/// <summary>
/// Attempts to retrieve a valid license for the passed object instance.
/// </summary>
/// <param name="context">Context of this license indicating if it should be checked in runtime or compile time.</param>
/// <param name="type">Object type to retrieve license for.</param>
/// <param name="instance">Instance to check license of.</param>
/// <param name="allowExceptions">Determines if exceptions should be allowed. If true, a LicenseException
/// is thrown if no valid license can be obtained.</param>
/// <returns>Valid CustomLicense instance.</returns>
public override License GetLicense(LicenseContext context, Type type, object instance, bool allowExceptions)
{
var license = new CustomLicense(type);
// If we're not in runtime mode license should be automatically approved.
if (context.UsageMode != LicenseUsageMode.Runtime)
{
return(license);
}
// Get the intended registry key.
var registryKey = Registry.CurrentUser.OpenSubKey(license.RegistryKey);
// Get the registry key value.
var registryKeyValue = (string)registryKey?.GetValue(type.Name);
if (registryKeyValue != null)
{
// Confirm that the keyValue from registry is equivalent to expected LicenseKey.
if (string.CompareOrdinal(license.LicenseKey, registryKeyValue) == 0)
{
// All verification successful, so return the valid license.
return(license);
}
}
// If exceptions are allowed, return a LicenseException indicating that the license is not valid.
if (allowExceptions)
{
throw new System.ComponentModel.LicenseException(type, instance, $"The license of this {instance.GetType().Name} control is invalid.");
}
return(null);
}
/// <summary>
/// Deletes license registry entry for passed control type.
/// </summary>
/// <param name="type">Control type to delete license registry of.</param>
private static void DeleteLicenseRegistryEntry(Type type)
{
var license = new CustomLicense(type);
// Check if key exists.
var registryKey = Registry.CurrentUser.OpenSubKey(license.RegistryKey);
if (registryKey == null)
{
return;
}
// Delete key.
Registry.CurrentUser.DeleteSubKey(license.RegistryKey);
Logging.Log($"Deleted registry key: {Registry.CurrentUser}\\{license.RegistryKey}.");
}
/// <summary>
/// Adds license registry entry for passed control type.
/// </summary>
/// <param name="type">Control type to create license registry of.</param>
private static void AddLicenseRegistryEntry(Type type)
{
var license = new CustomLicense(type);
// Check if key exists.
var registryKey = Registry.CurrentUser.OpenSubKey(license.RegistryKey);
if (registryKey != null)
{
return;
}
// Set key value to license key.
var newKey = Registry.CurrentUser.CreateSubKey(license.RegistryKey);
newKey?.SetValue(type.Name, license.LicenseKey);
Logging.Log($"Added registry key value: {Registry.CurrentUser}\\{license.RegistryKey}\\{type.Name} = {license.LicenseKey}.");
}
