是否有可能在属性名传递作为字符串和值分配给它？ [英] Is it possible to pass in a property name as a string and assign a value to it?

问题描述

我设置了​​一个简单的辅助类来保存从文件中我分析一些数据。属性的名称相匹配，我希望找到的文件中值的名称。我想一个名为 AddPropertyValue 方法添加到我的课，这样我可以分配一个值的属性，而不按名称显式调用它。

I'm setting up a simple helper class to hold some data from a file I'm parsing. The names of the properties match the names of values that I expect to find in the file. I'd like to add a method called AddPropertyValue to my class so that I can assign a value to a property without explicitly calling it by name.

该方法是这样的：

//C#
public void AddPropertyValue(string propertyName, string propertyValue) {
   //code to assign the property value based on propertyName
}

---

'VB.NET'
Public Sub AddPropertyValue(ByVal propertyName As String, _
                            ByVal propertyValue As String)
    'code to assign the property value based on propertyName '
End Sub

的实施可能是这样的：

The implementation might look like this:

C＃/ VB.NET

C#/VB.NET

MyHelperClass.AddPropertyValue("LocationID","5")

这是可能的，而无需测试对每个单独的属性名称所提供的 propertyName的？

推荐答案

您可以做到这一点与反思，通过调用 Type.GetProperty 然后 PropertyInfo.SetValue 。你需要做适当的错误处理，检查的财产实际上并不存在present虽然。

You can do this with reflection, by calling Type.GetProperty and then PropertyInfo.SetValue. You'll need to do appropriate error handling to check for the property not actually being present though.

下面是一个示例：

using System;
using System.Reflection;

public class Test
{
    public string Foo { get; set; }
    public string Bar { get; set; }

    public void AddPropertyValue(string name, string value)
    {
        PropertyInfo property = typeof(Test).GetProperty(name);
        if (property == null)
        {
            throw new ArgumentException("No such property!");
        }
        // More error checking here, around indexer parameters, property type,
        // whether it's read-only etc
        property.SetValue(this, value, null);
    }

    static void Main()
    {
        Test t = new Test();
        t.AddPropertyValue("Foo", "hello");
        t.AddPropertyValue("Bar", "world");

        Console.WriteLine("{0} {1}", t.Foo, t.Bar);
    }
}

如果你需要做这个有很多，它可以成为在性能方面相当痛苦。大约有代表它可以使快了不少招数，但它的价值得到它的工作第一。

If you need to do this a lot, it can become quite a pain in terms of performance. There are tricks around delegates which can make it a lot faster, but it's worth getting it working first.

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