CODEWITHSUNDEEP
c#registry
Anudeep
Anudeep

Reputation: 347

How to retrieve the value from registry?

I want to retrieve the value from registry. For example like: HKEY_LOCAL_MACHINE\SOFTWARE\Manufacturer's name\Application name\InstallInfo

Under the 'InstallInfo' there are so many variables, like ProductVersion, WebsiteDescription, WebSiteDirectory, CustomerName, WebSitePort etc.

I want to retrieve some values of these variables. I tried the following code but it returns

'Object reference not set to an instance of an object'

        var regKey = Registry.LocalMachine;

        regKey = regKey.OpenSubKey(@"SOFTWARE\ABC Limited\ABC Application\InstallInfo");

        if (regKey == null)
        {
           Console.WriteLine("Registry value not found !");
        }
        else
        {
            string dirInfo = (string)regKey.GetValue("WebSiteDirectory");
            Console.Write("WebSiteDirectory: " + dirInfo);
        }


        Console.ReadKey();

Upvotes: 1

Views: 401

Answers (3)

Maryam Arshi
Maryam Arshi

Reputation: 2024

Before you convert regKey.GetValue("WebSiteDirectory") to string, You should check it if it is null or not,

if (regKey.GetValue("WebSiteDirectory")!=null)
 //do the rest

Upvotes: 1

David Heffernan
David Heffernan

Reputation: 613481

OpenSubKey returns null when it fails. That's clearly what's happening here.

It's failing because you are looking under the wrong root key. You are looking under HKCU but the key is under HKLM.

So you need

RegistryKey regKey = Registry.LocalMachine.OpenSubKey(
    @"SOFTWARE\Manufacturer's name\Application name\InstallInfo");

You must always check the return value when you call OpenSubKey. If it is null then handle that error case.

if (regKey == null)
    // handle error, raise exception etc.

The other thing to watch out for is the registry redirector. If your process is a 32 bit process running on a 64 bit system, then you will see the 32 bit view of the registry. That means that your attempt to view HKLM\Softare is transparently redirected to HKLM\Software\Wow6432Node.

Upvotes: 5

Vishal Suthar
Vishal Suthar

Reputation: 17194

It may be because you are looking under wrong root key.

It should be:

Registry.CurrentUser

instead of 

Registry.LocalMachine

Here you go: 

Registry.LocalMachine.CreateSubKey(@"SOFTWARE\Manufacturer's name\Application name\InstallInfo");

Upvotes: 0

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