ProEssentials是一個非常好用的實時曲線繪圖控件，它對繪制圖表以及圖表分析功能所需要的數(shù)據(jù)和方法進行了簡單封裝，可以輕松實現(xiàn)專業(yè)圖表軟件的效果。本文討論ProEssentials坐標注釋(Annotations)的使用以及如何創(chuàng)建自定義的坐標刻度。

用Line Annotations創(chuàng)建坐標刻度

禁用掉ProEssentials默認刻度，使用自定義的刻度線和網(wǎng)格線。

自定義Y軸的參數(shù)：

自定義X軸的參數(shù)：

下面這段代碼顯示了如何創(chuàng)建一個帶有文本標簽的Y軸：

'** Disable default scale **'

Pego1.ShowYAxis = PESA_EMPTY


'** Generally, a custom y axis will need manual range control **'

Pego1.ManualScaleControlY = PEMSC_MINMAX

Pego1.ManualMinY = 0

Pego1.ManualMaxY = 1000


'** Create custom grid lines with HorzLineAnnotations **'

'** Note that GridLineControl will control these annotations **'

Pego1.HorzLineAnnotation(0) = 200

Pego1.HorzLineAnnotationType(0) = PELAT_GRIDLINE

Pego1.HorzLineAnnotationText(0) = "|LLow Value"

 
Pego1.HorzLineAnnotation(1) = 500

Pego1.HorzLineAnnotationType(1) = PELAT_GRIDLINE

Pego1.HorzLineAnnotationText(1) = "|LMedium Value"


Pego1.HorzLineAnnotation(2) = 800

Pego1.HorzLineAnnotationType(2) = PELAT_GRIDLINE

Pego1.HorzLineAnnotationText(2) = "|LHigh Value"
 

Pego1.HorzLineAnnotation(3) = 350

Pego1.HorzLineAnnotationType(3) = PELAT_GRIDTICK

Pego1.HorzLineAnnotationText(3) = ""
 

Pego1.HorzLineAnnotation(4) = 650

Pego1.HorzLineAnnotationType(4) = PELAT_GRIDTICK

Pego1.HorzLineAnnotationText(4) = ""


'** Set LeftMargin to allocate space for line annotation text **'

'** Use the longest string used in annotations.

Pego1.LeftMargin = "Medium Value "


'** Set this to see annotations **'

Pego1.ShowAnnotations = True
 

'** Increase line annotation text size **'

Pego1.LineAnnotationTextSize = 100


'** Put Grid In Front **'

Pego1.GridInFront = True

如圖所示：

用CustomGridNumber Event自定義坐標刻度

使用CustomGridNumber Event，可以改變坐標上的文本表現(xiàn)形式。當以下屬性設(shè)置為True時，將會啟動相應(yīng)的事件進程：