修正TiKnob的指示箭头显示问题

箭头显示问题"/>

修正TiKnob的指示箭头显示问题

iocom官方只支持到D7,但是可以运用于新版本，只测试过显示运用，没测试过OPC特性(这个在新版本运用中估计有问题)。

但是在新版本运用中还有有一些小BUG，比如：

修正TiAnlogDisplay显示的问题-CSDN博客

TiKnob也发现BUG。

在10.4中拖入一个TiKnob，发现“Indicator”没有显示出来，

修改 

procedure TiKnob.DrawIndicator(Canvas: TCanvas; const CenterPoint: TPoint);
varInnerPoint           : TPoint;OuterPoint           : TPoint;IndicatorCenterPoint : Tpoint;IndicatorRect        : TRect;IndicatorDegrees     : Double;PointerEndPoint      : TPoint;PointerBasePoint     : TPoint;Point1               : TPoint;Point2               : Tpoint;
beginIndicatorDegrees := RotationStartDegrees - PositionDegrees;//with Canvas, IndicatorRect dowith Canvas dobeginBrush.Style := bsSolid;IndicatorCenterPoint := GetXYRadPoint(IndicatorDegrees, FKnobRadius - FIndicatorMargin - FIndicatorSize, CenterPoint);IndicatorRect := Rect(IndicatorCenterPoint.x - FIndicatorSize,IndicatorCenterPoint.y - FIndicatorSize,IndicatorCenterPoint.x + FIndicatorSize,IndicatorCenterPoint.y + FIndicatorSize);if FMouseDown or FKeyDown then begin Pen.Color := FIndicatorActiveColor;   Brush.Color := FIndicatorActiveColor    endelse                           begin Pen.Color := FIndicatorInactiveColor; Brush.Color := FIndicatorInactiveColor; end;case FIndicatorStyle ofikisDotLowered : beginEllipse(IndicatorRect.Left, IndicatorRect.Top, IndicatorRect.Right, IndicatorRect.Bottom);Pen.Color := clGray;  Arc(IndicatorRect.Left, IndicatorRect.Top, IndicatorRect.Right, IndicatorRect.Bottom, IndicatorRect.Right, IndicatorRect.Top, IndicatorRect.Left, IndicatorRect.Bottom);Pen.Color := clWhite; Arc(IndicatorRect.Left, IndicatorRect.Top, IndicatorRect.Right, IndicatorRect.Bottom, IndicatorRect.Left , IndicatorRect.Bottom, IndicatorRect.Right, IndicatorRect.Top);end;ikisDotRaised  : beginEllipse(IndicatorRect.Left, IndicatorRect.Top, IndicatorRect.Right, IndicatorRect.Bottom);Pen.Color := clWhite; Arc(IndicatorRect.Left, IndicatorRect.Top, IndicatorRect.Right, IndicatorRect.Bottom, IndicatorRect.Right, IndicatorRect.Top, IndicatorRect.Left, IndicatorRect.Bottom);Pen.Color := clGray;  Arc(IndicatorRect.Left, IndicatorRect.Top, IndicatorRect.Right, IndicatorRect.Bottom, IndicatorRect.Left, IndicatorRect.Bottom, IndicatorRect.Right, IndicatorRect.Top);end;ikisDot        : beginEllipse(IndicatorRect.Left, IndicatorRect.Top, IndicatorRect.Right, IndicatorRect.Bottom);end;ikisLineCenter : beginOuterPoint:=GetXYRadPoint(IndicatorDegrees,FKnobRadius-FIndicatorMargin,CenterPoint);PolyLine([OuterPoint, CenterPoint]);end;ikisLineCustom : beginOuterPoint:=GetXYRadPoint(IndicatorDegrees,FKnobRadius-FIndicatorMargin,               CenterPoint);InnerPoint:=GetXYRadPoint(IndicatorDegrees,FKnobRadius-FIndicatorMargin-FIndicatorSize,CenterPoint);PolyLine([OuterPoint, InnerPoint]);end;ikisTriangle   : beginPointerEndPoint :=GetXYRadPoint(IndicatorDegrees,FKnobRadius-FIndicatorMargin,               CenterPoint);PointerBasePoint:=GetXYRadPoint(IndicatorDegrees,FKnobRadius-FIndicatorMargin-FIndicatorSize,CenterPoint);Point1 := GetXYRadPoint(IndicatorDegrees + 90, FIndicatorSize/2, PointerBasePoint);Point2 := GetXYRadPoint(IndicatorDegrees - 90, FIndicatorSize/2, PointerBasePoint);Polygon([Point1, Point2, PointerEndPoint]);end;end;end;
end;

是由于Canvas和IndicatorRect都有Left和Top属性引起的。

重新编译(不用重新安装)，正常 。

估计其它控件也有类似的问题，一般照此修改就可以。