如果绑定值不是“”，如何修改绑定以使其添加“ pts”？

Question

I am using a ViewModel to set the number of points on my display. Is there a way that I could modify this so that when the value of points is "0" or another not empty that it adds " pts" but when it's "" it still displays ""

    string _points;
    public string Points
    {
        get => _points;
        set => SetProperty(ref _points, value);
    }

Answer 1

Do a check if the _string is "0" before returning it to the view, in your Points property:

get => _points.Equals("0") ? "0 pts" : _points;

And to tidy it up, put it into a method:

public string ReturnPoints() =>  _points.Equals("0") ? "0 pts" : _points;

And then in your Points property:

string _points;
public string Points
{
    get => ReturnPoints();
    set => SetProperty(ref _points, value);
}

Answer 2

From your question, you can try this.

use string.IsNullOrEmpty method to check string whether empty, if no append pts to the end string, otherwise return "" .

string _points;
public string Points
{  
    get => !string.IsNullOrEmpty(_points) ? $"{_points} pts" : string.Empty;
    set => SetProperty(ref _points, value);
}

Answer 3

Based on replys from OP on my other answer.

public static Points _points { get; set; }

class Points
{
    private int? i; 

    public static implicit operator Points(int value)
    {
        return new Points { i.Value = value };
    }

    public static implicit operator string(Points value)
    {
         if(Value.i.HasValue)
             return value.i.Value.ToString();
          return "";
    }

     public static implicit operator int(Points value)
    {   
        return value.I.HasValue ?value.i.value : 0;
    }
}

and using the new Points struct:

_points += 2;         // 2
string s = points;    // "2"