C#无法将方法转换为非委托类型 [英] C# cannot convert method to non delegate type

问题描述

我有一个叫做Pin的类.

public class Pin
{
    private string title;

    public Pin() { }

    public setTitle(string title) {
        this.title = title;
    }
    public String getTitle()
    {
        return title;
    }
}

从另一个类中，我在List<Pin>引脚中添加Pins对象，从另一个类中，我要迭代List引脚并获取元素.所以我有这段代码.

From another class I add Pins objects in a List<Pin> pins and from another I want to iterate the List pins and get the elements. So I have this code.

foreach (Pin obj in ClassListPin.pins)
{
     string t = obj.getTitle;
}

使用此代码，我无法检索标题.为什么?

With this code I cannot retrieve the title. Why?

(注意:ClassListPin只是一个静态类，其中包含一些元素，其中之一是List<Pin>引脚)

(Note: ClassListPin is just a static class which contains some elements and one of these, is the List<Pin> pins)

推荐答案

您需要在方法调用后添加括号，否则编译器会认为您在谈论方法本身(委托类型)，而您正在真正在谈论该方法的返回值.

You need to add parentheses after a method call, else the compiler will think you're talking about the method itself (a delegate type), whereas you're actually talking about the return value of that method.

string t = obj.getTitle();

---

其他非必需信息

另外，看看属性.这样，您就可以像使用变量一样使用title，而在内部，它就像一个函数一样工作.这样，您不必编写函数getTitle()和setTitle(string value)，但是您可以这样做:

Also, have a look at properties. That way you could use title as if it were a variable, while, internally, it works like a function. That way you don't have to write the functions getTitle() and setTitle(string value), but you could do it like this:

public string Title // Note: public fields, methods and properties use PascalCasing
{
    get // This replaces your getTitle method
    {
        return _title; // Where _title is a field somewhere
    }
    set // And this replaces your setTitle method
    {
        _title = value; // value behaves like a method parameter
    }
}

或者您可以使用自动实现的属性，默认情况下将使用此属性:

Or you could use auto-implemented properties, which would use this by default:

public string Title { get; set; }

您将不必创建自己的后备字段(_title)，编译器将自行创建它.

And you wouldn't have to create your own backing field (_title), the compiler would create it itself.

此外，您可以更改属性访问器(获取器和设置器)的访问级别:

Also, you can change access levels for property accessors (getters and setters):

public string Title { get; private set; }

您可以像对待字段一样使用属性，即:

You use properties as if they were fields, i.e.:

this.Title = "Example";
string local = this.Title;

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