添加项目文件。

DotNet.Revit.ViewTransform/ViewTransformHelper.cs

@@ -0,0 +1,54 @@
+using Autodesk.Revit.DB;
+using Autodesk.Revit.UI;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace DotNet.Revit.ViewTransform
+{
+    public static class ViewTransformHelper
+    {
+        /// <summary>
+        /// 屏幕点转为空间三维点.
+        /// </summary>
+        /// <param name="view">指定转换到的视图.</param>
+        /// <param name="point">指定屏幕上的点.</param>
+        /// <returns></returns>
+        public static XYZ ScreenToWorld(this View view, System.Drawing.Point point)
+        {
+            if (view == null)
+                throw new NullReferenceException();
+
+            var uiDoc = new UIDocument(view.Document);
+            var uiView = uiDoc.GetOpenUIViews().FirstOrDefault(m => m.ViewId == view.Id);
+
+            if (uiView == null)
+                throw new NullReferenceException();
+
+            var rect = uiView.GetWindowRectangle();
+            var corners = uiView.GetZoomCorners();
+
+            var mousePoint = new XYZ(point.X, point.Y, 0);
+
+            var screenLeftlower = new XYZ(rect.Left, rect.Bottom, 0);
+            var screenRightupper = new XYZ(rect.Right, rect.Top, 0);
+
+            // 换算比例
+            var scale = corners[0].DistanceTo(corners[1])
+                / screenLeftlower.DistanceTo(screenRightupper);
+
+            var xdis = (point.X - screenLeftlower.X) * scale;
+            var ydis = (screenLeftlower.Y - point.Y) * scale;
+
+            var vp = uiDoc.ActiveView.UpDirection;
+            var vr = uiDoc.ActiveView.RightDirection;
+
+            var distance = mousePoint.DistanceTo(screenLeftlower) * scale;
+            var result = corners[0] + vr * xdis + vp * ydis;
+
+            return result;
+        }
+    }
+}