ImageryLayerCollection - CesiumJS API 文档

new Cesium.ImageryLayerCollection()

An ordered collection of imagery layers for rendering raster imagery on a Globe or Cesium3DTileset.

Demo:

See:

Scene#imageryLayers for manipulating imagery layers on the globe.
Cesium3DTileset#imageryLayers for manipulating imagery layers on a 3D tileset.

Members

layerAdded : Event

当一个图层被添加到收藏中时会上升的事件。事件处理器通过层并添加索引.

Default Value: Event()

layerMoved : Event

当一个图层改变收藏中的位置时会提起的事件。事件处理器通过层移动,移动后它的新索引,移动前它的旧索引.

Default Value: Event()

layerRemoved : Event

当从收藏中移除一层时会提起的事件。事件处理器通过层并删除了该索引.

Default Value: Event()

layerShownOrHidden : Event

通过设置显示或隐藏一层时升起的事件 ImageryLayer#show property. Event handlers are passed a reference to this layer, 收藏中的图层索引,以及如果图层现在为真实的旗帜如果它现在被隐藏,则显示或虚假.

Default Value: Event()

length : number

获得此收藏中的层数 .

Methods

add(layer, index)

在收藏中添加一层.

Name	Type	Description
`layer`	ImageryLayer	要添加的图层.
`index`	number	optional 用于添加图层的索引。如果省略, 层会添加到所有现有层的顶部.

Throws:

DeveloperError : index, if supplied, must be greater than or equal to zero and less than or equal to the number of the layers.

Examples:

const imageryLayer = Cesium.ImageryLayer.fromWorldImagery();
scene.imageryLayers.add(imageryLayer);

const imageryLayer = Cesium.ImageryLayer.fromProviderAsync(Cesium.IonImageryProvider.fromAssetId(3812));
scene.imageryLayers.add(imageryLayer);

addImageryProvider(imageryProvider, index) → ImageryLayer

使用给定的图像渲染器创建新层,并添加到收藏中.

Name	Type	Description
`imageryProvider`	ImageryProvider	用于创建新图层的图像提供者.
`index`	number	optional 用于添加图层的索引。如果省略, 层会添加到所有现有层的顶部.

Returns:

新建的层.

Example:

try {
   const provider = await Cesium.IonImageryProvider.fromAssetId(3812);
   scene.imageryLayers.addImageryProvider(provider);
} catch (error) {
  console.log(`There was an error creating the imagery layer. ${error}`)
}

contains(layer) → boolean

检查收藏是否包含一个给定的图层 .

Name	Type	Description
`layer`	ImageryLayer	要检查的层.

Returns:

如果收藏中包含图层,则真实性为真,否则为假.

destroy()

Destroys the WebGL resources held by all layers in this collection. Explicitly destroying this 对象允许确定释放 NT 0 资源,而不是依赖垃圾 collector.

Once this object is destroyed, it should not be used; calling any function other than isDestroyed will result in a DeveloperError exception. Therefore, assign the return value (undefined) to the object as done in the example.

Throws:

DeveloperError : This object was destroyed, i.e., destroy() was called.

Example:

layerCollection = layerCollection && layerCollection.destroy();

See:

ImageryLayerCollection#isDestroyed

get(index) → ImageryLayer

从收藏中逐层获取索引.

Name	Type	Description
`index`	number	用于检索的索引.

Returns:

给定索引的图像层 .

indexOf(layer) → number

确定收藏中某一层的索引.

Name	Type	Description
`layer`	ImageryLayer	查找索引的图层 .

Returns:

收藏中层的索引,或 -1 如果收藏中不存在层的话.

isDestroyed() → boolean

如果此对象被销毁, 返回真实; 否则, 错误 .

If this object was destroyed, it should not be used; calling any function other than isDestroyed will result in a DeveloperError exception.

Returns:

如果此对象已被销毁, 则属真; 否则, 属假 .

See:

ImageryLayerCollection#destroy

lower(layer)

将收藏中一个位置下一层.

Name	Type	Description
`layer`	ImageryLayer	要移动的层.

Throws:

DeveloperError : layer is not in this collection.
DeveloperError : This object was destroyed, i.e., destroy() was called.

lowerToBottom(layer)

将一个层降低到收藏的底部.

Name	Type	Description
`layer`	ImageryLayer	要移动的层.

Throws:

DeveloperError : layer is not in this collection.
DeveloperError : This object was destroyed, i.e., destroy() was called.

pickImageryLayerFeatures(ray, scene) → Promise.<Array.<ImageryLayerFeatureInfo>>|undefined

同步地决定了被采光所交叉的图像层特征. 相交的图像 layer features are found by invoking ImageryProvider#pickFeatures for each imagery layer tile intersected by the pick ray. To compute a pick ray from a location on the screen, use Camera.getPickRay.

Name	Type	Description
`ray`	Ray	用来测试交叉点的射线.
`scene`	Scene	The scene.

Returns:

一个能解决一系列特征的许诺与采光相交. 如果能够迅速确定没有特征交叉(例如, 因为没有活跃的图像提供者支持 ImageryProvider#pickFeatures or because the pick ray does not intersect the surface), this function will return undefined.

Example:

const pickRay = viewer.camera.getPickRay(windowPosition);
const featuresPromise = viewer.imageryLayers.pickImageryLayerFeatures(pickRay, viewer.scene);
if (!Cesium.defined(featuresPromise)) {
    console.log('No features picked.');
} else {
    Promise.resolve(featuresPromise).then(function(features) {
        // This function is called asynchronously when the list if picked features is available.
        console.log(`Number of features: ${features.length}`);
        if (features.length > 0) {
            console.log(`First feature name: ${features[0].name}`);
        }
    });
}

pickImageryLayers(ray, scene) → Array.<ImageryLayer>|undefined

确定由采光线交叉的图像层。来计算从一个采光 location on the screen, use Camera.getPickRay.

Name	Type	Description
`ray`	Ray	用来测试交叉点的射线.
`scene`	Scene	The scene.

Returns:

一个包含全部的阵列由特定的采光线相交的层。未定义如果没有选择层次.

raise(layer)

将收藏中的一个位置提升一层.

Name	Type	Description
`layer`	ImageryLayer	要移动的层.

Throws:

DeveloperError : layer is not in this collection.
DeveloperError : This object was destroyed, i.e., destroy() was called.

raiseToTop(layer)

将一层升到收藏的顶端.

Name	Type	Description
`layer`	ImageryLayer	要移动的层.

Throws:

DeveloperError : layer is not in this collection.
DeveloperError : This object was destroyed, i.e., destroy() was called.

remove(layer, destroy) → boolean

如果存在, 从此收藏中删除一层 .

Name	Type	Default	Description
`layer`	ImageryLayer		要删除的图层 .
`destroy`	boolean	`真`	optional

Returns:

如果图层在收藏中被移除, 如果图层不在收藏中,则不真实.

removeAll(destroy)

从此收藏中删除所有层.

Name	Type	Default	Description
`destroy`	boolean	`真`	optional