The zoom of a viewport can be changed by setting the ViewHeight and ViewCenter of the viewports. This sample code iterates through all of the layouts and adjust this properties using the drawing extends information, so run the code in a drawing that has at least one entity.
[CommandMethod("changeZoom")]
static public void CommandChangeViewportZoom()
{
// access database and editor
Database db = Application.DocumentManager.
MdiActiveDocument.Database;
Editor ed = Application.DocumentManager.
MdiActiveDocument.Editor;
using (Transaction tr = db.
TransactionManager.StartTransaction())
{
LayoutManager layoutMgr = LayoutManager.Current;
Layout layoutObj;
DBDictionary layoutDict;
ed.WriteMessage("Number of Layouts = {0}\n",
layoutMgr.LayoutCount);
ed.WriteMessage("Current Layout = {0}\n",
layoutMgr.CurrentLayout);
Point3d x_Min = db.Extmin;
Point3d x_Max = db.Extmax;
using (layoutDict = tr.GetObject(db.LayoutDictionaryId,
OpenMode.ForRead) as DBDictionary)
{
foreach (DictionaryEntry layoutEntry in layoutDict)
{
using (layoutObj = tr.GetObject(
(ObjectId)(layoutEntry.Value),
OpenMode.ForRead) as Layout)
{
// Set the CurrentLayout to the layout
// if it is not Modelspace
if (layoutObj.LayoutName != "Model")
layoutMgr.CurrentLayout = layoutObj.LayoutName;
ed.WriteMessage("Layout Name = {0}\n",
layoutObj.LayoutName);
BlockTableRecord r = tr.GetObject(
layoutObj.BlockTableRecordId,
OpenMode.ForRead) as BlockTableRecord;
foreach (ObjectId obj in r)
{
DBObject dbobj = tr.GetObject(obj, OpenMode.ForRead);
Viewport vp = dbobj as Viewport;
if (vp != null)
{
ed.WriteMessage("\nnumber of Viewport = {0}",
vp.Number);
// get the screen aspect ratio to calculate
// the height and width
double mScrRatio;
// width/height
mScrRatio = (vp.Width / vp.Height);
Point3d mMaxExt = db.Extmax;
Point3d mMinExt = db.Extmin;
Extents3d mExtents = new Extents3d();
mExtents.Set(mMinExt, mMaxExt);
// prepare Matrix for DCS to WCS transformation
Matrix3d matWCS2DCS;
matWCS2DCS = Matrix3d.PlaneToWorld(vp.ViewDirection);
matWCS2DCS = Matrix3d.Displacement(
vp.ViewTarget - Point3d.Origin)
* matWCS2DCS;
matWCS2DCS = Matrix3d.Rotation(
-vp.TwistAngle, vp.ViewDirection,
vp.ViewTarget) * matWCS2DCS;
matWCS2DCS = matWCS2DCS.Inverse();
// tranform the extents to the DCS
// defined by the viewdir
mExtents.TransformBy(matWCS2DCS);
// width of the extents in current view
double mWidth;
mWidth = (mExtents.MaxPoint.X - mExtents.MinPoint.X);
// height of the extents in current view
double mHeight;
mHeight = (mExtents.MaxPoint.Y - mExtents.MinPoint.Y);
// get the view center point
Point2d mCentPt = new Point2d(
((mExtents.MaxPoint.X + mExtents.MinPoint.X) * 0.5),
((mExtents.MaxPoint.Y + mExtents.MinPoint.Y) * 0.5));
// check if the width 'fits' in current window,
// if not then get the new height as
// per the viewports aspect ratio
if (mWidth > (mHeight * mScrRatio))
mHeight = mWidth / mScrRatio;
// set the viewport parameters
if (vp.Number == 2)
{
vp.UpgradeOpen();
// set the view height - adjusted by 1%
vp.ViewHeight = mHeight * 1.01;
// set the view center
vp.ViewCenter = mCentPt;
vp.Visible = true;
vp.On = true;
vp.UpdateDisplay();
ed.SwitchToModelSpace();
Application.SetSystemVariable("CVPORT", vp.Number);
}
if (vp.Number == 3)
{
vp.UpgradeOpen();
vp.ViewHeight = mHeight * 1.25;
//set the view center
vp.ViewCenter = mCentPt;
vp.Visible = true;
vp.On = true;
vp.UpdateDisplay();
ed.SwitchToModelSpace();
Application.SetSystemVariable("CVPORT", vp.Number);
}
}
}
}
}
}
tr.Commit();
}
}
