private static void RemoveBlock()
{
DxfDocument dxf = new DxfDocument();
Block block = new Block("MyBlock");
Line line1 = new Line(new Vector3(-5, -5, 0), new Vector3(5, 5, 0));
Line line2 = new Line(new Vector3(5, -5, 0), new Vector3(-5, 5, 0));
block.Entities.Add(line1);
block.Entities.Add(line2);
Insert insert = new Insert(block);
dxf.AddEntity(insert);
bool ok;
// line1 is used by block and cannot be removed (ok = false)
ok = dxf.RemoveEntity(line1);
// block is used by insert and cannot be removed (ok = false)
ok = dxf.Blocks.Remove(block);
// it is safe to remove insert, it doesn't belong to anybody (ok = true)
ok = dxf.RemoveEntity(insert);
// it is safe to remove block, it doesn't belong to anybody (ok = true)
// at the same time, all entities that were part of the block have been also removed
ok = dxf.Blocks.Remove(block);
// obj is null the line1 does not exist in the document, the block was removed
DxfObject obj = dxf.GetObjectByHandle(line1.Handle);
Console.WriteLine("Press a key...");
Console.ReadKey();
}