public static CanvasDraw GetCanvasSize(double controlActualWidth, double controlActualHeight, int canvasWidth, int canvasHeight)
{
CanvasDraw cc = new CanvasDraw();
double availableWidth = controlActualWidth - CanvasMargin * 2;
double availableHeight = controlActualHeight - CanvasMargin * 2;
if (canvasWidth <= availableWidth && canvasHeight <= availableHeight)//不需要缩放
{
cc.CanvasWidth = canvasWidth;
cc.CanvasHeight = canvasHeight;
}
else//需要缩放
{
double finalWidth = Math.Min(canvasWidth, availableWidth);
var finalHeight = finalWidth * canvasHeight / canvasWidth;
if (finalHeight > availableHeight)
{
finalHeight = availableHeight;
finalWidth = finalHeight * canvasWidth / canvasHeight;
}
cc.CanvasWidth = finalWidth;
cc.CanvasHeight = finalHeight;
}
cc.Left = (controlActualWidth - cc.CanvasWidth) / 2;
cc.Top = (controlActualHeight - cc.CanvasHeight) / 2;
cc.Ratio = cc.CanvasWidth / canvasWidth;
return(cc);
}
private void init()
{
theCanvas.Children.Clear();
border = new Rectangle();
canvasDraw = CanosSizeUtility.GetCanvasSize(theCanvas.ActualWidth, theCanvas.ActualHeight, this.CanvasWidth, this.CanvasHeight);
border.Width = canvasDraw.CanvasWidth;
border.Height = canvasDraw.CanvasHeight;
border.SetValue(Canvas.LeftProperty, canvasDraw.Left);
border.SetValue(Canvas.TopProperty, canvasDraw.Top);
border.Stroke = Brushes.LightBlue;
border.StrokeThickness = 1;
this.theCanvas.Children.Add(border);
}