NumericTextBox change the double.NaN in to 0

Hi there, If the value of NumericTextBox is binding to the double value and the initial value is double.NaN, it automatically changed to 0 on display, which it is very perceptive.

The more serious problem is that If we really want to enter a value 0, it will not update the property bound undernearth, since the control did not think it is changed.

Can we have a property to set so it will display NaN or just allow the NaN or give the empty value?

you can reproduce this by changing the NumericTextBoxDemo.xaml/.cs by:

<ms:NumericTextBox Grid.Column="1" Grid.Row="2" Value="{Binding NanVal, Mode=OneWay}" DecimalPlaces="2" EnforceDecimalPlaces="False" FocusChangedBehavior="Round"
                         ValueChanged="NumericTextBox_ValueChanged" RangeConstraintMode="OnLostFocusOrReturn" />

public double NanVal
{
       get { return double.NaN; }
}

Hello Gordon

I'm sorry to say that the NumericTextBox only supports decimal values. Normally this is fine for double values, but in the case of Double.NaN, there is no way to even set the Value property. The WPF framework intercepts it first and changes it to the default value which is 0.

I've put this item on the backlog which may result in building a new control to support this. I hope there is some other work around you can use in the mean time.

Jason Fauchelle

Hi Jason,

The whole reason we turn into use NumericTextBox, is that the TextBox is not work well when we put it into DataGrid, see this thread. Is there possible to change it into empty value? Can we set the value converter at all?

Thanks

Gordon

Hello Gordon. I'll be exploring this issue again tomorrow.

Jason Fauchelle

Hello Gordon

Looks like setting a converter will not be an option. I tried to implement some internal trickery to make the NumericTextBox think it can handle Double.NaN, but it got too messy. Instead I'll implement a DoubleTextBox for you tomorrow.

Jason Fauchelle

Hello Gordon

The DoubleTextBox control is finished and will be available in the next nightly build. This includes Double.NaN support. At the moment, NaN can only be set programatically or through a binding. The user can not yet type "NaN" to set the value. Also, when NaN is displayed, they need to highlight the whole word to replace it with a number rather than backspacing it letter by letter. See the behavior for yourself when you install the next nightly build, and let me know if any of these details need to be implemented.

Jason Fauchelle

Hi Jason,

I downloaded Dec. 7's nightly build, it seemed not working either it is alone or put into DataGrid.

1) Run the application, look the Age data column, you cannot change the value.

2) On the bottom of window, I put the DoubleTextBox, it even does not show.

3) Do we need to put the license of DoubleTextBox in *.lic file? I don't know what to put there.

Please let me know what I did wrong.

Thanks Gordon

Hello Gordon

My apologies, there was a bug in the DoubleTextBox control which will be resolved in the next nightly build. This control does not have licensing, so don't worry about that.

Jason Fauchelle

Thanks Jason, it is working now

Gordon