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<HEAD>
<TITLE> 关于js的接口和 继承实现的代码例子 </TITLE>
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<script>
  function Interface(name, methods)
{
    if(arguments.length != 2) {
        throw new Error("接口构造函数含" + arguments.length + "个参数, 但需要2个参数.");
    }
    this.name = name;
    this.methods = [];
    if(methods.length < 1) {
        throw new Error("第二个参数为空数组.");
    }
    for(var i = 0, len = methods.length; i < len; i++) {
        if(typeof methods[i][0] !== 'string') {
            throw new Error("接口构造函数第一个参数必须为字符串类型.");
        }
        if(methods[i][1] && typeof methods[i][1] !== 'number') {
            throw new Error("接口构造函数第二个参数必须为整数类型.");
        }
        if(methods[i].length == 1) {
            methods[i][1] = 0;
        }

        this.methods.push(methods[i]);
    }   
};

Interface.registerImplements = function(object) {

    if(arguments.length < 2) {
        throw new Error("接口的实现必须包含至少2个参数.");
    }

    for(var i = 1, len = arguments.length; i < len; i++) {
        var interface = arguments[i];
        if(interface.constructor !== Interface) {
            throw new Error("从第2个以上的参数必须为接口实例.");
        }
        for(var j = 0, methodsLen = interface.methods.length; j < methodsLen; j++) {
            var method = interface.methods[j][0];
            if(!object[method] || typeof object[method] !== 'function' || object[method].getParameters().length != interface.methods[j][1]) {
                throw new Error("接口的实现对象不能执行" + interface.name + "的接口方法" + method + ",因为它找不到或者不匹配.");
            }
        }
    }
};

Function.prototype.getParameters = function() {

    var str = this.toString();
    var paramString = str.slice(str.indexOf('(') + 1, str.indexOf(')')).replace(/\s*/g,'');     //取得参数字符串
    try
    {
        return (paramString.length == 0 ? [] : paramString.split(','));
    }
    catch(err)
    {
        throw new Error("函数不合法!");
    }
}

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<script type="text/javascript">
var Person = new Interface("Person", [["getName", 0], ["setName", 1]]);
function Man()
{
    Interface.registerImplements(this, Person);
}
Man.prototype.name='';
Man.prototype.getName = function() {
    return this.name;
};
Man.prototype.setName = function(name) {
    this.name = name;
};
function test()
{
    var man = new Man();
    man.setName("Leepy");
    alert(man.getName());
}

///下面关于继承的代码是
function SchoolBoy(classNo, post)
{
    Man.call(this);
    this._chassNo = classNo;
    this._post = post;
}
SchoolBoy.prototype = new Man();
SchoolBoy.prototype.getName = function() {
    return "Mr " + this.name;
}
SchoolBoy.prototype.setName = function(name) {
    this.name = name + "'s";
};
var schoolboy = new SchoolBoy("三年二班", "班长");
schoolboy.setName("周杰伦");

function jic()
{
  alert(schoolboy.getName());
}
</script>

<input type="button" value="js接口的实现" onclick="test();" />
<br>
<input type="button" value="js的继承" onclick="jic()" />
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</HTML>

 posted on 2009-02-20 00:11 落叶满长沙 阅读(...) 评论(...) 编辑 收藏