Flex的array和arrayCollection的应用实例

ArrayCollection是flex中的数组集合类，它是很常用的，我们使用它时需要注意几个地方

 1。事件监听， ArrayCollection可以为它注册一个集合改变的监听事件(CollectionEvent.COLLECTION_CHANGE)，就是一旦ArrayCollection数组改变就会触发Event，不是所有情况的改变都会触发改变事件，如果集合当中的对象属性没有被绑定，那么你改变它的对象值也是不会触发事件的，在这种情况下你也许可能需要去将对象的属性进行绑定或者通过itemUpdated方法去管理对象值改变,除非集合的长度改变了,事件才会被触发

 2。对象删除， ArrayCollection的对象删除方法removeAll()，有这样一种情况，当你在过滤集合数据的时候，它并不会删除所有数据，而是删除全部过滤的数据，不符合过滤条件的数据就没被删除，依然还在source中

 3。过滤函数， ArrayCollection有个filterFunction过滤函数，就是可能集合中你只需要显示其中某几个对象，你将会需要根据对象条件筛选对象，那么你可能会用过滤函数，过滤函数会将不符合条件的对象过滤出来，但是ArrayCollection有个source属性是不会变的，它是个数组，所有源数据全在里面，尽管你去过滤，所有对象都会一直存在其中

 4。排序， ArrayCollection还有一个sort属性是用来排序的，你可以为其指定排序字段

Array
----------------------------------------------------------------
1.
<mx:Script><![CDATA[
    var myArray:Array = ["AK", "AL", "AR"];
]]></mx:Script>
2.
<mx:Array>
    <mx:String>AK</mx:String>
    <mx:String>AL</mx:String>
    <mx:String>AR</mx:String>
</mx:Array>
3.
<mx:Script><![CDATA[
    var expenses:Array = [
        {Month: "January", Profit: 2000, Expenses: 1500, Amount: 450},
        {Month: "February", Profit: 1000, Expenses: 200, Amount: 600},
        {Month: "March", Profit: 1500, Expenses: 500, Amount: 300},
        {Month: "April", Profit: 500, Expenses: 300, Amount: 500},
        {Month: "May", Profit: 1000, Expenses: 450, Amount: 250},
        {Month: "June", Profit: 2000, Expenses: 500, Amount: 700}
    ];
]]></mx:Script>
-----------------------------------------------------------------------

----------------------------------------------------------------------
// Use Array constructor.
var myArray:Array = new Array();
myArray.push("one");
myArray.push("two");
myArray.push("three");
trace (myArray); // output: one,two,three

// Use Array literal.
var myArray:Array = ["one", "two", "three"];
trace (myArray); // output: one,two,three
-----------------------------------------------------------------

----------------------------------------------------------------
var names:Array = new Array();
trace(names.length); // output: 0

var names:Array = new Array(3);
trace(names.length); // output: 3
trace(names[0]); // output: undefined
trace(names[1]); // output: undefined
trace(names[2]); // output: undefined

var names:Array = new Array("John", "Jane", "David");
trace(names.length); // output: 3
trace(names[0]); // output: John
trace(names[1]); // output: Jane
trace(names[2]); // output: David
-------------------------------------------------------------------

-----------------------------------------------------------------------
var planets:Array = new Array();
planets.push("Mars");       // array contents: Mars
planets.unshift("Mercury"); // array contents: Mercury,Mars
planets.splice(1, 0, "Venus", "Earth");
trace(planets);             // array contents: Mercury,Venus,Earth,Mars

var oceans:Array = ["Victoria", "Pacific", "Aral", "Superior", "Indian", "Huron"];
oceans.splice(2, 2, "Arctic", "Atlantic"); // replaces Aral and Superior
oceans.pop();   // removes Huron
oceans.shift(); // removes Victoria
trace(oceans); // output: Pacific,Arctic,Atlantic,Indian

var lakes:Array = oceans.splice(2, 2, "Arctic", "Atlantic");
trace(lakes); // output: Aral,Superior

var oceans:Array = ["Arctic", "Pacific", "Victoria", "Indian", "Atlantic"];
delete oceans[2];
trace(oceans);        // output: Arctic,Pacific,,Indian,Atlantic
trace(oceans[2]);     // output: undefined
trace(oceans.length); // output: 5

var oceans:Array = ["Arctic", "Pacific", "Victoria", "Aral", "Superior"];
oceans.length = 2;
trace(oceans); // output: Arctic,Pacific

var oceans:Array = ["Arctic", "Atlantic", "Indian", "Pacific"];
oceans.reverse();
trace(oceans); // output: Pacific,Indian,Atlantic,Arctic

var poets:Array = ["Blake", "cummings", "Angelou", "Dante"];
poets.sort(); // default sort
trace(poets); // output: Angelou,Blake,Dante,cummings

poets.sort(Array.CASEINSENSITIVE);
trace(poets); // output: Angelou,Blake,cummings,Dante

poets.sort(Array.DESCENDING);
trace(poets); // output: Dante,cummings,Blake,Angelou

poets.sort(Array.DESCENDING | Array.CASEINSENSITIVE); // use two options
trace(poets); // output: Dante,cummings,Blake,Angelou
----------------------------------------------------------------------------
var names:Array = new Array("John Q. Smith", "Jane Doe", "Mike Jones");
function orderLastName(a, b):int {
var lastName:RegExp = /\b\S+$/;
var name1 = a.match(lastName);
var name2 = b.match(lastName);
if (name1 < name2) {
    return -1;
} else if (name1 > name2) {
    return 1;
} else {
    return 0;
}
}
trace(names); // output: John Q. Smith,Jane Doe,Mike Jones
names.sort(orderLastName);
trace(names); // output: Jane Doe,Mike Jones,John Q. Smith
--------------------------------------------------------------------------

----------------------------------------------------------------------------
var poets:Array = new Array();
poets.push({name:"Angelou", born:"1928"});
poets.push({name:"Blake", born:"1757"});
poets.push({name:"cummings", born:"1894"});
poets.push({name:"Dante", born:"1265"});
poets.push({name:"Wang", born:"701"});

poets.sortOn("born", Array.NUMERIC);
for (var i:int = 0; i < poets.length; ++i) {
    trace(poets[i].name, poets[i].born);
}

var indices:Array;
indices = poets.sortOn("born", Array.NUMERIC | Array.RETURNINDEXEDARRAY);
for (var i:int = 0; i < indices.length; ++i) {
    var index:int = indices[i];
    trace(poets[index].name, poets[index].born);
}

---------------------------------------------------------------------

-----------------------------------------------------------------------
var array1:Array = ["alpha", "beta"];
var array2:Array = array1.concat("gamma", "delta");
trace(array2); // output: alpha,beta,gamma,delta

var array3:Array = array1.concat(array2);
trace(array3); // output: alpha,beta,alpha,beta,gamma,delta

var array4:Array = array3.slice(2,5);
trace(array4); // output: alpha,beta,gamma

var rivers:Array = ["Nile", "Amazon", "Yangtze", "Mississippi"];
var riverCSV:String = rivers.toString();
trace(riverCSV); // output: Nile,Amazon,Yangtze,Mississippi
var riverPSV:String = rivers.join("+");
trace(riverPSV); // output: Nile+Amazon+Yangtze+Mississippi

var nested:Array = ["b","c","d"];     
var letters:Array = ["a",nested,"e"];
var joined:String = letters.join("+");
trace(joined); // output: a+b,c,d+e
------------------------------------------------------------------

------------------------------------------------------------------

public dynamic class TypedArray extends Array {
    private const dataType:Class;

    public function TypedArray(...args) {
    }   
   
    AS3 override function concat(...args):Array {
    }
   
    AS3 override function push(...args):uint {
    }
   
    AS3 override function splice(...args) {
    }
   
    AS3 override function unshift(...args):uint {
    }
}   

------------------------------------------------------------------

public dynamic class Array {
    public function Array(...args) {
        var n:uint = args.length
        if (n == 1 && (args[0] is Number))
        {
            var dlen:Number = args[0];
            var ulen:uint = dlen
            if (ulen != dlen)
                throw new RangeError("Array index is not a 32-bit unsigned integer ("+dlen+")")
            length = ulen;
        }
        else
        {
            length = n;
            for (var i:int=0; i < n; i++) {
                this[i] = args[i]
            }
        }
    }   
}
-------------------------------------------------------------------------------------------------------
public dynamic class TypedArray extends Array {
    private var dataType:Class;
    public function TypedArray(typeParam:Class, ...args) {
        dataType = typeParam;
        var n:uint = args.length
        if (n == 1 && (args[0] is Number))
        {
            var dlen:Number = args[0];
            var ulen:uint = dlen
            if (ulen != dlen)
                throw new RangeError("Array index is not a 32-bit unsigned integer ("+dlen+")")
            length = ulen;
        }
        else
        {
            for (var i:int=0; i < n; i++) {
                // type check done in push()
                this.push(args[i])
            }
            length = this.length;
        }
    }   
}

-----------------------------------------------------------------------------------------------------  
AS3 override function push(...args):uint {
        for (var i:* in args) {
            if (!(args[i] is dataType)) {
                args.splice(i,1);
            }
        }
        return (super.push.apply(this, args));
    }
-----------------------------------------------------------------------------------------------------   
AS3 override function concat(...args):Array {
        var passArgs:TypedArray = new TypedArray(dataType);
        for (var i:* in args) {
            // type check done in push()
            passArgs.push(args[i]);
        }
        return (super.concat.apply(this, passArgs));
    }
-----------------------------------------------------------------------------------------------------   
AS3 override function splice(...args):* {
        if (args.length > 2) {
            for (var i:int=2; i< args.length; i++) {
                if (!(args[i] is dataType)) {
                    args.splice(i,1);
                }
            }
        }
        return (super.splice.apply(this, args));
    }
-------------------------------------------------------------------------
   AS3 override function unshift(...args):uint {
        for (var i:* in args) {
            if (!(args[i] is dataType)) {
                args.splice(i,1);
            }
        }
        return (super.unshift.apply(this, args));
    }