Question

代码1

public class Human
{
    private string h_name = "";
    private string h_gender = "Male";
    private int h_age = 0;
    public string Name
    {
        get { return h_name; }
        set { h_name = value; }
    }
    public string Gender
    {
        get { return h_name; }
        set { h_name = value; }
    }
    public int Age
    {
        get { return h_age; }
        set { h_age = value; }
    }

}

代码2

public class Here
{
    public static void Main(String[] args)
    {
        Human hm = new Human();
        hm.Name = "Bill";
        hm.Gender = "Male";
        hm.Age = 20;
    }
}

现在，我想将变量“hm”用作String，其中hm将返回Name属性...类似于：

string person = hm;
Console.WriteLine(person + " has greeted you!");

我该怎么办？我应该进行延期还是什么？

我重写了ToString（）方法，是的，它适用于Console.WriteLine（）

但是现在，我想将它作为字符串存储在字符串变量

中

string person = hm;
Console.WriteLine(person);

我得到了这个

Cannot implicitly convert type 'Human' to 'string'

我也想在我的VB.NET程序中使用它，但是当我连接它时它给了我这个错误：

Operator '&' is not defined for types 'String' and 'Human'

Answer 1

您可以使用operator overloading声明从您的类型到implicit的{{1}}转换。但这是一个坏主意。我建议您在类中覆盖 string方法，然后您可以像这样输出：

ToString

还有关于如何覆盖Console.WriteLine(hm + " has greeted you!");方法

的良好文档

How To: Override the ToString Method (C# Programming Guide)

Answer 2

通过将以下内容添加到Human类中的隐式约定将起作用

public static implicit operator string(Human h)
    {
        return h.Name;
    }

虽然我认为最好的方法是覆盖ToString方法，如此

public override string ToString()
{
   return Name;
}

Answer 3

您可以覆盖ToString方法：

public class Human
{
    private string h_name = "";
    private string h_gender = "Male";
    private int h_age = 0;

    public string Name
    {
        get { return h_name; }
        set { h_name = value; }
    }

    public string Gender
    {
        get { return h_name; }
        set { h_name = value; }
    }

    public int Age
    {
        get { return h_age; }
        set { h_age = value; }
    }

    public override string ToString()
    {
        return Name;
    } 
}

Answer 4

覆盖ToString()方法。

public class Human
    {
    public override ToString() { return Name }

    private string h_name = "";
    private string h_gender = "Male";
    private int h_age = 0;
    public string Name
    {
        get { return h_name; }
        set { h_name = value; }
    }
    public string Gender
    {
        get { return h_name; }
        set { h_name = value; }
    }
    public int Age
    {
        get { return h_age; }
        set { h_age = value; }
    }
}

您的代码将如下所示：

Console.WriteLine(hm + " has greeted you!");

Answer 5

^{vb.net回答：}

由其他人说明，您需要定义转化operator。如果要支持字符串连接，则还需要定义&运算符。

Public Class Human

    Public Property Name As String

    Public Shared Widening Operator CType(value As Human) As String
        Return value.Name
    End Operator

    Public Shared Operator &(left As Human, right As String) As String
        Return (left.Name & right)
    End Operator

    Public Shared Operator &(left As String, right As Human) As String
        Return (left & right.Name)
    End Operator

    Public Overrides Function ToString() As String
        Return Me.Name
    End Function

End Class

如何将某个类用作String？

5 个答案: