我们使用依赖属性来确定控件的可见性。我们与我们的授权库一起执行此操作。因此,在我们的 xaml 中,代码如下所示:
<ListBoxItem x:Name="About"
Content="About Us"
AuthLib:Authorization.Visibility="WebUser"
Margin="10,5,10,5" />
<ListBoxItem x:Name="Accounting"
Content="Work Order Acct"
AuthLib:Authorization.Visibility="Admin, Accounting,Finance"
Margin="10,5,10,5" />
其中 WebUser 是任何经过身份验证的用户,显然会计/财务/管理员角色具有提升的特权。
我们已经在一个页面上进行了数十次调用,没有任何问题,但从来没有数百次。可能值得复制/粘贴,看看效果如何。
如果值得的话,这里是我们 Auth 库中的可见性属性:
#region Visibility
public static string GetVisibility(UIElement obj)
{
return (string)obj.GetValue(VisibilityProperty);
}
public static void SetVisibility(UIElement obj, string value)
{
obj.SetValue(VisibilityProperty, value);
}
/// Using a DependencyProperty as the backing store for requiresRole. This enables animation, styling, binding, etc...
public static readonly DependencyProperty VisibilityProperty = DependencyProperty.RegisterAttached(
"Visibility",
typeof(string),
typeof(Authorization),
new PropertyMetadata(Visibility_Callback));
// This callback will be invoked when some control will receive a value for your 'Visibility' property
private static void Visibility_Callback(DependencyObject source, DependencyPropertyChangedEventArgs e)
{
var uiElement = (UIElement)source;
if (App.IsAuthenticated)
{
RecalculateControlVisibility(uiElement);
}
else
{
EventHandler eh = null;
eh = delegate
{
RecalculateControlVisibility(uiElement);
};
App.Authenticated += eh;
RecalculateControlVisibility(uiElement);
}
}
private static void RecalculateControlVisibility(UIElement control)
{
//Authorization.UserHasRole() - is your code to check roles
if (Authorization.UserHasRole(GetVisibility(control)))
{
control.Visibility = Visibility.Visible;
}
else
{
control.Visibility = Visibility.Collapsed;
}
}
#endregion