08.09.17

1.If you want to edit an dimension entity,you should add the entity into the database first.And then,open it ,so you edit it now.

After everthing is done,you should close it also .

2.Pointer altering

AcDbAlignedDimension::cast(pEnt);

The cast function change the entity style pointer pEnt into a AcDbAlignedDimension style pointer.

3.ads_point From,To;

From[X],From[Y],From[Z];

From,To are arrays.

X,Y,Z are all capital letters,not lowcases or small letters.

4.global functions

When designing ,you can use a global function directly with ::

In the declaration , you should add static in front of the function or variable in the .h document.

For example:

static int a;

static int f(int a);

5.one Id -> AcDbObjectId

two or more Ids-> AcDbObjectIdArray

6.Why????????????

I'm not happy!!!!!!!!