MinValue & MaxValue attribute for properties

Question

Is it possible to make attribute which can limit minimum or maximum value of numbers.

Example:

[MinValue(1), MaxValue(50)]
public int Size { get; set         


        

Answer 1

You can elegantly solve this problem by using PostSharp by writing simple aspect, free version will be enough for this purpose:

[Serializable]
class RangeAttribute : LocationInterceptionAspect 
{
    private int min;
    private int max;

    public RangeAttribute(int min, int max)
    {
        this.min = min;
        this.max = max;
    }

    public override void OnSetValue(LocationInterceptionArgs args)
    {
        int value = (int)args.Value;
        if (value < min) value = min;
        if (value > max) value = max;            
        args.SetNewValue(value);
    }
}

and then exacly as you want:

class SomeClass
{
    [Range(1, 50)]
    public int Size { get; set; }
}

with normal usage:

var c = new SomeClass();
c.Size = -3;
Console.Output(c.Size);

will output 1.