WPF和C＃中路径格式化的绑定元素

Question

I'm user a custom user control that is a special type of slider. I can get the lower and upper values from the binding of the object like such:

{Binding ElementName=slider, Path=LowerValue};
{Binding ElementName=slider, Path=UpperValue};

I would like to reformat this number before putting into a Label . I've tried embedding some c# directly into my WPF, but I'm not sure how to get the values back in c#. Here's what I've tried which doesn't work:

<![CDATA[
                double min = {Binding ElementName=slider, Path=LowerValue};
                double max = {Binding ElementName=slider, Path=UpperValue};


                if (min == 1) { label.Content = "24:00:00"; }
                else { label.Content = TimeSpan.FromHours(min).ToString(@"hh\:mm\:ss"); }

                if (max == 1) { label_Copy.Content = "24:00:00"; }
                else { label_Copy.Content = TimeSpan.FromHours(max).ToString(@"hh\:mm\:ss"); }
            ]]>
    </x:Code>

Answer 1

This sort of thing is a lot easier if you use MVVM. Create a view model and add your two properties along with an update function:

public class TestViewModel : ViewModelBase
{
    private int _TimeVal;
    public int TimeVal
    {
        get { return this._TimeVal; }
        set
        {
            this._TimeVal = value;
            RaisePropertyChanged(() => this.TimeVal);
            UpdateText();
        }
    }

    private string _TimeText;
    public string TimeText
    {
        get { return this._TimeText; }
        set { this._TimeText = value; RaisePropertyChanged(() => this.TimeText); }
    }

    public TestViewModel()
    {
        UpdateText(); // force initial value
    }

    private void UpdateText()
    {
        this.TimeText = TimeSpan.FromHours(this.TimeVal).ToString(@"hh\:mm\:ss");
    }
}

Then in your XAML you simply bind to those properties:

<Slider Minimum="0" Maximum="100" Value="{Binding TimeVal}"/>
<TextBox Text="{Binding Path=TimeText}" />

Answer 2

1.Define a converter that casts the value as slider & returns the formatted text:

public class SliderToContentConverter:IValueConverter
{
  ....Convert(object value,...)
  {
     var slider =value as slider;
     if(slider!=null)
     {
      double min = slider.LowerValue;
      double max = slider.UpperValue;
      if (min == 1) 
         { return "24:00:00"; }
      else
         { return TimeSpan.FromHours(min).ToString(@"hh\:mm\:ss"); }
      if (max == 1) 
         { return "24:00:00"; }
      else {  return TimeSpan.FromHours(max).ToString(@"hh\:mm\:ss"); 
      }
     return null;
   }
}

2.Add the converter in Resources with a key.
3.Add binding for Label.Content:

<Label x:name=label_copy Content={Binding ElementName=slider,Converter={StaticResource con}/>

Answer 3

<slider LowerValue={Binding lval} UpperValue={Binding uval}/>

in c#

double _lval;
double lval
{
get
{
return _lval;
}
set
{
_lval=value;
}
}

value is what you want