CAD.NET图像的缩放Scale

操作方法

在CAD操作中SCALE缩放命令的用法：输入SC或SCALE命令，选择要缩入的对象-选择基点-输入缩放比例参数-空格完成。

代码实现

使用API实现的关键点：调用Entity的TransformBy方法。如下：

/// <summary>
/// 缩放
/// </summary>
/// <param name="id">数据ID</param>
/// <param name="basePoint">基点</param>
/// <param name="scale">缩放比例参数-</param>
public static void Scale(ObjectId id, Point3d basePoint, double scale)
{
    Matrix3d transform = Matrix3d.Scaling(scale, basePoint);

    Database db = id.Database;

    using (Transaction tr = db.TransactionManager.StartTransaction())
    {
        try
        {
            Entity ent = (Entity)tr.GetObject(id, OpenMode.ForWrite);

            if (ent != null)
            {
                ent.TransformBy(transform);
            }

            tr.Commit();

        }
        catch (Autodesk.AutoCAD.Runtime.Exception ex)
        {
            AcadApp.ShowAlertDialog(ex.Message);
        }
    }
}