为什么我的价值观不被保留一个类型的实例之间？ [英] Why are my values not being kept between instances of a type?

问题描述

我有类：

public class pro {
    private string url = string.Empty;
    public string GetURL() { return url; }
    public void SetURL(string value) { url = value; }
}

在这行我得到值：

string url = li1.Value;  

pro itm = new pro();  // I have create Proprtie so I'm calling that

itm.SetURL(url); // here I'm setting value

再后来：

pro itm = new pro(); //properties object I have created

string url = itm.GetURL(); // I'm not getting value which I have set in first 

类。

我有企业的性质创建还;我究竟做错了什么？

I have create Proprties also; what am I doing wrong?

推荐答案

每一个类实例（即每新款Pro（））有不同的实例值;它完美地预计，如果你有2个不同的实例，那么他们将不会分享网​​址，例如。如果你想分享这一点，你应该在相同 亲实例可以在两个地方，通过传递亲左右。

Every class instance (i.e. every new pro()) has different instance values; it is perfectly expected that if you have 2 different instances, then they will not share a URL, for example. If you want to share this, you should make the same pro instance available to both places, by passing the pro around.

顺便说一句，的GetURL（） / SetURL（）不是地道的C＃ - 这将是更为常见的有一个的属性的，即

Incidentally, GetURL() / SetURL() is not idiomatic C# - it would be more common to have a property, i.e.

public string Url {get;set;}

您会然后访问为：

which you would then access as:

YourType item = new YourType();
item.Url = "http://foo.com/bar/";
// ... 
string url = item.Url;

---

从注​​释，它的声音的就像你正在谈论静态的数据;我要强调的是，使用静态这通常不是一个好主意，并可能导致大量的与测试，多租户，线程等问题;但是：下列作品无任何实例：

---

From the comments, it sounds like you are talking about static data; I should emphasise that using static for this is not usually a good idea, and can lead to lots of problems with testing, multi-tenancy, threading, etc; but: the following works without any instances:

public class Properties {
    public static string Url {get;set;}
}
...
Properties.Url = "http://foo.com/bar/";
...
string url = Properties.Url;

请注意：完全没有实例

然而，它几乎总是preferable简单地保持一个的实例可用，并用实例属性针对常见的实例。

However, it is almost always preferable to simply keep an instance available, and use instance properties against that common instance.

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