[wpf] DataTrigger where value is NOT null?

You can use an IValueConverter for this:

<TextBlock>
    <TextBlock.Resources>
        <conv:IsNullConverter x:Key="isNullConverter"/>
    </TextBlock.Resources>
    <TextBlock.Style>
        <Style>
            <Style.Triggers>
                <DataTrigger Binding="{Binding SomeField, Converter={StaticResource isNullConverter}}" Value="False">
                    <Setter Property="TextBlock.Text" Value="It's NOT NULL Baby!"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </TextBlock.Style>
</TextBlock>

Where IsNullConverter is defined elsewhere (and conv is set to reference its namespace):

public class IsNullConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return (value == null);
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new InvalidOperationException("IsNullConverter can only be used OneWay.");
    }
}

A more general solution would be to implement an IValueConverter that checks for equality with the ConverterParameter, so you can check against anything, and not just null.

Examples related to wpf

Error: the entity type requires a primary key Reportviewer tool missing in visual studio 2017 RC Pass command parameter to method in ViewModel in WPF? Calling async method on button click Setting DataContext in XAML in WPF How to resolve this System.IO.FileNotFoundException System.Windows.Markup.XamlParseException' occurred in PresentationFramework.dll? Binding an Image in WPF MVVM How to bind DataTable to Datagrid Setting cursor at the end of any text of a textbox

Examples related to xaml

Setting DataContext in XAML in WPF Change color of Button when Mouse is over Implement Validation for WPF TextBoxes Use StringFormat to add a string to a WPF XAML binding How to format number of decimal places in wpf using style/template? How to set DataGrid's row Background, based on a property value using data bindings WPF C# button style How to clear a textbox once a button is clicked in WPF? Add Items to Columns in a WPF ListView Binding ConverterParameter

Examples related to binding

Binding ComboBox SelectedItem using MVVM Binding List<T> to DataGridView in WinForm Angularjs Template Default Value if Binding Null / Undefined (With Filter) Bootstrap control with multiple "data-toggle" How does the 'binding' attribute work in JSF? When and how should it be used? WPF Binding to parent DataContext How to get evaluated attributes inside a custom directive How can I use a C++ library from node.js? bind/unbind service example (android) Datagrid binding in WPF

Examples related to visibility

document.getElementById("remember").visibility = "hidden"; not working on a checkbox Calling the base class constructor from the derived class constructor Equivalent of jQuery .hide() to set visibility: hidden Making a button invisible by clicking another button in HTML Why is visible="false" not working for a plain html table? Make one div visible and another invisible Animate visibility modes, GONE and VISIBLE How to change visibility of layout programmatically How can I make visible an invisible control with jquery? (hide and show not work) How to check visibility of software keyboard in Android?

Examples related to datatrigger

How can I provide multiple conditions for data trigger in WPF? DataTrigger where value is NOT null?