Question

我可以通过以下方式动态更新列表，例如总金额= firstamount + secondamount吗？如果没有，最理想的方法是什么？

List<Test> test = new List<Test> 
{
    new Test 
    { 
        Name ="ABC",
        FirstAmount = 10,
        SecondAmount = 20,
        TotalAmount = FirstAmount + SecondAmount                                                                                                
    }
};    

public class Test
{
    public String Name { get; set; }

    public decimal FirstAmount { get; set; }

    public decimal SecondAmount { get; set; }

    public decimal TotalAmount { get; set; }
}

Answer 1

你可以改变你的对象，使其成为TotalAmount的吸气剂......类似于

List<Test> test = new List<Test> 
{
    new Test { Name ="ABC",FirstAmount =10,SecondAmount =20}
};

public class Test
{
    public String Name {set;get;}

    public decimal FirstAmount {set;get;}

    public decimal SecondAmount {set;get;}

    public decimal TotalAmount {get {return FirstAmount + SecondAmount;}}
}

Answer 2

如果你的总数总是其他两个的总和，你可以这样做：

List<Test> test = new List<Test> 
{
    new Test { Name ="ABC",FirstAmount =10,SecondAmount =20}
};

public class Test
{
    public String Name {set;get;}

    public decimal FirstAmount {set;get;}

    public decimal SecondAmount {set;get;}

    public decimal TotalAmount { get { return FirstAmount + SecondAmount; } }
}

Answer 3

不，除了设置它们之外，您无法访问正在初始化的对象的属性。

在这种情况下，最简单的解决方法是使用中间变量：

int firstAmount = 10;
int secondAmount = 20;

List<Test> test = new List<Test> 
{
    new Test { Name ="ABC",FirstAmount = firstAmount,SecondAmount = secondAmount ,TotalAmount = firstAmount + secondAmount}
};

Answer 4

另一种方法是使用构造函数：

List<Test> test = new List<Test> 
{
    new Test(
        name: "ABC",
        firstAmount: 10,
        secondAmount: 20                                                                                            
    )
};    

public class Test
{
    public Test(string name, decimal firstAmount, decimal secondAmount)
    {
        Name = name;
        FirstAmount = firstAmount;
        SecondAmount = secondAmount;
        TotalAmount = firstAmount + secondAmount;
    }

    public String Name { get; set; }

    public decimal FirstAmount { get; set; }

    public decimal SecondAmount { get; set; }

    public decimal TotalAmount { get; set; }
}

使用此方法，您的TotalAmount属性仍然可以编辑。

在对象初始化列表c＃中执行算术运算

4 个答案: