Rounding a Value in the WPF Binding

问题

I'm attempting to implement a progress bar with a textbox on top that also displays the progress %. However the percentage is fractional. Is it possible to round a value returned in the dataset via the binding or does it have to be done via the code behind?

<ProgressBar Grid.Row="2" Grid.ColumnSpan="2" Height="25" HorizontalAlignment="Stretch"  Margin="5,5,5,2" Name="pbProgressIndex" VerticalAlignment="Top" Width="Auto" Value="{Binding Path=ProgressIndex, Mode=OneWayToSource}" />
<TextBlock Grid.Row="2" Grid.ColumnSpan="2" Height="25" Name="txtProgressIndex" Text="{Binding Path=ProgressIndex, Mode=OneWayToSource}" Width="Auto" Foreground="Black" FontWeight="Bold" FontSize="14" FontFamily="Verdana" Padding="5" Margin="5,5,5,5" TextAlignment="Center" />

回答1:

Use the StringFormat Property of the Binding, eg.:

{Binding Path=ProgressIndex, Mode=OneWayToSource, StringFormat=2N}

回答2:

StringFormat={}{0:#.00}

it looks better to me;)

回答3:

In addition to the StringFormat in Femaref's answer you need to get rid of the Mode=OneWayToSource settings. That mode is for pushing values from a control to a bound object (like a ViewModel) without receiving updates made to the value from code, which is the opposite of what you're trying to do. You want the OneWay mode for these which happens to be the default for both the TextBlock.Text. ProgressBar.Value used TwoWay by default, which will still work fine in this case, but you can also set it to Mode=OneWay.

来源：https://stackoverflow.com/questions/3659747/rounding-a-value-in-the-wpf-binding