Today, i read much information on android's multi-screen document. I doubt that android support multi-screen on QVGA, HVGA and WVGA when you use 'dp' unit on the xml layout.Does the android support the same density but different resolution? For example, i define a xml layout for mdip. Can this layout be used on 480x800 and 320x480 resolution?
Thank You.
To answer your question: Yes, that layout could be used on various resolutions.
If you're using density based layouts and drawables, they can be used across all kinds of screen sizes. Examples of mdpi (160):
They might be different resolutions, but the density is approximately the same (mdpi). If you want to create layouts for each specific screen size, you can use normal-mdpi, large-mdpi and xlarge-mdpi.
There's a lot of information available on the subject at the Android Developer site: http://developer.android.com/guide/practices/screens_support.html
I'd suggest you go ahead and do a lot of testing with the various SDK templates. That helped me a lot when I was in your situation.