使用字典键(作为字符串)在构造函数中设置变量

本文关键字：构造函数 变量 设置 字符串 字典 | 更新日期: 2023-09-27 17:55:57

与其对类构造函数进行大量重载，不如传入一个动态设置变量的Dictionary。

// Class definition
public class Project
{
    public DateTime LastModified;
    public string LoanName;
    public string LoanNumber;
    public int LoanProgram;
    public string ProjectAddress;
    ...
    // Project class constructor
    public Project(Dictionary<string, object> Dict)
    {
        foreach (KeyValuePair<string, object> entry in Dict)
        {
            // ie, when the Key is "LoanName", this.LoanName is set
            this.(entry.Key) = entry.Value;   // <-- Does not compile, obviously
        }
    }
}
// application code
...
Dictionary<string, object> dict = new Dictionary<string,object>();
dict.Add("LoanName", "New Loan Name");
dict.Add("LoanProgram", 1);
dict.Add("ProjectAddress", "123 Whatever Way");
Project p = new Project(dict);
...

在构造函数中，有没有办法使用字典键（字符串）来确定要设置的类成员？ 这可以通过反射以某种方式完成吗？

使用字典键(作为字符串)在构造函数中设置变量

这些字段已经是公开的...为什么不直接使用对象初始化语法？

var p = new Project() {
    LoanName = "New Loan Name",
    LoanProgram = 1,
    ProjectAddress = "123 Whatever Way"
};

public class Project
{
    public DateTime LastModified;
    public string LoanName;
    public string LoanNumber;
    public int LoanProgram;
    public string ProjectAddress;
    ...
    // Project class constructor
    public Project(Dictionary<string, object> Dict)
    {
        foreach (KeyValuePair<string, object> entry in Dict)
        {
           this.GetType().GetProperty(entry.Key).SetValue(this, entr.Value, null);
        }
    }
}

这似乎是一场维护噩梦，但您可以通过这种方式查找属性。

var prop = typeof(Project).GetProperty(entry.Key);

然后你可以像这样设置值。

prop.SetValue(this, entry.Value);

不过，您不会以这种方式进行编译时类型检查。

我建议查看默认参数。

例如

public Project(loanName = null, lastModified = null, loanNumber = null, loanProgram = 0, projectAddress = null)
{
    //Set them in here
}

我还建议使用公共属性而不是公共字段。例如

public DateTime LastModified { get; private set; } //Makes it so only inside the class LastModified can be set
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