在cad使用过程中，用户可以绘制自定义实体。点击此处下载演示实例。
调用DrawCustomEntity函数，绘制一个自定义实体对象。
下面代码绘制一个自定义实体，C#代码实现如下：
private void DrawMlineCommand()
{
MxDrawUiPrPoint getPt = new MxDrawUiPrPoint();
getPt.message = "点取第一点";
if (getPt.go() != MCAD_McUiPrStatus.mcOk)
{
return;
}
var frstPt = getPt.value();
if (frstPt == null)
{
return;
}
MxDrawUiPrPoint getSecondPt = new MxDrawUiPrPoint();
getSecondPt.message = "点取第二点";
getSecondPt.basePoint = frstPt;
getSecondPt.setUseBasePt(false);
MxDrawCustomEntity spDrawData = getSecondPt.InitUserDraw("DrawCustEntity");
spDrawData.SetDouble("Width", 30);
spDrawData.SetPoint("Point1", frstPt);
Int32 lCount = 1;
spDrawData.SetLong("Count", 1);
while (true)
{
if (getSecondPt.go() != MCAD_McUiPrStatus.mcOk)
break;
var secondPt = getSecondPt.value();
if (secondPt == null)
break;
lCount++;
String sPointName = "Point" + lCount.ToString();
spDrawData.SetPoint(sPointName, secondPt);
spDrawData.SetLong("Count", lCount);
}
if (lCount > 1)
axMxDrawX1.DrawEntity(spDrawData);
}
需要响应DMxDrawXEvents::CustomEntity_Explode事件。
下面例子，得到自实体的数据，C#代码实现如下：
private void axMxDrawX1_CustomEntity_Explode(object sender, AxMxDrawXLib._DMxDrawXEvents_CustomEntity_ExplodeEvent e)
{
MxDrawCustomEntity pCustomEntity = (MxDrawCustomEntity)e.pCustomEntity;
var sGuid = pCustomEntity.Guid;
MxDrawWorldDraw pWorldDraw = (MxDrawWorldDraw)e.pDraw;
if (sGuid == "DrawCustEntity")
{
MyDrawMline(pWorldDraw, pCustomEntity, null);
e.pRet = 1;
}
}
private void MyDrawMline(MxDrawWorldDraw pWorldDraw, MxDrawCustomEntity pCustomEntity, MxDrawPoint curPt)
{
// 取自定义实体的端点数目，属性。
if (!pCustomEntity.IsHave("Count"))
return;
long lCount = pCustomEntity.GetLong("Count");
MxDrawPolyline tmpPl = new MxDrawPolyline();
for (long i = 0; i < lCount; i++)
{
String sName;
sName = "Point" + (i + 1).ToString();
if (!pCustomEntity.IsHave(sName))
break;
// 取自定义实体的端点坐标。
MxDrawPoint pt = pCustomEntity.GetPoint(sName);
// 把端点坐标，传给pl线，用于生成双线。
tmpPl.AddVertexAt(pt);
}
if (curPt != null)
tmpPl.AddVertexAt(curPt);
if (tmpPl.NumVerts < 2)
{
// 端点数少于2就，不构成直线，就不需要显示。
return;
}
// 求pl线，开始点的导数.
MxDrawVector3d vecFx;
if (!tmpPl.GetFirstDeriv(tmpPl.GetStartParam(), out vecFx))
return;
if (vecFx.IsZeroLength())
return;
// 把向量旋转90度.
vecFx.RotateByXyPlan(3.14159265 / 2.0);
vecFx.Normalize();
// 得到双线的宽度属性。
double dWidth = pCustomEntity.GetDouble("Width");
vecFx.Mult(dWidth);
MxDrawPoint startPt = tmpPl.GetStartPoint();
// 向pl线，两个方向偏移，
MxDrawPoint offsetPt1 = new MxDrawPoint();
offsetPt1.x = startPt.x;
offsetPt1.y = startPt.y;
offsetPt1.Add(vecFx);
MxDrawPoint offsetPt2 = new MxDrawPoint();
offsetPt2.x = startPt.x;
offsetPt2.y = startPt.y;
offsetPt2.Sum(vecFx);
MxDrawText text = new MxDrawText();
text.TextString = "Test";
text.Height = 100;
text.Position = startPt;
text.AlignmentPoint = startPt;
MxDrawPoint pt1, pt2;
text.GetBoundingBox(out pt1, out pt2);
MxDrawPoint pt3 = new MxDrawPoint();
pt3.x = pt1.x;
pt3.y = pt2.y;
MxDrawPoint pt4 = new MxDrawPoint();
pt4.x = pt2.x;
pt4.y = pt1.y;
MxDrawPoints pts = new MxDrawPoints();
pts.Add(pt1.x, pt1.y, 0);
pts.Add(pt3.x, pt3.y, 0);
pts.Add(pt2.x, pt2.y, 0);
pts.Add(pt4.x, pt4.y, 0);
Int32 lDraworder = pWorldDraw.Draworder;
pWorldDraw.Draworder = lDraworder + 1;
pWorldDraw.DrawWipeout(pts);
pWorldDraw.Draworder = lDraworder + 2;
pWorldDraw.DrawEntity((MxDrawEntity)text);
pWorldDraw.Draworder = lDraworder;
// pWorldDraw->
{
MxDrawResbuf newobj;
if (tmpPl.OffsetCurves(dWidth, offsetPt1, out newobj))
{
for (Int32 j = 0; j < newobj.Count; j++)
{
MxDrawEntity tmpObj = (MxDrawEntity)newobj.AtObject(j);
if (tmpObj == null)
continue;
pWorldDraw.DrawEntity(tmpObj);
}
newobj.RemoveAll();
}
}
{
MxDrawResbuf newobj;
if (tmpPl.OffsetCurves(dWidth, offsetPt2, out newobj))
{
for (Int32 j = 0; j < newobj.Count; j++)
{
MxDrawEntity tmpObj = (MxDrawEntity)newobj.AtObject(j);
if (tmpObj == null)
continue;
pWorldDraw.DrawEntity(tmpObj);
}
// 这不使用newobj，需要显示调用RemoveAll函数清楚内存。
// 不然这个可能就会程序退出时才释放，这时它会去释放控件对象指针，有可能会出错。
newobj.RemoveAll();
}
}
}
C#代码实现如下：
private void axMxDrawX1_DynWorldDraw(object sender, AxMxDrawXLib._DMxDrawXEvents_DynWorldDrawEvent e)
{
MxDrawCustomEntity pCustomEntity = (MxDrawCustomEntity)e.pData;
String sGuid = pCustomEntity.Guid;
e.pRet = 0;
MxDrawWorldDraw pWorldDraw = (MxDrawWorldDraw)e.pWorldDraw;
MxDrawPoint curPt = new MxDrawPoint();
curPt.x = e.dX;
curPt.y = e.dY;
if (sGuid == "DrawCustEntity")
{
MyDrawMline(pWorldDraw, pCustomEntity, curPt);
}
}
需要响应_DMxDrawXEvents::CustomEntity_getGripPoints事件，C#代码实现如下：
private void axMxDrawX1_CustomEntity_getGripPoints(object sender, AxMxDrawXLib._DMxDrawXEvents_CustomEntity_getGripPointsEvent e)
{
MxDrawCustomEntity pCustomEntity = (MxDrawCustomEntity)e.pCustomEntity;
var sGuid = pCustomEntity.Guid;
e.pOk = 0;
if (sGuid == "DrawCustEntity")
{
if (!pCustomEntity.IsHave("Count"))
return;
long lCount = pCustomEntity.GetLong("Count");
MxDrawResbuf ret = (MxDrawResbuf)axMxDrawX1.NewResbuf();
for (long i = 0; i < lCount; i++)
{
String sName;
sName = "Point" + (i + 1).ToString();
if (!pCustomEntity.IsHave(sName))
break;
// 取自定义实体的端点坐标。
MxDrawPoint pt = pCustomEntity.GetPoint(sName);
ret.AddPoint(pt);
}
e.pOk = 1;
axMxDrawX1.SetEventRetEx(ret);
}
}
需要响应CustomEntity_moveGripPointsAt事件。
下面例子，夹点移动后，修改自定义实体的属性，C#代码实现如下：
private void axMxDrawX1_CustomEntity_moveGripPointsAt(object sender, AxMxDrawXLib._DMxDrawXEvents_CustomEntity_moveGripPointsAtEvent e)
{
e.pRet = 1;
MxDrawCustomEntity pCustomEntity = (MxDrawCustomEntity)e.pCustomEntity;
var sGuid = pCustomEntity.Guid;
if (sGuid == "DrawCustEntity")
{
if (!pCustomEntity.IsHave("Count"))
return;
long lCount = pCustomEntity.GetLong("Count");
for (long i = 0; i < lCount; i++)
{
String sName;
sName = "Point" + (i + 1).ToString();
if (!pCustomEntity.IsHave(sName))
break;
// 取自定义实体的端点坐标。
MxDrawPoint pt = pCustomEntity.GetPoint(sName);
if (i == e.lGridIndex)
{
pt.x = pt.x + e.dOffsetX;
pt.y = pt.y + e.dOffsetY;
pCustomEntity.SetPoint(sName, pt);
}
}
}
}