Describes a polyline. The first two positions define a line segment,
and each additional position defines a line segment from the previous position. The segments
can be linear connected points, great arcs, or clamped to terrain.
    
| 参数名称 | 类型 | 描述信息 | 
|---|---|---|
| options | PolylineGraphics.ConstructorOptions | 可选 Object describing initialization options | 
Demo:
参考:
成员(属性)
arcType : Property|undefined
    Gets or sets the 
ArcType Property specifying whether the line segments should be great arcs, rhumb lines or linearly connected.
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    默认值:
    
ArcType.GEODESIC
    
    
    
    
    
    
    
clampToGround : Property|undefined
    Gets or sets the boolean Property specifying whether the polyline
should be clamped to the ground.
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    默认值:
    
false
    
    
    
    
    
    
    
classificationType : Property|undefined
    Gets or sets the 
ClassificationType Property specifying whether this polyline will classify terrain, 3D Tiles, or both when on the ground.
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    默认值:
    
ClassificationType.BOTH
    
    
    
    
    
    
    
readonly definitionChanged : Event
    Gets the event that is raised whenever a property or sub-property is changed or modified.
depthFailMaterial : MaterialProperty
    Gets or sets the Property specifying the material used to draw the polyline when it fails the depth test.
Requires the EXT_frag_depth WebGL extension to render properly. If the extension is not supported, there may be artifacts.
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    默认值:
    
undefined
    
    
    
    
    
    
    
distanceDisplayCondition : Property|undefined
    Gets or sets the 
DistanceDisplayCondition Property specifying at what distance from the camera that this polyline will be displayed.
granularity : Property|undefined
    Gets or sets the numeric Property specifying the angular distance between each latitude and longitude if arcType is not ArcType.NONE and clampToGround is false.
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    默认值:
    
Cesium.Math.RADIANS_PER_DEGREE
    
    
    
    
    
    
    
    Gets or sets the Property specifying the material used to draw the polyline.
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    默认值:
    
Color.WHITE
    
    
    
    
    
    
    
positions : Property|undefined
    Gets or sets the Property specifying the array of 
Cartesian3
positions that define the line strip.
shadows : Property|undefined
    Get or sets the enum Property specifying whether the polyline
casts or receives shadows from light sources.
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    默认值:
    
ShadowMode.DISABLED
    
    
    
    
    
    
    
show : Property|undefined
    Gets or sets the boolean Property specifying the visibility of the polyline.
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    默认值:
    
true
    
    
    
    
    
    
    
width : Property|undefined
    Gets or sets the numeric Property specifying the width in pixels.
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    默认值:
    
1.0
    
    
    
    
    
    
    
zIndex : ConstantProperty|undefined
    Gets or sets the zIndex Property specifying the ordering of the polyline. Only has an effect if `clampToGround` is true and polylines on terrain is supported.
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    默认值:
    
0
    
    
    
    
    
    
    
方法
clone(result) → PolylineGraphics
    Duplicates this instance.
    
| 参数名称 | 类型 | 描述信息 | 
|---|---|---|
| result | PolylineGraphics | 可选 The object onto which to store the result. | 
返回值:
    The modified result parameter or a new instance if one was not provided.
    
    Assigns each unassigned property on this object to the value
of the same property on the provided source object.
    
| 参数名称 | 类型 | 描述信息 | 
|---|---|---|
| source | PolylineGraphics | The object to be merged into this object. | 
定义的类型
    Initialization options for the PolylineGraphics constructor
属性:
| 属性名称 | 类型 | 可选 | 默认值 | 描述信息 | 
|---|---|---|---|---|
| show | Property | boolean | <可选> | true | A boolean Property specifying the visibility of the polyline. | 
| positions | Property | Array.<Cartesian3> | <可选> | A Property specifying the array of Cartesian3positions that define the line strip. | |
| width | Property | number | <可选> | 1.0 | A numeric Property specifying the width in pixels. | 
| granularity | Property | number | <可选> | Cesium.Math.RADIANS_PER_DEGREE | A numeric Property specifying the angular distance between each latitude and longitude if arcType is not ArcType.NONE. | 
| material | MaterialProperty | Color | <可选> | Color.WHITE | A Property specifying the material used to draw the polyline. | 
| depthFailMaterial | MaterialProperty | Color | <可选> | A property specifying the material used to draw the polyline when it is below the terrain. | |
| arcType | Property | ArcType | <可选> | ArcType.GEODESIC | The type of line the polyline segments must follow. | 
| clampToGround | Property | boolean | <可选> | false | A boolean Property specifying whether the Polyline should be clamped to the ground. | 
| shadows | Property | ShadowMode | <可选> | ShadowMode.DISABLED | An enum Property specifying whether the polyline casts or receives shadows from light sources. | 
| distanceDisplayCondition | Property | DistanceDisplayCondition | <可选> | A Property specifying at what distance from the camera that this polyline will be displayed. | |
| classificationType | Property | ClassificationType | <可选> | ClassificationType.BOTH | An enum Property specifying whether this polyline will classify terrain, 3D Tiles, or both when on the ground. | 
| zIndex | Property | number | <可选> | 0 | A Property specifying the zIndex used for ordering ground geometry. Only has an effect if `clampToGround` is true and polylines on terrain is supported. | 
