---
lang: ja-jp
breaks: true
---
# WPF ウィンドウ内のコンテンツをマウスホイールでズームする機能　2021-04-28

> UI Scaling (UI Zooming) with WPF
> https://docs.microsoft.com/ja-jp/archive/blogs/ivo_manolov/ui-scaling-ui-zooming-with-wpf
> https://msdnshared.blob.core.windows.net/media/MSDNBlogsFS/prod.evol.blogs.msdn.com/CommunityServer.Components.PostAttachments/00/05/29/93/62/ScalableUI.zip

～・・・～
        <DockPanel Grid.Column="0" Grid.ColumnSpan="2" LastChildFill="True">
            <DockPanel.LayoutTransform>
                <ScaleTransform
                    CenterX="0" CenterY="0"
                    ScaleX="{Binding ElementName=uiScaleSlider,Path=Value}"
                    ScaleY="{Binding ElementName=uiScaleSlider,Path=Value}"
                />
            </DockPanel.LayoutTransform>
～・・・～
        </DockPanel>

        <Slider
            x:Name="uiScaleSlider"
            Grid.Column="1"
            HorizontalAlignment="Center"
            VerticalAlignment="Bottom"
            ToolTip="Determines the UI scale factor. Double-click to revert scaling back to 100%."
            Height="100"
            Value="1" Minimum="0.1" Maximum="10.0"
            Orientation="Vertical"
            Ticks="1"
            IsSnapToTickEnabled="False"
            TickPlacement="BottomRight"
            AutoToolTipPlacement="BottomRight"
            AutoToolTipPrecision="2"
        />

        /// <summary>
        /// The user can scale up/down the UI by using the mouse wheel while holding down
        /// the Ctrl key.
        /// </summary>
        protected override void OnPreviewMouseWheel(MouseWheelEventArgs args)
        {
            base.OnPreviewMouseWheel(args);
            if (Keyboard.IsKeyDown(Key.LeftCtrl) || Keyboard.IsKeyDown(Key.RightCtrl))
            {
                uiScaleSlider.Value += (args.Delta > 0) ? 0.1 : -0.1;
            }
        }


###### tags: `WPF` `ScalableUI` `DockPanel` `ScaleTransform` `XAML`