cad二次开发直径标注

CAD二次开发中的直径标注可以通过建立一个DimensionTools类来实现。直径标注的参数主要有圆心坐标、直径值和引线长度等。代码实现如下：

public static void addDiameterDimension(Point3d center, double diameter, double leaderLength)
{
    using (Transaction trans = db.TransactionManager.StartOpenCloseTransaction())
    {
        AlignedDimension dimAligned = new AlignedDimension();
        dimAligned.XLine1Point = center.PolarPoint(GeTools.DegreeToRadian(0), diameter / 2);
        dimAligned.XLine2Point = center.PolarPoint(GeTools.DegreeToRadian(180), diameter / 2);
        dimAligned.DimLinePoint = center.PolarPoint(GeTools.DegreeToRadian(-90), leaderLength);
        dimAligned.DimensionText = "<>" + diameter.ToString();
        dimAligned.DimensionStyle = db.Dimstyle;
        db.AddToModelSpace(dimAligned, "Dim");
    }
}

其中，AlignedDimension表示直径标注，XLine1Point和XLine2Point表示直径两端点的坐标，DimLinePoint表示引线的终点坐标，DimensionText表示标注的主尺寸值，DimensionStyle表示标注的样式。