R – WPF – Databind slider value to StoryBoard

animationdata-bindingexpression-blendstoryboardwpf

I'm trying to create a sound volume control and for that I've created a storyboard which is animating the volume visually. And I've put this inside an common slider control. And I want to databind the value of the slider directly to the storyboards timeline position. If the slider is value 0, then the storyboard should be at 00:00 etc, all th way up to the top. Is this possible?

This is the code of the control. The Storyboard animation is in here.

<ControlTemplate TargetType="{x:Type Slider}">
                    <ControlTemplate.Resources>
                        <Storyboard x:Key="SoundControl_Animation">
                            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="path3" Storyboard.TargetProperty="(UIElement.Opacity)">
                                <SplineDoubleKeyFrame KeyTime="00:00:00" Value="0.005"/>
                                <SplineDoubleKeyFrame KeyTime="00:00:00.5000000" Value="0"/>
                                <SplineDoubleKeyFrame KeyTime="00:00:01" Value="1"/>
                            </DoubleAnimationUsingKeyFrames>
                            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="path2" Storyboard.TargetProperty="(UIElement.Opacity)">
                                <SplineDoubleKeyFrame KeyTime="00:00:00" Value="0"/>
                                <SplineDoubleKeyFrame KeyTime="00:00:00.5000000" Value="1"/>
                            </DoubleAnimationUsingKeyFrames>
                            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="path1" Storyboard.TargetProperty="(UIElement.Opacity)">
                                <SplineDoubleKeyFrame KeyTime="00:00:00" Value="0.495"/>
                                <SplineDoubleKeyFrame KeyTime="00:00:00.5000000" Value="1"/>
                            </DoubleAnimationUsingKeyFrames>
                        </Storyboard>
                    </ControlTemplate.Resources>
                    <Grid Width="Auto" Height="Auto">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="51.333"/>
                            <ColumnDefinition Width="*"/>
                        </Grid.ColumnDefinitions>
                        <Grid x:Name="GridRoot" Margin="0,0,0,0" Grid.Column="1" HorizontalAlignment="Stretch" VerticalAlignment="Center">
                            <Grid.RowDefinitions>
                                <RowDefinition Height="Auto"/>
                                <RowDefinition Height="Auto" MinHeight="{TemplateBinding MinHeight}"/>
                                <RowDefinition Height="Auto"/>
                            </Grid.RowDefinitions>

                            <!-- TickBar shows the ticks for Slider -->
                            <TickBar Visibility="Collapsed" x:Name="TopTick" Height="4" SnapsToDevicePixels="True" Placement="Top" Fill="{DynamicResource GlyphBrush}"/>
                            <Border Grid.Row="1" Margin="0" x:Name="Border" Height="4" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="2"/>

                            <!-- The Track lays out the repeat buttons and thumb -->
                            <Track Grid.Row="1" x:Name="PART_Track">
                                <Track.Thumb>
                                    <Thumb Style="{DynamicResource SimpleSliderThumb}"/>
                                </Track.Thumb>
                                <Track.IncreaseRepeatButton>
                                    <RepeatButton Style="{DynamicResource SimpleScrollRepeatButtonStyle}" Command="Slider.IncreaseLarge"/>
                                </Track.IncreaseRepeatButton>
                                <Track.DecreaseRepeatButton>
                                    <RepeatButton Style="{DynamicResource SimpleScrollRepeatButtonStyle}" Command="Slider.DecreaseLarge"/>
                                </Track.DecreaseRepeatButton>
                            </Track>

                            <TickBar Visibility="Collapsed" Grid.Row="2" x:Name="BottomTick" Height="4" SnapsToDevicePixels="True" Placement="Bottom" Fill="{TemplateBinding Foreground}"/>
                        </Grid>
                        <Path Stretch="Fill" Data="F1 M-65.067448,318.22277 C-65.067448,318.22277 -58.87652,318.2416 -58.87652,318.2416 -58.797256,318.31822 -54.599352,312.8803 -54.599352,312.8803 -54.599352,312.8803 -54.601205,330.97579 -54.601205,330.97579 -54.601205,330.97579 -58.83846,325.45217 -58.83846,325.45217 -58.83846,325.45217 -64.980101,325.3728 -64.988066,325.38226 -65.018879,325.41884 -65.067448,318.22277 -65.067448,318.22277 z" HorizontalAlignment="Left" Margin="0,0,0,0" Stroke="{DynamicResource DrawBrush_IconStroke}" StrokeThickness="1" Fill="{DynamicResource DrawBrush_Std_Button_HighlightPatch_MouseOver}" x:Name="path" Width="15" Opacity="1" VerticalAlignment="Stretch" Grid.Column="0" Height="20"/>
                        <Path Margin="20.671,14,26.662,14" Fill="{x:Null}" Stretch="Fill" StrokeThickness="2" Data="M75.569117,15.851553 C75.569117,15.851553 85.628643,23.181896 75.250364,31.167364" HorizontalAlignment="Stretch" Width="4" Grid.Column="0" Height="10" Stroke="#FF666666" d:LayoutOverrides="HorizontalAlignment" x:Name="path1"/>
                        <Path Margin="25.51,9,19.823,9" Fill="{x:Null}" Stretch="Fill" StrokeThickness="2.5" Data="M75.569117,15.851553 C75.569117,15.851553 85.628643,23.181896 75.250364,31.167364" HorizontalAlignment="Stretch" Height="20" Stroke="#FF848484" x:Name="path2"/>
                        <Path Margin="0,4,12.156,4" Fill="{x:Null}" Stretch="Fill" StrokeThickness="3" Data="M75.569117,15.851553 C75.569117,15.851553 85.628643,23.181896 75.250364,31.167364" HorizontalAlignment="Right" Width="8" Height="30" Stroke="#FFB9B9B9" x:Name="path3"/>
                    </Grid>
                    <ControlTemplate.Triggers>
                        <Trigger Property="TickPlacement" Value="TopLeft">
                            <Setter Property="Visibility" Value="Visible" TargetName="TopTick"/>
                        </Trigger>
                        <Trigger Property="TickPlacement" Value="BottomRight">
                            <Setter Property="Visibility" Value="Visible" TargetName="BottomTick"/>
                        </Trigger>
                        <Trigger Property="TickPlacement" Value="Both">
                            <Setter Property="Visibility" Value="Visible" TargetName="TopTick"/>
                            <Setter Property="Visibility" Value="Visible" TargetName="BottomTick"/>
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Background" Value="{DynamicResource DisabledBackgroundBrush}" TargetName="Border"/>
                            <Setter Property="BorderBrush" Value="{DynamicResource DisabledBorderBrush}" TargetName="Border"/>
                        </Trigger>

                        <!-- Use a rotation to create a Vertical Slider form the default Horizontal -->
                        <Trigger Property="Orientation" Value="Vertical">
                            <Setter Property="LayoutTransform" TargetName="GridRoot">
                                <Setter.Value>
                                    <RotateTransform Angle="-90"/>
                                </Setter.Value>
                            </Setter>
                            <!-- Track rotates itself based on orientation so need to force it back -->
                            <Setter TargetName="PART_Track" Property="Orientation" Value="Horizontal"/>
                        </Trigger>

                    </ControlTemplate.Triggers>
                </ControlTemplate>

And the control itself it put on the Canvas like this:

<Slider Margin="47.75,9.75,0,0" Style="{DynamicResource btn_SoundVolumeSlider}" Grid.Column="3" d:LayoutOverrides="Height" VerticalAlignment="Top" HorizontalAlignment="Stretch" SmallChange="0" TickFrequency="0" Value="3"/>

Best Answer

It depends on what you plan to achieve. The point is that property binding should be performed across items on the visual tree. If you show the animation I can tell how is the proper way to bind the animation and the slider value.

For example, if your animation is a turning knob the way to do it is binding the slider value through a converter to the rotation angle of the item you want to animate. But, as I said, it depends on your animation. Show it, even a JPEG, and I can tell more details.

UPDATE

As of 8/1/2014, the article I linked to above is still active, but the blog hasn't been updated in a while. That makes me worry that eventually it might disappear, and with it, the advocated solution. I'm reproducing the content of the article here for posterity. The words belong solely to the blog owner at Sanity Free Coding.

Today I wanted to refactor some code that prohibited my application from running multiple instances of itself.

Previously I had use System.Diagnostics.Process to search for an instance of my myapp.exe in the process list. While this works, it brings on a lot of overhead, and I wanted something cleaner.

Knowing that I could use a mutex for this (but never having done it before) I set out to cut down my code and simplify my life.

In the class of my application main I created a static named Mutex:

static class Program
{
    static Mutex mutex = new Mutex(true, "{8F6F0AC4-B9A1-45fd-A8CF-72F04E6BDE8F}");
    [STAThread]
    ...
}

Having a named mutex allows us to stack synchronization across multiple threads and processes which is just the magic I'm looking for.

Mutex.WaitOne has an overload that specifies an amount of time for us to wait. Since we're not actually wanting to synchronizing our code (more just check if it is currently in use) we use the overload with two parameters: Mutex.WaitOne(Timespan timeout, bool exitContext). Wait one returns true if it is able to enter, and false if it wasn't. In this case, we don't want to wait at all; If our mutex is being used, skip it, and move on, so we pass in TimeSpan.Zero (wait 0 milliseconds), and set the exitContext to true so we can exit the synchronization context before we try to aquire a lock on it. Using this, we wrap our Application.Run code inside something like this:

static class Program
{
    static Mutex mutex = new Mutex(true, "{8F6F0AC4-B9A1-45fd-A8CF-72F04E6BDE8F}");
    [STAThread]
    static void Main() {
        if(mutex.WaitOne(TimeSpan.Zero, true)) {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
            mutex.ReleaseMutex();
        } else {
            MessageBox.Show("only one instance at a time");
        }
    }
}

So, if our app is running, WaitOne will return false, and we'll get a message box.

Instead of showing a message box, I opted to utilize a little Win32 to notify my running instance that someone forgot that it was already running (by bringing itself to the top of all the other windows). To achieve this I used PostMessage to broadcast a custom message to every window (the custom message was registered with RegisterWindowMessage by my running application, which means only my application knows what it is) then my second instance exits. The running application instance would receive that notification and process it. In order to do that, I overrode WndProc in my main form and listened for my custom notification. When I received that notification I set the form's TopMost property to true to bring it up on top.

Here is what I ended up with:

Program.cs

static class Program
{
    static Mutex mutex = new Mutex(true, "{8F6F0AC4-B9A1-45fd-A8CF-72F04E6BDE8F}");
    [STAThread]
    static void Main() {
        if(mutex.WaitOne(TimeSpan.Zero, true)) {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
            mutex.ReleaseMutex();
        } else {
            // send our Win32 message to make the currently running instance
            // jump on top of all the other windows
            NativeMethods.PostMessage(
                (IntPtr)NativeMethods.HWND_BROADCAST,
                NativeMethods.WM_SHOWME,
                IntPtr.Zero,
                IntPtr.Zero);
        }
    }
}

NativeMethods.cs

// this class just wraps some Win32 stuff that we're going to use
internal class NativeMethods
{
    public const int HWND_BROADCAST = 0xffff;
    public static readonly int WM_SHOWME = RegisterWindowMessage("WM_SHOWME");
    [DllImport("user32")]
    public static extern bool PostMessage(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam);
    [DllImport("user32")]
    public static extern int RegisterWindowMessage(string message);
}

Form1.cs (front side partial)

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    protected override void WndProc(ref Message m)
    {
        if(m.Msg == NativeMethods.WM_SHOWME) {
            ShowMe();
        }
        base.WndProc(ref m);
    }
    private void ShowMe()
    {
        if(WindowState == FormWindowState.Minimized) {
            WindowState = FormWindowState.Normal;
        }
        // get our current "TopMost" value (ours will always be false though)
        bool top = TopMost;
        // make our form jump to the top of everything
        TopMost = true;
        // set it back to whatever it was
        TopMost = top;
    }
}

WPF Databind Before Saving

I found that removing the menu items that are scope depended from the FocusScope of the menu causes the textbox to lose focus correctly. I wouldn't think this applies to ALL items in Menu, but certainly for a save or validate action.

<Menu FocusManager.IsFocusScope="False" >

Best Answer

Related Solutions

C# – the correct way to create a single-instance WPF application

UPDATE

WPF Databind Before Saving

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