Resize WPF Window and contents depening on screen resolution

Question

I have a WPF app with multiple controls on each window, some overlayed etc, what i need is a way of getting the app to resize itself automatically depending on the screen resolution.

Any ideas ?

Answer 1

The syntax Height="{Binding SystemParameters.PrimaryScreenHeight}" provides the clue but doesn't work as such. SystemParameters.PrimaryScreenHeight is static, hence you shall use:

  <Window x:Class="MyApp.MainWindow"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:tools="clr-namespace:MyApp.Tools"
      Height="{x:Static SystemParameters.PrimaryScreenHeight}" 
      Width="{x:Static SystemParameters.PrimaryScreenWidth}" 
      Title="{Binding Path=DisplayName}"
      WindowStartupLocation="CenterScreen"
      Icon="icon.ico"
  >

And it would fit the whole screen. Yet, you may prefer to fit a percentage of the screen size, e.g. 90%, in which case the syntax must be amended with a converter in a binding spec:

  <Window x:Class="MyApp.MainWindow"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:tools="clr-namespace:MyApp.Tools"
      Height="{Binding Source={x:Static SystemParameters.PrimaryScreenHeight}, Converter={tools:RatioConverter}, ConverterParameter='0.9' }" 
      Width="{Binding Source={x:Static SystemParameters.PrimaryScreenWidth}, Converter={tools:RatioConverter}, ConverterParameter='0.9' }" 
      Title="{Binding Path=DisplayName}"
      WindowStartupLocation="CenterScreen"
      Icon="icon.ico"
  >

Where RatioConverter is here declared in MyApp.Tools namespace as follows:

namespace MyApp.Tools {

    [ValueConversion(typeof(string), typeof(string))]
    public class RatioConverter : MarkupExtension, IValueConverter
    {
      private static RatioConverter _instance;

      public RatioConverter() { }

      public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
      { // do not let the culture default to local to prevent variable outcome re decimal syntax
        double size = System.Convert.ToDouble(value) * System.Convert.ToDouble(parameter,CultureInfo.InvariantCulture);
        return size.ToString( "G0", CultureInfo.InvariantCulture );
      }

      public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
      { // read only converter...
        throw new NotImplementedException();
      }

      public override object ProvideValue(IServiceProvider serviceProvider)
      {
        return _instance ?? (_instance = new RatioConverter());
      }

    }
}

Where the definition of the converter shall inherit from MarkupExtension in order to be used directly in the root element without a former declaration as a resource.

Answer 2

Just simply make a binding like that:

<Window x:Class="YourApplication.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="YourApplication" 
    Height="{Binding SystemParameters.PrimaryScreenHeight}" 
    Width="{Binding SystemParameters.PrimaryScreenWidth}">

Answer 3

Based on berhauz's answer. But you can simplify it even further by doing it in code behind(.xaml.cs):

public Window1()
{
    InitializeComponent();
    this.Height = SystemParameters.PrimaryScreenHeight * 0.95;
    this.Width = SystemParameters.PrimaryScreenWidth * 0.95;
}

Answer 4

Slightly improved version of @berhauz's answer. Uses modern pattern-matching and omits string-to-double-to-string conversion:

[ValueConversion(typeof(double), typeof(double))]
public class RatioConverter : MarkupExtension, IValueConverter
{
  private static RatioConverter _instance;

  public RatioConverter() { }

  public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
  {
    if (value == null || parameter is null)
      return null;
    else if (value is double v && parameter is double p)
      return v * p;
    else
      throw new ArgumentException("Both value and parameter must be of type double.");
}

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

  public override object ProvideValue(IServiceProvider serviceProvider)
  {
    return _instance ?? (_instance = new RatioConverter());
  }
}

Use it like this:

<Window.Width>
  <Binding Source="{x:Static SystemParameters.PrimaryScreenWidth}" Converter="{local:RatioConverter}">
    <Binding.ConverterParameter>
      <sys:Double>0.9</sys:Double>
    </Binding.ConverterParameter>
  </Binding>
</Window.MaxWidth>