00,0x00
};

RegistryKey key = Registry.CurrentUser.CreateSubKey(KeyName);
key.SetValue(@"Software\AppName\Key", value, RegistryValueKind.Binary);

To Retrieve the data back from registry into Byte[] format use following:

RegistryKey key = Registry.CurrentUser.OpenSubKey(KeyName);
byte[] Data =  (byte[]) key.GetValue(@"Software\AppName\Key", value);

Note: CurrentUser is name of the root for your Key location and points to HKEY_CURRENT_USER

score -1 · Answer 2 · answered Jan 17 '13 at 09:03

-1

I test in VB.NET:

Dim obj As Object = key.GetValue("Software\Software\Key", value__1)`
Dim v As [Byte]() = CType(obj, Byte())`

and it works

so in C# should be:

Byte[] v = Convert.ToByte(obj);

answered Jan 17 '13 at 09:03

Antonio DB

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Thanks for your answer but `Convert.ToByte` returns a `single byte` – AaA Jan 17 '13 at 09:20

How can I read binary data from registry to byte array

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