Resolution Free Application

What is meant by the Resolution free application, As I have discus开发者_StackOverflow中文版sed it with many of my friend and they says that resolution free mean what ever resolution user want to see an application it should adjust it position, the resolultion is monitor resolution or any say 100 by 100 what is resolution?

Ideally, applications would use higher pixel densities to show more detail. For example, a high-resolution monitor could display similarly sized toolbar icons but use the extra pixels to render sharper graphics. That way you could keep the same basic layout but offer increased clarity and detail. For a variety of reasons, this solution hasn’t been possible in the past. Although you can resize graphical content that’s drawn with GDI/GDI+, User32 (which generates the visuals for common controls) doesn’t support true scaling.

WPF doesn’t suffer from this problem because it renders all user interface elements itself, from simple shapes to common controls such as buttons. As a result, if you create a button that’s 1 inch wide on your computer monitor, it can remain 1 inch wide on a high-resolution monitor—WPF will simply render it in greater detail and with more pixels.

WPF bases its scaling on the system DPI setting, not the DPI of your physical display device. It uses the system DPI setting when it calculates sizes.

WPF Units

A WPF window and all the elements inside it are measured using device-independent units. A single device-independent unit is defined as 1/96 of an inch. To understand what this means in practice, you’ll need to consider an example.

Imagine that you create a small button in WPF that’s 96 by 96 units in size. If you’re using the standard Windows DPI setting (96 dpi), each device-independent unit corresponds to one real, physical pixel. That’s because WPF uses this calculation:

[Physical Unit Size] = [Device-Independent Unit Size] × [System DPI]

                 = 1/96 inch × 96 dpi

                 = 1 pixel

Essentially, WPF assumes it takes 96 pixels to make an inch because Windows tells it that through the system DPI setting. However, the reality depends on your display device.

For example, consider a 20-inch LCD monitor with a maximum resolution of 1600 by 1200 pixels. Using a dash of Pythagoras, you can calculate the pixel density for this monitor, as shown here:

[Screen DPI] = ((Sqroot of)(1600*1600)+(1200*1200))pixels/19 inches = 100dpi

In this case, the pixel density works out to 100 dpi, which is slightly higher than what Windows assumes. As a result, on this monitor a 96-by-96-pixel button will be slightly smaller than 1 inch.

On the other hand, consider a 15-inch LCD monitor with a resolution of 1024 by 768. Here, the pixel density drops to about 85 dpi, so the 96-by-96 pixel button appears slightly larger than 1 inch.

In both these cases, if you reduce the screen size (say, by switching to 800 by 600 resolution), the button (and every other screen element) will appear proportionately larger. That’s because the system DPI setting remains at 96 dpi. In other words, Windows continues to assume it takes 96 pixels to make an inch, even though at a lower resolution it takes far fewer pixels.

Reference: Pro WPF in C# 2008: Windows Presentation Foundation with .NET 3.5, Second Edition

WPF uses device-independent coordinates which means applications scale correctly and uniformly at different DPI settings.

Another very useful feature of WPF is the ViewBox which can be used to create a scalable application. Try the following.

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Width="300" Height="300">
    <Viewbox Stretch="Uniform">
        <Grid Width="300" Height="300">
            <Button Content="Button" Margin="16,8,0,0" 
                    Width="104" Height="32" 
                    HorizontalAlignment="Left" 
                    VerticalAlignment="Top" />
            <CheckBox Content="CheckBox" Margin="136,8,0,0" 
                      Width="112" Height="24" 
                      HorizontalAlignment="Left" VerticalAlignment="Top" />
        </Grid>
    </Viewbox>
</Window>

This simple example is a little off cause of the window title bar and border but you get the idea. When this window is resized, the content scales uniformly so it looks the same at any resolution.

You can use WPF for your application. Every control that you create on a form will be the in different screen resolutions.

One of the main claimed benefits of WPF is “resolution independence”. Often this benefit is described in relatively vague terms leading people to believe that it means that the same WPF window will display on any monitor at the same size regardless of the resolution at which that monitor is set.

I think it means that the proportions should be the same, on different resolutions. It doesn't mean the application will resize its windows internally to adjust to the new resolution. But this is not universal.

Another very important thing to mention, is the context this is brought on. For example there are different expectations for a web application, which may change the layout or page size depending on the resolution. Video games, which may render things very differently depending on the screen resolution and aspect. And regular windows applications (GUI), which I already mentioned.