CAD交互绘制带周长面积的矩形框（com接口）

主要用到函数说明：

_DMxDrawX::DrawLine

绘制一个直线。详细说明如下：

_DMxDrawX::DrawText

绘制一个单行文字。详细说明如下：

IMxDrawCustomEntity::Draw

把实体绘制到图上。一般用于动态拖放时，在拖放结束时，绘制到图上。

c#中实现代码说明：

动态拖放时的绘制事件：

private void DynDrawMatrix()
{
    // 创建一个与用户交互取点的对象。
    MxDrawPoint point1 = (MxDrawPoint)axMxDrawX1.GetPoint(false, 0, 0, "\n 点取开始点:");
    if (point1 == null)
    {
        return;
    }
    MxDrawUiPrPoint getSecondPt = new MxDrawUiPrPoint();
    getSecondPt.message = "第二点";
    getSecondPt.basePoint = point1;
    //调用
    MxDrawCustomEntity spDrawData = getSecondPt.InitUserDraw("TestDynDrawMatrix");
    // 设置动态绘制参数.
    spDrawData.SetPoint("BasePoint", point1);
    // 开始取第二个点。
    if (getSecondPt.go() != MCAD_McUiPrStatus.mcOk)
        return;
    spDrawData.Draw();
}

动态绘制矩形框：

private void axMxDrawX1_DynWorldDraw(object sender, AxMxDrawXLib._DMxDrawXEvents_DynWorldDrawEvent e)
{
    MxDrawCustomEntity pCustomEntity = (MxDrawCustomEntity)e.pData;
    MxDrawWorldDraw pWorldDraw = (MxDrawWorldDraw)e.pWorldDraw;
    string sGuid = pCustomEntity.Guid;
    MxDrawPoint curPoint = new MxDrawPoint();
    curPoint.x = e.dX;
curPoint.y = e.dY;
    if(sGuid == "TestDynDrawMatrix")
    {
        //与用户交互在图面上提取一个点
        MxDrawPoint vBasePt = pCustomEntity.GetPoint("BasePoint");
        //计算中心点位置
        MxDrawPoint centerPt = new MxDrawPoint();
        {
            centerPt.x = curPoint.x + (vBasePt.x - curPoint.x) / 2;
            centerPt.y = curPoint.y + (vBasePt.y - curPoint.y) / 2;
        }
        //计算面积（取绝对值）
        double arec = Math.Abs(vBasePt.x - curPoint.x) * Math.Abs(vBasePt.y - curPoint.y);
        //计算周长
        double girth = 2 * (Math.Abs(vBasePt.x - curPoint.x) + Math.Abs(vBasePt.y - curPoint.y));
        //变换视区长度
        double dHeigth = axMxDrawX1.ViewLongToDocCoord(15);
        //绘制一个单行文字
        //参数一为文字的位置的X坐标 ；参数二为文字的位置的Y坐标 ；参数三为文字内容字符串
        //参数四为文字高度；参数五为文字的旋转角度
        //参数六为文字的水平对齐方式,0=kTextLeft,1=kTextCenter,2=kTextRight
        //参数七文字的竖直对齐方式,1=kTextBottom,2=kTextVertMid,3=kTextTop
        pWorldDraw.DrawText(centerPt.x, centerPt.y, "面积：" + arec, dHeigth, 0, MCAD_McHorizontalAlignment.mcHorizontalAlignmentCenter, MCAD_McVerticalAlignment.mcVerticalAlignmentBottom);
        pWorldDraw.DrawText(centerPt.x, centerPt.y, "周长：" + girth, dHeigth, 0, MCAD_McHorizontalAlignment.mcHorizontalAlignmentCenter, MCAD_McVerticalAlignment.mcVerticalAlignmentTop);
        //绘制一个直线
        //参数一直线的开始点x坐标，参数二直线的开始点y坐标，参数三直线的结束点x坐标，参数四直线的结束点y坐标
        pWorldDraw.DrawLine(vBasePt.x, vBasePt.y, vBasePt.x, curPoint.y);
        pWorldDraw.DrawLine(vBasePt.x, curPoint.y, curPoint.x, curPoint.y);
        pWorldDraw.DrawLine(curPoint.x, curPoint.y, curPoint.x, vBasePt.y);
        pWorldDraw.DrawLine(curPoint.x, vBasePt.y, vBasePt.x, vBasePt.y);
    }
}

原文地址：https://www.cnblogs.com/yzy0224/p/11064821.html