从对象

Question

我有以下Class

public class BlogPost
{
    public int BlogPostId             { get; set; }
    public string BlogPostTitle       { get; set; }
    public string BlogPostDescription { get; set; }
    public int Upvotes    { get; set; }
    public int Downvotes  { get; set; }
    public int TotalVotes { get; set; }
}

您如何自动分配TotalVotes = Upvotes - Downvotes？

Answer 1

听起来你正在寻找calculated property。所以它应该是这样的：

public int TotalVotes
{ 
    get { return Upvotes - Downvotes; } 
}

或者，如果您使用的是C＃6+，可以使用expression body，如下所示：

public int TotalVotes => Upvotes - Downvotes;

Answer 2

您只需要在返回路径中编写您的操作，如：

public int TotalVotes { get { return Upvotes - Downvotes;} }

Answer 3

其他人的答案会奏效，但我更喜欢这样的事情（C＃6.0）

public class BlogPost
{
    public int BlogPostId { get; set; }
    public string BlogPostTitle { get; set; }
    public string BlogPostDescription { get; set; }
    public int Upvotes { get; set; }
    public int Downvotes { get; set; }
    public int TotalVotes {get => GetTotalVotes(); }   

    // A method just in case if you need to do some extra calculations or validations
    private int GetTotalVotes()
    {

        //I am assuming the TotalVotes should not go below 0;
        //You can change it as you like

        int value = UpVotes - DownVotes;

        return value<0? 0 : value;

    }
}