[c#] How to load image to WPF in runtime?

Make sure that your sas.png is marked as Build Action: Content and Copy To Output Directory: Copy Always in its Visual Studio Properties...

I think the C# source code goes like this...

Image image = new Image();
image.Source = (new ImageSourceConverter()).ConvertFromString("pack://application:,,,/Bilder/sas.png") as ImageSource;

and XAML should be

<Image Height="200" HorizontalAlignment="Left" Margin="12,12,0,0" 
       Name="image1" Stretch="Fill" VerticalAlignment="Top" 
       Source="../Bilder/sas.png"
       Width="350" />  

EDIT

Dynamically I think XAML would provide best way to load Images ...

<Image Source="{Binding Converter={StaticResource MyImageSourceConverter}}"
       x:Name="MyImage"/>

where image.DataContext is string path.

MyImage.DataContext = "pack://application:,,,/Bilder/sas.png";

public class MyImageSourceConverter : IValueConverter
{
    public object Convert(object value_, Type targetType_, 
    object parameter_, System.Globalization.CultureInfo culture_)
    {
        return (new ImageSourceConverter()).ConvertFromString (value.ToString());
    }

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

Now as you set a different data context, Image would be automatically loaded at runtime.