When run the following code, key is a null value.why? please help.

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VS2010

C#

private static string GetDllLocation()
       {
           RegistryKey key = Registry.LocalMachine;
           key = key.OpenSubKey(@"Software\LightScribe");
           if (key == null) throw new DllNotFound("LightScribe Libraries not found");

           return key.GetValue("LsPrintLauncher", string.Empty) as string;
       }

Posted 27-Jun-13 7:29am

WangLirnRen

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2 solutions

Solution 2

Apparently this can happen on 64bit machines. As you have .NET 4 (or higher) then have a look at the solution on this stackoverflow post[^]

Posted 27-Jun-13 8:21am

CHill60

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Sergey Alexandrovich Kryukov · Accepted Answer · 2013-06-27T07:37:00

Solution 1

Indeed, as documentation says the return value of Microsoft.Win32.RegistryKey.OpenSubKey can be null: http://msdn.microsoft.com/en-us/library/z9f66s0a.aspx[^].

If the key not found, it should be null, all correct. Why it can be a problem? Note that GetValue can also be null, and it does not have to be a string type.

—SA

Posted 27-Jun-13 7:37am

Sergey Alexandrovich Kryukov

Comments

WangLirnRen 27-Jun-13 13:59pm

hi,Sergey Alexandrovich Kryukov.The key of "RegistryKey key = Registry.LocalMachine;" is null.Can you help me??

Sergey Alexandrovich Kryukov 27-Jun-13 14:01pm

I already did. If it is null, it should be null. Use Regedit and check up.
—SA

Sergey Alexandrovich Kryukov 27-Jun-13 14:02pm

Wait a minute... Do you mean that the first line of your method gives null, always?
—SA

WangLirnRen 27-Jun-13 14:27pm

Yes

Sergey Alexandrovich Kryukov 28-Jun-13 0:27am

Hm... Maybe solution 2 resolves it...
—SA