public virtual function ShouldCollide(fixtureA:b2Fixture, fixtureB:b2Fixture) : Boolean{

    var filter1:b2FilterData = fixtureA.GetFilterData();

    var filter2:b2FilterData = fixtureB.GetFilterData();

    if (filter1.groupIndex == filter2.groupIndex && filter1.groupIndex != 0)

    {

        return filter1.groupIndex > 0;

    }

    var collide:Boolean = (filter1.maskBits & filter2.categoryBits) != 0 && (filter1.categoryBits & filter2.maskBits) != 0;

    return collide;

}

var filter1={categoryBits:0x0001,maskBits:0xFFFF};

var filter2={categoryBits:0x0001,maskBits:0xFFFF};

var filter3={categoryBits:0x0001,maskBits:0xFFFF};

var filter4={categoryBits:0x0001,maskBits:0xFFFF};

var list:Array=[filter1,filter2,filter3,filter4];

filter1.categoryBits=1<<1;//

filter2.categoryBits=1<<2;//

filter3.categoryBits=1<<3;//

filter4.categoryBits=1<<4;//

filter1.maskBits=0|4|16;//只和4,16碰撞

//filter1.maskBits=~(4|16);//不和4,16碰撞

for(var i:int=0;i<1;i++){

    for(var j:int=0;j<list.length;j++){

        getCollide(list[i],list[j]);

    }

}

function getCollide(filter1:*,filter2:*):Boolean{

    var collide:Boolean = (filter1.maskBits & filter2.categoryBits) != 0 && (filter1.categoryBits & filter2.maskBits) != 0;

    trace("filter1.categoryBits:"+filter1.categoryBits, "filter1.maskBits:"+filter1.maskBits);

    trace("filter2.categoryBits:"+filter2.categoryBits, "filter2.maskBits:"+filter2.maskBits);

    trace("collide:"+collide);

    trace("______________________________________________________");

    return collide;

}

/*output:

filter1.categoryBits:2 filter1.maskBits:20

filter2.categoryBits:2 filter2.maskBits:20

collide:false

______________________________________________________

filter1.categoryBits:2 filter1.maskBits:20

filter2.categoryBits:4 filter2.maskBits:65535

collide:true

______________________________________________________

filter1.categoryBits:2 filter1.maskBits:20

filter2.categoryBits:8 filter2.maskBits:65535

collide:false

______________________________________________________

filter1.categoryBits:2 filter1.maskBits:20

filter2.categoryBits:16 filter2.maskBits:65535

collide:true

______________________________________________________

*//