/// <summary>
/// 预览按钮处理。
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void Preview(object sender, RoutedEventArgs e)
{
try
{
// 生成边坡实体集合，按实体边界获取截取窗口。
previewEnts = MakeBianpo(view);
var extents = new AcDb.Extents3d();
foreach (var ent in previewEnts.OfType <AcDb.Curve>())
{
extents.AddExtents(ent.GeometricExtents);
}
previewExtents = extents;
// 生成Bitmap，显示到界面的图片上。
using (var bitmap = GraphicHelper.Snapshort(previewEnts,
kPreviewImageWidth, kPreviewImageHeight,
previewExtents.MinPoint, previewExtents.MaxPoint))
{
ShowImage(bitmap);
}
}
catch (Exception ex)
{
ShowError(ex);
}
}
private void PreviewImage_MouseWheel(object sender, MouseWheelEventArgs e)
{
try
{
if (previewEnts == null)
{
return;
}
// 在鼠标位置放大一倍。
if (!isPreviewImageZooming && e.Delta > 0)
{
isPreviewImageZooming = true;
// 将原预览实体范围扩展为与图片比例相同，以准确定位扩大点。
var minPoint = previewExtents.MinPoint;
var maxPoint = previewExtents.MaxPoint;
var origWidth = maxPoint.X - minPoint.X;
var origHeight = maxPoint.Y - minPoint.Y;
var origRatio = origHeight > 0 ? (origWidth / origHeight) : 1;
var prevImgRatio = kPreviewImageWidth / kPreviewImageHeight;
if (origRatio > prevImgRatio) // 过宽。
{
var heightDiff = origWidth / prevImgRatio - origHeight;
minPoint = new Point3d(minPoint.X, minPoint.Y - heightDiff * 0.5, 0);
maxPoint = new Point3d(maxPoint.X, maxPoint.Y + heightDiff * 0.5, 0);
}
else if (origRatio < prevImgRatio) // 过高。
{
var widthDiff = origHeight * prevImgRatio - origWidth;
minPoint = new Point3d(minPoint.X - widthDiff * 0.5, minPoint.Y, 0);
maxPoint = new Point3d(maxPoint.X + widthDiff * 0.5, maxPoint.Y, 0);
}
// 获取缩放后的截取窗口。
var zoomPtOnImg = e.GetPosition(PreviewImage);
zoomPtOnImg = new System.Windows.Point(
zoomPtOnImg.X * kPreviewImageWidth / PreviewImage.ActualWidth,
zoomPtOnImg.Y * kPreviewImageHeight / PreviewImage.ActualHeight);
var zoomVec = maxPoint - minPoint;
var zoomPt = new Point3d(
minPoint.X + zoomVec.X * zoomPtOnImg.X / kPreviewImageWidth,
maxPoint.Y - zoomVec.X * zoomPtOnImg.Y / kPreviewImageHeight,
0);
// 生成Bitmap，显示到界面的图片上。
using (var bitmap = GraphicHelper.Snapshort(previewEnts,
kPreviewImageWidth, kPreviewImageHeight,
zoomPt - zoomVec * 0.25, zoomPt + zoomVec * 0.25))
{
ShowImage(bitmap);
}
}
// 还原。
if (isPreviewImageZooming && e.Delta < 0)
{
isPreviewImageZooming = false;
// 生成Bitmap，显示到界面的图片上。
using (var bitmap = GraphicHelper.Snapshort(previewEnts,
kPreviewImageWidth, kPreviewImageHeight,
previewExtents.MinPoint, previewExtents.MaxPoint))
{
ShowImage(bitmap);
}
}
}
catch (Exception ex)
{
ShowError(ex);
}
}