属性,构造函数,枚举

如下示例类

public class People
{
    public bool View { get; set; }

    public bool Create { get; set; }

    public bool Edit { get; set; }

    public bool Delete { get; set; }
}

1.以属性填充方式进行

public void Test1()
{
    People entity = new People();
    entity.View = true;
    entity.Create = true;
    entity.Delete = false;
    entity.Edit = true;
}

2.以构造函数填充

public People(bool view, bool create, bool edit,bool delete)
{
    this.View = view;
    this.Create = create;
    this.Edit = edit;
    this.Delete = delete;
}

public void Test2()
{
    People entity = new People(true,true,true,false);
}

以此构造函数创建对象有如下缺点
（1）必须4个参数全部输入(不考虑c# 4.0缺省参数),必须重新构建新构造函数,如

public People(bool view, bool create)
{
    this.View = view;
    this.Create = create;
}

(2)构造函数一些容易造成混淆
有人说可以使用c#3.0语法,如下

public void Test3()
{
    People entity = new People() {Edit=true, Create=false };
}

以上方式比较灵活,但是如果我要将属性变更为私有属性,如

private bool View { get; set; }

private bool Create { get; set; }

private bool Edit { get; set; }

private bool Delete { get; set; }

但同时又想方便的在构造函数中设置参数,但又不要长长的构造器.这时候枚举就可以帮上忙

3.枚举

public People(PeoplePermissions options)
{
    _options = options;
}

private PeoplePermissions _options;

public void Test4()
{
    People entity = new People(PeoplePermissions.Create | PeoplePermissions.Delete);
}

枚举的操作还是比较麻烦的,用属性则比较友好,所以又可以用属性来包装枚举中的值,如

private bool Delete
{
    get
    {
        return ReadFlag(PeoplePermissions.Delete);
    }
    set
    {
        WriteFlag(PeoplePermissions.Delete, value);
    }
}

总结:
(1)构造函数中用枚举当参数非常方便
(2)取值非常麻烦
(3)封装成属性比较友好,但更费力气有好有坏吧,目前又想方便又想要属性,只能是这样了,否则是省掉第三步,但少了第三步,没有属性有时候代码写起来比较沮丧.
其实这个应用很广.WPF到处是这样的应用,FrameworkPropertyMetadata 就比较的典型