RegistryKey::OpenSubKey Method (String^, RegistryKeyPermissionCheck)
Retrieves the specified subkey for read or read/write access.
Assembly: mscorlib (in mscorlib.dll)
public: [ComVisibleAttribute(false)] RegistryKey^ OpenSubKey( String^ name, RegistryKeyPermissionCheck permissionCheck )
Parameters
- name
-
Type:
System::String^
The name or path of the subkey to create or open.
- permissionCheck
-
Type:
Microsoft.Win32::RegistryKeyPermissionCheck
One of the enumeration values that specifies whether the key is opened for read or read/write access.
Return Value
Type: Microsoft.Win32::RegistryKey^The subkey requested, or null if the operation failed.
| Exception | Condition |
|---|---|
| ArgumentNullException | name is null |
| ArgumentException | permissionCheck contains an invalid value. |
| ObjectDisposedException | The RegistryKey is closed (closed keys cannot be accessed). |
| SecurityException | The user does not have the permissions required to read the registry key. |
Rather than throwing an exception, this method returns null if the requested key does not exist.
If permissionCheck is RegistryKeyPermissionCheck::ReadWriteSubTree, the key is opened for reading and writing; if permissionCheck is RegistryKeyPermissionCheck::ReadSubTree or RegistryKeyPermissionCheck::Default, the key is opened for reading unless the parent key was opened with RegistryKeyPermissionCheck::ReadWriteSubTree.
In order to use the OpenSubKey method, you must have an instance of the RegistryKey class. To get an instance of RegistryKey, use one of the static members of the Registry class.
The following code example creates a subkey containing 100 key/value pairs and closes it. The example opens the subkey with Default, records the time it takes to read all the values, and closes the subkey. The example opens the subkey with ReadSubTree and records the time it takes to read all the values. Finally, the example computes and displays the percentage improvement.
for the ability to read the specified registry key. Associated enumeration: RegistryPermissionAccess::Read
for the ability to access the specified registry key if it is a remote key. Associated enumeration: SecurityPermissionFlag::UnmanagedCode
Available since 2.0