Bind textbox to float value. Unable to input dot / comma

Question

When I try to input a DOT or a COMMA in a textbox, for example 1.02 or 83,33 the textbox prevents me to input such a value (and the input turns red). The textbox is bound to a float property. Why?

I have bound a textbox to a float Property Power of a class implementing INotifyPropertyChanged.

private float _power;

public float Power
{
    get { return _power; }
    set
    {
        _power = value;
        OnPropertyChanged("Power");
    }
}

In Xaml

<TextBox Name="txtPower" Height="23" TextWrapping="Wrap" Text="{Binding Path=Power, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"></TextBox>

I have no custom validation at all right now.

Also tried decimal but it does not work either. For string everything works fine.

Answer 1

If you have .NET 4.5 or newer, you may enforce the pre 4.5 behaviour

System.Windows.FrameworkCompatibilityPreferences.KeepTextBoxDisplaySynchronizedWithTextProperty = false;

See Sebastian Lux's blog: With .NET 4.5 it is no longer possible to enter a separator character (comma or dot) with UpdateSourceTrigger = PropertyChanged by default. Microsoft says, this intended.

Answer 2

Try adding a StringFormat definition to the binding. Like so:

<TextBox Name="txtPower" Height="23" 
    TextWrapping="Wrap" Text="{Binding Path=Power, Mode=TwoWay, 
    UpdateSourceTrigger=PropertyChanged,StringFormat=N2}"></TextBox>

Answer 3

to fix dot and comma issue in textbox binding to decimal or float

1-  UpdateSourceTrigger = LostFocus 
2-  add string format StringFormat={}{0:#.##} to escape unneeded zeros 


<TextBox Name="txtPower" Height="23" 
         TextWrapping="Wrap" Text="{Binding Path=Power, Mode=TwoWay, 
         UpdateSourceTrigger=LostFocus ,StringFormat={}{0:#.##}}"></TextBox>