[C#/WINUI3/.NET6] ScrollView 엘리먼트 : AddScrollVelocity 메소드를 사용해 등속 스크롤 처리하기

■ ScrollView 엘리먼트의 AddScrollVelocity 메소드를 사용해 등속 스크롤을 처리하는 방법을 보여준다.

▶ MainPage.xaml


<?xml version="1.0" encoding="utf-8"?>
<Page x:Class="TestProject.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
    FontFamily="나눔고딕코딩"
    FontSize="16">
    <Grid Margin="10">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"    />
            <ColumnDefinition Width="10"   />
            <ColumnDefinition Width="Auto" />
        </Grid.ColumnDefinitions>
        <ScrollView Name="scrollView" Grid.Column="0"
            HorizontalAlignment="Center"
            VerticalAlignment="Center"
            Width="400"
            Height="300"
            IsTabStop="True">
            <StackPanel>
                <Image Source="ms-appx:///IMAGE/grapes.jpg"   Stretch="Uniform" />
                <Image Source="ms-appx:///IMAGE/rainier.jpg"  Stretch="Uniform" />
                <Image Source="ms-appx:///IMAGE/sunset.jpg"   Stretch="Uniform" />
                <Image Source="ms-appx:///IMAGE/treetops.jpg" Stretch="Uniform" />
                <Image Source="ms-appx:///IMAGE/valley.jpg"   Stretch="Uniform" />
                <Image Source="ms-appx:///IMAGE/cliff.jpg"    Stretch="Uniform" />
            </StackPanel>
        </ScrollView>
        <Grid Grid.Column="2"
            HorizontalAlignment="Center"
            VerticalAlignment="Center"
            RowDefinitions="Auto"
            ColumnDefinitions="Auto,*">
            <TextBlock Grid.Row="0" Grid.Column="0"
                VerticalAlignment="Center"
                Text="Vertical velocity" />
            <NumberBox Name="verticalVelocityNumberBox" Grid.Row="0" Grid.Column="1"
                Margin="10 0 0 0"
                Minimum="-200"
                Maximum="200"
                Value="30"
                SpinButtonPlacementMode="Inline"
                SmallChange="10"
                LargeChange="30"
                VerticalContentAlignment="Center">
            </NumberBox>
        </Grid>
    </Grid>
</Page>

<?xml version="1.0" encoding="utf-8"?>

<Page x:Class="TestProject.MainPage"

xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"

FontFamily="나눔고딕코딩"

FontSize="16">

<Grid.ColumnDefinitions>

</Grid.ColumnDefinitions>

<ScrollView Name="scrollView" Grid.Column="0"

HorizontalAlignment="Center"

VerticalAlignment="Center"

Width="400"

Height="300"

IsTabStop="True">

</StackPanel>

</ScrollView>

<Grid Grid.Column="2"

HorizontalAlignment="Center"

VerticalAlignment="Center"

RowDefinitions="Auto"

ColumnDefinitions="Auto,*">

<TextBlock Grid.Row="0" Grid.Column="0"

VerticalAlignment="Center"

Text="Vertical velocity" />

<NumberBox Name="verticalVelocityNumberBox" Grid.Row="0" Grid.Column="1"

Margin="10 0 0 0"

Minimum="-200"

Maximum="200"

Value="30"

SpinButtonPlacementMode="Inline"

SmallChange="10"

LargeChange="30"

VerticalContentAlignment="Center">

</NumberBox>

</Grid>

</Page>

▶ MainPage.xaml.cs


using System.Numerics;

using Microsoft.UI.Xaml.Controls;

namespace TestProject
{
    /// <summary>
    /// 메인 페이지
    /// </summary>
    public sealed partial class MainPage : Page
    {
        //////////////////////////////////////////////////////////////////////////////////////////////////// Constructor
        ////////////////////////////////////////////////////////////////////////////////////////// Public

        #region 생성자 - MainPage()

        /// <summary>
        /// 생성자
        /// </summary>
        public MainPage()
        {
            InitializeComponent();

            this.verticalVelocityNumberBox.ValueChanged += verticalVelocityNumberBox_ValueChanged;
        }

        #endregion

        //////////////////////////////////////////////////////////////////////////////////////////////////// Method
        ////////////////////////////////////////////////////////////////////////////////////////// Private

        #region Vertical Velocity 넘버 박스 값 변경시 처리하기 - verticalVelocityNumberBox_ValueChanged(sender, e)

        /// <summary>
        /// Vertical Velocity 넘버 박스 값 변경시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void verticalVelocityNumberBox_ValueChanged(NumberBox sender, NumberBoxValueChangedEventArgs e)
        {
            if(double.IsNaN(e.OldValue))
            {
                return;
            }

            if(this.scrollView != null)
            {
                this.scrollView.ScrollBy
                (
                    0,
                    0,
                    new ScrollingScrollOptions(ScrollingAnimationMode.Disabled, ScrollingSnapPointsMode.Ignore)
                );

                float verticalConstantVelocity = (float)this.verticalVelocityNumberBox.Value;

                if(e.NewValue <= 30.0 && e.NewValue >= -30)
                {
                    if(e.NewValue < e.OldValue)
                    {
                        if(this.scrollView.VerticalOffset == 0)
                        {
                            verticalConstantVelocity = 30;
                        }
                        else
                        {
                            verticalConstantVelocity = -30;
                        }
                    }
                    else
                    {
                        if(this.scrollView.VerticalOffset == this.scrollView.ScrollableHeight)
                        {
                            verticalConstantVelocity = -30;
                        }
                        else
                        {
                            verticalConstantVelocity = 30;
                        }
                    }
                }
                else if(e.NewValue < 30.0 && this.scrollView.VerticalOffset == 0)
                {
                    verticalConstantVelocity = 30;
                }
                else if (e.NewValue > 30.0 && this.scrollView.VerticalOffset == this.scrollView.ScrollableHeight)
                {
                    verticalConstantVelocity = -30;
                }

                this.verticalVelocityNumberBox.Value = verticalConstantVelocity;

                this.scrollView.AddScrollVelocity
                (
                    new Vector2(0f, verticalConstantVelocity),
                    new Vector2()
                );
            }
        }

        #endregion
    }
}

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using System.Numerics;

using Microsoft.UI.Xaml.Controls;

namespace TestProject

{

/// <summary>

/// 메인 페이지

/// </summary>

public sealed partial class MainPage : Page

{

//////////////////////////////////////////////////////////////////////////////////////////////////// Constructor

////////////////////////////////////////////////////////////////////////////////////////// Public

#region 생성자 - MainPage()

/// <summary>

/// 생성자

/// </summary>

public MainPage()

{

InitializeComponent();

this.verticalVelocityNumberBox.ValueChanged += verticalVelocityNumberBox_ValueChanged;

}

#endregion

//////////////////////////////////////////////////////////////////////////////////////////////////// Method

////////////////////////////////////////////////////////////////////////////////////////// Private

#region Vertical Velocity 넘버 박스 값 변경시 처리하기 - verticalVelocityNumberBox_ValueChanged(sender, e)

/// <summary>

/// Vertical Velocity 넘버 박스 값 변경시 처리하기

/// </summary>

/// <param name="sender">이벤트 발생자</param>

/// <param name="e">이벤트 인자</param>

private void verticalVelocityNumberBox_ValueChanged(NumberBox sender, NumberBoxValueChangedEventArgs e)

{

if(double.IsNaN(e.OldValue))

{

return;

}

if(this.scrollView != null)

{

this.scrollView.ScrollBy

(

new ScrollingScrollOptions(ScrollingAnimationMode.Disabled, ScrollingSnapPointsMode.Ignore)

);

float verticalConstantVelocity = (float)this.verticalVelocityNumberBox.Value;

if(e.NewValue <= 30.0 && e.NewValue >= -30)

{

if(e.NewValue < e.OldValue)

{

if(this.scrollView.VerticalOffset == 0)

{

verticalConstantVelocity = 30;

}

else

{

verticalConstantVelocity = -30;

}

else

{

if(this.scrollView.VerticalOffset == this.scrollView.ScrollableHeight)

{

verticalConstantVelocity = -30;

}

else

{

verticalConstantVelocity = 30;

}

else if(e.NewValue < 30.0 && this.scrollView.VerticalOffset == 0)

{

verticalConstantVelocity = 30;

}

else if (e.NewValue > 30.0 && this.scrollView.VerticalOffset == this.scrollView.ScrollableHeight)

{

verticalConstantVelocity = -30;

}

this.verticalVelocityNumberBox.Value = verticalConstantVelocity;

this.scrollView.AddScrollVelocity

(

new Vector2(0f, verticalConstantVelocity),

new Vector2()

);

}

#endregion

}

TestProject.zip