Use Stringformat to Add a String to a Wpf Xaml Binding

Use StringFormat to add a string to a WPF XAML binding

Your first example is effectively what you need:

<TextBlock Text="{Binding CelsiusTemp, StringFormat={}{0}°C}" />

StringFormat on Binding

The best and the easiest way would be to use a converter to which you pass the Date and get the formatted string back. In e.g. MyNamespace.Converters namespace:

public class DateFormatConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, string language)
    {
        if (value == null)
            return null;

        DateTime dt = DateTime.Parse(value.ToString());
        return dt.ToString("dd/MM/yyyy");
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotSupportedException();
    }
}

And in your xaml just reference the converter and add the following converter:

xmlns:conv="using:MyNamespace.Converters" 

in your xaml page and in page.resources add this

<conv:DateFormatConverter x:Name="DateToStringFormatConverter"/>

<TextBlock Text="{Binding Date, Converter={StaticResource DateToStringFormatConverter}"/>

String format for binding text in WPF

Here are two ways you can do it, one with a converter and one without.

"Text1" and "Text2" in the bindings are properties of the DataContext.

You will need to change the "MainText" to be a property:

public static string MainText { get; set; } = "Test: {0} Test2: {1}";

Without a converter:

<Label>
    <Label.Content>
        <TextBlock>
            <TextBlock.Text>
                <MultiBinding StringFormat="{x:Static local:MainWindow.MainText}">
                    <Binding Path="Text1" />
                    <Binding Path="Text2" />
                </MultiBinding>
            </TextBlock.Text>
        </TextBlock>
    </Label.Content>
</Label>

With a converter:

<Label>
    <Label.Resources>
        <local:TextFormatConverter x:Key="TextFormatConverter" />
    </Label.Resources>
    <Label.Content>
        <MultiBinding Converter="{StaticResource TextFormatConverter}" ConverterParameter="{x:Static local:MainWindow.MainText}">
            <Binding Path="Text1" />
            <Binding Path="Text2" />
        </MultiBinding>
    </Label.Content>
</Label>

And the converter:

public class TextFormatConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        string fmt = parameter as string;
        if (!string.IsNullOrWhiteSpace(fmt))
            return string.Format(fmt, values);
        return null;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

Binding String Format

You cannot bind StringFormat at all. StringFromat is not dependency property and therefore it is not bindable. If you want to achive this you have to do it in code behind or in case you use a MVVM pattern yu should do it in the view model. You can alo try this solution which uses MultiBinding. See this link.

xaml specific StringFormat Binding

You simply need to append ' EUR' to the StringFormat.

Text="{Binding MyProp, StringFormat={}{0:N2} EUR}"

To add the converter culture to get commas instead of periods, again you can add EUR to the format string.

Text="{Binding MyProp, StringFormat={}{0:N2} EUR, ConverterCulture=de-DE}"

Add newline to Stringformat in XAML

Set the TextBlock's Inlines property:

<TextBlock DataContext="{Binding DataContext.Week.Days[1].Date,
                         RelativeSource={RelativeSource AncestorType=DataGrid}}">
    <Run Text="{Binding Mode=OneWay, StringFormat=ddd}"/>
    <LineBreak/>
    <Run Text="{Binding Mode=OneWay, StringFormat=dd.MM.yyyy}"/>
</TextBlock>

StringFormat in XAML

It seems that, similar to Binding in WinRT, Binding in Windows Phone Universal Apps doesn't have StringFormat property. One possible way to work around this limitation is using Converter as explained in this blog post,

To summarize the post, you can create an IValueConverter implmentation that accept string format as parameter :

public sealed class StringFormatConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, string language)
    {
        if (value == null)
            return null;

        if (parameter == null)
            return value;

        return string.Format((string)parameter, value);
    }

    public object ConvertBack(object value, Type targetType, object parameter,
        string language)
    {
        throw new NotImplementedException();
    }
}

Create a resource of above converter in your XAML, then you can use it like this for example :

<TextBlock x:Name="countTextBlock" 
           Text="{Binding Count, 
                          Converter={StaticResource StringFormatConverter},
                          ConverterParameter='{}{0:n}'}" />

Binding StringFormat

Since BindingBase.StringFormat is not a dependency property, I do not think that you can bind it. If the formatting string varies, I'm afraid you will have to resort to something like this

<TextBlock Text="{Binding MyFormattedProperty}" />

and do the formatting in your view model. Alternatively, you could use a MultiBinding and a converter (example code untested):

<TextBlock>
    <TextBlock.Text>
        <MultiBinding Converter="{StaticResource myStringFormatter}">
            <Binding Path="MyProperty" />
            <Binding Path="MyFormatString" />
        </MultiBinding>
    </TextBlock.Text>
</TextBlock>

public class StringFormatter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        return string.Format((string)values[1], values[0]);
    }
    ...
}

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