浩淼的天空:AO里面的MapGrid对象模型

       mapgrid也就是所谓的地图网格，它必须存在layout视图而不会在map视图中出现，在mapgrid模型里面，主要有四个内容：

       1.mapgrid及其子类，其子类都是coclass，可以创建

       2.mapgrid的border类，创建网格的边缘

       3.mapgrid的label类，创建边缘的标签

       4.mapgridfactory，它可以依据默认的属性快速创建一个mapgrid

       在arcmap里面，看起来map和pagelayout都是视图的一种，map管理layer，而pagelayout管理layout,但是实际上，map与pagelayout都实现了iactiveview和igraphicscontainer接口，但是实际上是pagelayout管理着mapframe,mapsurroundframe和elementframe,其中mapframe管理了map和mapgrid对象。

mapsurroundframe管理了指北针，legend,mapinset等对象 

       下面是一个mapgrid的例子：

Sub MapGrid()

    '找到当前所使用的MapFrame

    Dim pMxDoc As

IMxDocument

    Dim pMap As IMap

    Dim pGrahpicsContainer As

IGraphicsContainer

    Dim pMapFrame As IMapFrame

    Set pMxDoc =

ThisDocument

    Set pMap = pMxDoc.FocusMap

    Set pGrahpicsContainer =

pMxDoc.PageLayout

    Set pMapFrame =

pGrahpicsContainer.FindFrame(pMap)

'生成一个Mapgrid对象，生成最简单的graticule网格

    Dim pMapGrid As IMapGrid

    Dim

pMeasuredGrid As IMeasuredGrid

    Set pMeasuredGrid = New Graticule

Set pMapGrid = pMeasuredGrid

    pMeasuredGrid.FixedOrigin =

True

    pMeasuredGrid.XIntervalSize = 10

    pMeasuredGrid.XOrigin =

-180

    pMeasuredGrid.YIntervalSize = 10

    pMeasuredGrid.YOrigin =

-90

    '生成mapgrid的border

    Dim pCalibrateBorder As

ICalibratedMapGridBorder

    Set pCalibrateBorder = New

CalibratedMapGridBorder

    Dim pBackColor As IColor

    Dim pForeColor As

IColor

    Set pBackColor = New RgbColor

    Set pForeColor = New

RgbColor

    pBackColor.RGB = RGB(255, 255, 0)

    pForeColor.RGB = RGB(0,

255, 0)

    pCalibrateBorder.BackgroundColor = pBackColor

pCalibrateBorder.ForegroundColor = pForeColor

pCalibrateBorder.Alternating = True

    pCalibrateBorder.BorderWidth =

10

    pCalibrateBorder.Interval = 72

    '生成mapgrid的label

Dim pFormattedGridLabel As IFormattedGridLabel

    Set pFormattedGridLabel =

New FormattedGridLabel

    Dim pNumericFormat As INumericFormat

    Set

pNumericFormat = New NumericFormat

    pNumericFormat.AlignmentOption =

esriAlignLeft

    pNumericFormat.RoundingOption =

esriRoundNumberOfDecimals

    pNumericFormat.RoundingValue = 2

pNumericFormat.ShowPlusSign = False

    pNumericFormat.UseSeparator =

True

    pNumericFormat.ZeroPad = True

    pFormattedGridLabel.Format =

pNumericFormat

    '添加属性到mapgrid里面

    pMapGrid.Border =

pCalibrateBorder

    pMapGrid.LabelFormat = pFormattedGridLabel

'把这个Grid添加进地图里面，注意是MAPframe在管理

    Dim pMapGrids As IMapGrids

    Set

pMapGrids = pMapFrame

    Dim pActiveView As IActiveView

    Set

pActiveView = pMxDoc.PageLayout

    pMapGrids.AddMapGrid

pMapGrid

    pActiveView.PartialRefresh esriViewBackground, Nothing,

Nothing

End Sub

这段代码是VBA的，还没有转到控件上使用。