WPF multibound textblock not updating
- by Superstringcheese
I want to create a program which calculates how long it will take to repeat a process a certain number of times. I've scaled this down a lot for this example.
So, I have some textboxes which are bound to properties in a class:
Count: <TextBox x:Name="txtCount" Text="{Binding Count, Mode=TwoWay}" Width="50"/>
Days: <TextBox x:Name="txtDays" Text="{Binding Days, Mode=TwoWay}" Width="50"/>
and a textblock which is multibound like so:
<TextBlock x:Name="tbkTotal">
<TextBlock.Text>
<MultiBinding StringFormat="Days: {0}, Count: {1}">
<Binding Path="Days" /> /* This isn't updating */
<Binding Path="Count" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
My DataContext is set in the Window1.xaml.cs file.
public Window1()
{
InitializeComponent();
Sample sample = new Sample();
this.DataContext = sample;
}
I can update the multibound textblock with the Count property just fine, but the Days property always shows 0, even though the Days input accurately reflects changes. I believe that this is because my accessors are different for Days - namely, the Set method. This class is in a different file.
public class Sample : INotifyPropertyChanged
{
private int _count;
private TimeSpan _span;
public int Count
{
get { return _count; }
set
{
_count = value;
NotifyPropertyChanged("Count"); /* Doesn't seem to be needed, actually */
}
}
public TimeSpan Span { get { return _span; } }
/* The idea is to provide a property for Days, Hours, Minutes, etc. as conveniences to the inputter */
public double Days
{
get { return _span.Days; }
set
{
TimeSpan ts = new TimeSpan();
double val = value > 0 ? value : 0;
ts = TimeSpan.FromDays(val);
_span.Add(ts);
NotifyPropertyChanged("Span"); /* Here I can only get it to work if I notify that Span has changed - doesn't seem to be aware that the value behind Days has changed. */
}
}
private void NotifyPropertyChanged(string property)
{
if (null != this.PropertyChanged)
{
PropertyChanged(this, new PropertyChangedEventArgs(property));
}
}
public Sample()
{
_count = 0;
_span = new TimeSpan();
}
public event PropertyChangedEventHandler PropertyChanged;
}
