我使用WIN2D在画布上绘制了一些弧线。要在画布图像中实现平移和捏合，我使用了下面的代码...
XAML
</Canvas>-->
<ScrollViewer x:Name="scrollViewer"
VerticalScrollBarVisibility="Auto"
HorizontalScrollBarVisibility="Auto"
Margin="-0,0,0,0"
Height="806"
ZoomMode="Enabled"
MinZoomFactor="0.5"
MaxZoomFactor="8000"
ViewChanged="scrollViewer_ViewChanged">
<Grid Margin="-10,0,0,0">
<canvas:CanvasControl x:Name="ManipulateMe"
Draw="Preview_Draw"
Margin="-11,1,0,0"
IsDoubleTapEnabled="True"
IsTapEnabled="True"
DoubleTapped="Preview_DoubleTapped"
Height="855"
Width="427.5">
</canvas:CanvasControl>
</Grid>
</ScrollViewer>
<!--</controls:ManipulationContentControl>-->
</Canvas>
.CS
private void Preview_Draw（Microsoft.Graphics.Canvas.UI.Xaml.CanvasControl发送者，Microsoft.Graphics.Canvas.UI.Xaml.CanvasDrawEventArgs args） {试试
{
string GCodefile = ((ltvSelectExecution).SelectedItem as FolderFilesInfo).Name + ((ltvSelectExecution).SelectedItem as FolderFilesInfo).Extension;
var EntityArcLines = execution.GetArcLinesParams(GCodefile, null, false);
var pathGeometric = execution.GetPathGeometry(EntityArcLines);
int flag;
CanvasPathBuilder pathBuilder = new CanvasPathBuilder(ManipulateMe.Device);
pathGeometric.ForEach(t =>
{
Vector2 finalPoints = new Vector2()
{
X = (float)t.Xf,
Y = (float)t.Yf
};
float r = (float)Math.Sqrt(Math.Pow(t.I, 2) + Math.Pow(t.J, 2));
float x = 7;
float y = 7;
var clockwise = t.DirectionRotate;
CanvasSweepDirection canvasSweepDirection = clockwise == 0 ? CanvasSweepDirection.CounterClockwise : CanvasSweepDirection.Clockwise;
flag = t.G == 0 ? 0 : 1;
if (t.I != 0 || t.J != 0)
{
pathBuilder.BeginFigure((float)t.Xi, (float)t.Yi);
pathBuilder.AddArc(finalPoints, x, y, (float)0, canvasSweepDirection, CanvasArcSize.Small);
pathBuilder.EndFigure(CanvasFigureLoop.Open);
}
else
{
pathBuilder.BeginFigure((float)t.Xi, (float)t.Yi);
pathBuilder.AddLine(finalPoints);
pathBuilder.EndFigure(CanvasFigureLoop.Open);
}
});
CanvasGeometry triangleGeometry = CanvasGeometry.CreatePath(pathBuilder);
using (var drawSession = args.DrawingSession)
{
//Vector2 vectorScale = new Vector2()
//{
// X = (float)_compositeTransform.ScaleX,
// Y = (float)_compositeTransform.ScaleY
//};
//ScaleEffect scaleEffect = new ScaleEffect()
//{
// Scale = vectorScale
//};
drawSession.DrawGeometry(triangleGeometry, Colors.White, (float)1);
//};
}
}
catch (Exception ex)
{
var teste = 0;
};
}
private void Page_Loaded(object sender, RoutedEventArgs e)
{
// Initialize the display DPI, and listen for events in case this changes.
var display = DisplayInformation.GetForCurrentView();
display.DpiChanged += Display_DpiChanged;
Display_DpiChanged(display, null);
// Initialize the help text depending on what input devices are available.
var toZoom = new List<string>();
if (new TouchCapabilities().TouchPresent > 0)
{
toZoom.Add("Pinch");
}
if (new KeyboardCapabilities().KeyboardPresent > 0)
{
toZoom.Add("A/Z");
if (new MouseCapabilities().VerticalWheelPresent > 0)
{
toZoom.Add("Ctrl+Wheel");
}
}
//helpText.Text = "To zoom:\n " + string.Join("\n ", toZoom);
// Set focus to our control, so it will receive keyboard input.
ManipulateMe.Focus(FocusState.Programmatic);
}
private void Page_Unloaded(object sender, RoutedEventArgs e)
{
// Explicitly remove references to allow the Win2D controls to get garbage collected
ManipulateMe.RemoveFromVisualTree();
ManipulateMe = null;
DisplayInformation.GetForCurrentView().DpiChanged -= Display_DpiChanged;
}
void Display_DpiChanged(DisplayInformation sender, object args)
{
displayDpi = sender.LogicalDpi;
// Manually call the ViewChanged handler to update DpiScale.
scrollViewer_ViewChanged(null, null);
}
private void scrollViewer_ViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
{
// Cancel out the display DPI, so our fractal always renders at 96 DPI regardless of display
// configuration. This boosts performance on high DPI displays, at the cost of visual quality.
// For even better performance (but lower quality) this value could be further reduced.
float dpiAdjustment = 96 / displayDpi;
// Adjust DPI to match the current zoom level.
float dpiScale = dpiAdjustment * scrollViewer.ZoomFactor;
// To boost performance during pinch-zoom manipulations, we only update DPI when it has
// changed by more than 20%, or at the end of the zoom (when e.IsIntermediate reports false).
// Smaller changes will just scale the existing bitmap, which is much faster than recomputing
// the fractal at a different resolution. To trade off between zooming perf vs. smoothness,
// adjust the thresholds used in this ratio comparison.
var ratio = ManipulateMe.DpiScale / dpiScale;
if (e == null || !e.IsIntermediate || ratio <= 0.8 || ratio >= 1.25)
{
ManipulateMe.DpiScale = dpiScale;
}
}
我希望图像以与屏幕相同的宽度从中心开始。
我的照片开始像这样：
我希望它是这样开始的：
