what is the best way to display a 'loading' indicator on a WPF control

Question

In C#.Net WPF During UserControl.Load ->

What is the best way of showing a whirling circle / 'Loading' Indicator on the UserControl until it has finished gathering data and rendering it's contents?

Answer 1

I generally would create a layout like this:

<Grid>
    <Grid x:Name="MainContent" IsEnabled="False">
    ...
    </Grid>

    <Grid x:Name="LoadingIndicatorPanel">
    ...
    </Grid>
</Grid>

Then I load the data on a worker thread, and when it's finished I update the UI under the "MainContent" grid and enable the grid, then set the LoadingIndicatorPanel's Visibility to Collapsed.

I'm not sure if this is what you were asking or if you wanted to know how to show an animation in the loading label. If it's the animation you're after, please update your question to be more specific.

Answer 2

This is something that I was working on just recently in order to create a loading animation. This xaml will produce an animated ring of circles.

My initial idea was to create an adorner and use this animation as it's content, then to display the loading animation in the adorners layer and grey out the content underneath.

Haven't had the chance to finish it yet, so I thought I would just post the animation for your reference.

<Window 
    x:Class="WpfApplication2.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1"
    Height="300"
    Width="300"
    >
    <Window.Resources>
        <Color x:Key="FilledColor" A="255" B="155" R="155" G="155"/>
        <Color x:Key="UnfilledColor" A="0" B="155" R="155" G="155"/>

        <Storyboard x:Key="Animation0" FillBehavior="Stop" BeginTime="00:00:00.0" RepeatBehavior="Forever">
            <ColorAnimationUsingKeyFrames Storyboard.TargetName="_00" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)">
                <SplineColorKeyFrame KeyTime="00:00:00.0" Value="{StaticResource FilledColor}"/>
                <SplineColorKeyFrame KeyTime="00:00:01.6" Value="{StaticResource UnfilledColor}"/>
            </ColorAnimationUsingKeyFrames>
        </Storyboard>

        <Storyboard x:Key="Animation1" BeginTime="00:00:00.2" RepeatBehavior="Forever">
            <ColorAnimationUsingKeyFrames Storyboard.TargetName="_01" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)">
                <SplineColorKeyFrame KeyTime="00:00:00.0" Value="{StaticResource FilledColor}"/>
                <SplineColorKeyFrame KeyTime="00:00:01.6" Value="{StaticResource UnfilledColor}"/>
            </ColorAnimationUsingKeyFrames>
        </Storyboard>

        <Storyboard x:Key="Animation2" BeginTime="00:00:00.4" RepeatBehavior="Forever">
            <ColorAnimationUsingKeyFrames Storyboard.TargetName="_02" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)">
                <SplineColorKeyFrame KeyTime="00:00:00.0" Value="{StaticResource FilledColor}"/>
                <SplineColorKeyFrame KeyTime="00:00:01.6" Value="{StaticResource UnfilledColor}"/>
            </ColorAnimationUsingKeyFrames>
        </Storyboard>

        <Storyboard x:Key="Animation3" BeginTime="00:00:00.6" RepeatBehavior="Forever">
            <ColorAnimationUsingKeyFrames Storyboard.TargetName="_03" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)">
                <SplineColorKeyFrame KeyTime="00:00:00.0" Value="{StaticResource FilledColor}"/>
                <SplineColorKeyFrame KeyTime="00:00:01.6" Value="{StaticResource UnfilledColor}"/>
            </ColorAnimationUsingKeyFrames>
        </Storyboard>

        <Storyboard x:Key="Animation4" BeginTime="00:00:00.8" RepeatBehavior="Forever">
            <ColorAnimationUsingKeyFrames Storyboard.TargetName="_04" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)">
                <SplineColorKeyFrame KeyTime="00:00:00.0" Value="{StaticResource FilledColor}"/>
                <SplineColorKeyFrame KeyTime="00:00:01.6" Value="{StaticResource UnfilledColor}"/>
            </ColorAnimationUsingKeyFrames>
        </Storyboard>

        <Storyboard x:Key="Animation5" BeginTime="00:00:01.0" RepeatBehavior="Forever">
            <ColorAnimationUsingKeyFrames Storyboard.TargetName="_05" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)">
                <SplineColorKeyFrame KeyTime="00:00:00.0" Value="{StaticResource FilledColor}"/>
                <SplineColorKeyFrame KeyTime="00:00:01.6" Value="{StaticResource UnfilledColor}"/>
            </ColorAnimationUsingKeyFrames>
        </Storyboard>

        <Storyboard x:Key="Animation6" BeginTime="00:00:01.2" RepeatBehavior="Forever">
            <ColorAnimationUsingKeyFrames Storyboard.TargetName="_06" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)">
                <SplineColorKeyFrame KeyTime="00:00:00.0" Value="{StaticResource FilledColor}"/>
                <SplineColorKeyFrame KeyTime="00:00:01.6" Value="{StaticResource UnfilledColor}"/>
            </ColorAnimationUsingKeyFrames>
        </Storyboard>

        <Storyboard x:Key="Animation7" BeginTime="00:00:01.4" RepeatBehavior="Forever">
            <ColorAnimationUsingKeyFrames Storyboard.TargetName="_07" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)">
                <SplineColorKeyFrame KeyTime="00:00:00.0" Value="{StaticResource FilledColor}"/>
                <SplineColorKeyFrame KeyTime="00:00:01.6" Value="{StaticResource UnfilledColor}"/>
            </ColorAnimationUsingKeyFrames>
        </Storyboard>
    </Window.Resources>

    <Window.Triggers>
     <EventTrigger RoutedEvent="FrameworkElement.Loaded">
      <BeginStoryboard Storyboard="{StaticResource Animation0}"/>
      <BeginStoryboard Storyboard="{StaticResource Animation1}"/>
      <BeginStoryboard Storyboard="{StaticResource Animation2}"/>
      <BeginStoryboard Storyboard="{StaticResource Animation3}"/>
      <BeginStoryboard Storyboard="{StaticResource Animation4}"/>
      <BeginStoryboard Storyboard="{StaticResource Animation5}"/>
      <BeginStoryboard Storyboard="{StaticResource Animation6}"/>
      <BeginStoryboard Storyboard="{StaticResource Animation7}"/>
     </EventTrigger>
    </Window.Triggers>

    <Canvas>
        <Canvas Canvas.Left="21.75" Canvas.Top="14" Height="81.302" Width="80.197">
            <Canvas.Resources>
                <Style TargetType="Ellipse">
                    <Setter Property="Width" Value="15"/>
                    <Setter Property="Height" Value="15" />
                    <Setter Property="Fill" Value="#FFFFFFFF" />
                </Style>
            </Canvas.Resources>

            <Ellipse x:Name="_00" Canvas.Left="24.75" Canvas.Top="50"/>
            <Ellipse x:Name="_01" Canvas.Top="36" Canvas.Left="29.5"/>
            <Ellipse x:Name="_02" Canvas.Left="43.5" Canvas.Top="29.75"/>
            <Ellipse x:Name="_03" Canvas.Left="57.75" Canvas.Top="35.75"/>
            <Ellipse x:Name="_04" Canvas.Left="63.5" Canvas.Top="49.75" />
            <Ellipse x:Name="_05" Canvas.Left="57.75" Canvas.Top="63.5"/>
            <Ellipse x:Name="_06" Canvas.Left="43.75" Canvas.Top="68.75"/>
            <Ellipse x:Name="_07" Canvas.Top="63.25" Canvas.Left="30" />
            <Ellipse Stroke="{x:Null}" Width="39.5" Height="39.5" Canvas.Left="31.75" Canvas.Top="37" Fill="{x:Null}"/>
        </Canvas>
    </Canvas>
</Window>

Answer 3

If you are running it on Vista, you could also just use the default wait cursor.

this.Cursor = Cursors.Wait;

Answer 4

Use BusyIndicator. It's a silverlight thing.

Answer 5

You can show animated gif as loading element

XAML

<WindowsFormsHost>
    <winForms:PictureBox x:Name="pictureBoxLoading" />
</WindowsFormsHost>

CODE BEHIND

pictureBoxLoading.Image = System.Drawing.Image.FromFile("images/ajax-loader.gif");