如果我有basecontrol，如何阻止我的WPF用户控件加载

Question

I have a BaseControl, of which almost all my controls inherit from.

Right now I am working on security and I want to block users from viewing certain items if they do not have access.

I am able to do so on the Loaded event of the base control, but this is too late, this meanse the whole control gets rendered, and then replaced. I would like to replace it before it renders

here is an example of my code:

public class BaseControl : UserControl
{
    public BaseControl()
    {
        this.Loaded +=BaseControl_Loaded;
    }

    private void BaseControl_Loaded(object sender, RoutedEventArgs e)
    {

        if (!userHasAccess)
        {
            this.Content = new AccessDenied();
        }
    }
}

The above code works perfectly, but a bit too late, Is there a way that I can do this before the Loaded event?

Answer 1

You want to override the OnInitialized where the constructor and properties are being set up before the Render happens.

protected override void OnInitialized(EventArgs e)
{
  if (!userHasAccess)
  {
   this.Content = new AccessDenied();
  }
  base.OnInitialized(e);
}

More information can be found here .

Answer 2

Check out following sites:

http://msdn.microsoft.com/en-us/library/ms745025(v=vs.110).aspx

Also check object lifetime events that is what you asking for.

http://msdn.microsoft.com/en-us/library/ms754221(v=vs.110).aspx