NET 4.5 中新增的特性调用者信息特性CallerMemberNameAttribute/CallerFilePathAttribute/CallerLineNumberAttribute

标题中所说的三个特性 CallerMemberNameAttribute / CallerFilePathAttribute / CallerLineNumberAttribute 我们统称为调用者信息特性，正常情况下在 .NET Framework 4.0 中是无法使用的。

  static void Main( string[] args )
    {
        var productInfo = new ProductInfo();

        productInfo.Name = "lumia";

        productInfo.PropertyChanged();

        Console.ReadKey( true );
    }
}

public class ProductInfo
{
    private string _name;

    public string Name
    {
        get { return this._name; }
        set
        {
            this._name = value;
            this.PropertyChanged();
        }
    }

    public void PropertyChanged([CallerMemberName]string name = "", [CallerLineNumber]int line = 0, [CallerFilePath]string file = "")
    {
        Console.WriteLine("------------------------------------------------");
        Console.WriteLine($"Name : {name}, 
Line : {line}, 
Path : {file}");
    }
}

在 .NET Framework 4.0 中使用需要自己定义这三个特性

namespace System.Runtime.CompilerServices
{
    [AttributeUsage(AttributeTargets.Parameter, Inherited = false)]
    public class CallerMemberNameAttribute : Attribute
    {

    }

    [AttributeUsage(AttributeTargets.Parameter, Inherited = false )]
    public class CallerFilePathAttribute : Attribute
    {

    }

    [AttributeUsage(AttributeTargets.Parameter, Inherited = false )]
    public class CallerLineNumberAttribute : Attribute
    {

    }
}