How to disable WPF Menu's transparency?

I am writing an WPF application with a menu. it needs 2 to 4 seconds to show the submenu. during that 2～4 seconds, the submenu showed in transparency state.

So here is the Question, H开发者_开发技巧ow Can I disable the transparency state of the menu? or something to avoid the 2~4 seconds' delay?

Thanks in advance.

In the worst case scenario, you'll probably want to disable hardware acceleration at all: Ugly WPF text rendering - can't disable hardware acceleration on Vista

Is the issue because the menu fades in when clicked, but displays immediately when using a shortcut key, and the fading is slow? When I've seen problems like this, I've updated the video drivers and it's usually helped.

If you want to disable fading altogether, you could override the menu control templates and specify that the popup doesn't use any animation.