The GetPoint method prompts the user to specify a point at the Command prompt. The PromptPointOptions object allows you to control the input entered and how the prompt message appears. The UseBasePoint and BasePoint properties of the PromptPointOptions object controls if a rubber-band line is drawn from a base point. The Keywords property of the PromptPointOptions object allows you to define keywords that can be entered at the Command prompt in addition to specifying a point.
The following example prompts the user for two points, then draws a line using those points as the start point and endpoint.
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Runtime;
[CommandMethod("GetPointsFromUser")]
public static void GetPointsFromUser()
{
// Get the current database and start the Transaction Manager
Document acDoc = Application.DocumentManager.MdiActiveDocument;
Database acCurDb = acDoc.Database;
PromptPointResult pPtRes;
PromptPointOptions pPtOpts = new PromptPointOptions("");
// Prompt for the start point
pPtOpts.Message = "\nEnter the start point of the line: ";
pPtRes = acDoc.Editor.GetPoint(pPtOpts);
Point3d ptStart = pPtRes.Value;
// Exit if the user presses ESC or cancels the command
if (pPtRes.Status == PromptStatus.Cancel) return;
// Prompt for the end point
pPtOpts.Message = "\nEnter the end point of the line: ";
pPtOpts.UseBasePoint = true;
pPtOpts.BasePoint = ptStart;
pPtRes = acDoc.Editor.GetPoint(pPtOpts);
Point3d ptEnd = pPtRes.Value;
if (pPtRes.Status == PromptStatus.Cancel) return;
// Start a transaction
using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
{
BlockTable acBlkTbl;
BlockTableRecord acBlkTblRec;
// Open Model space for write
acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId,
OpenMode.ForRead) as BlockTable;
acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],
OpenMode.ForWrite) as BlockTableRecord;
// Define the new line
using (Line acLine = new Line(ptStart, ptEnd))
{
// Add the line to the drawing
acBlkTblRec.AppendEntity(acLine);
acTrans.AddNewlyCreatedDBObject(acLine, true);
}
// Zoom to the extents or limits of the drawing
acDoc.SendStringToExecute("._zoom _all ", true, false, false);
// Commit the changes and dispose of the transaction
acTrans.Commit();
}
}