#### # new UrlTemplateImageryProvider(options)

网络瓦片图层

#### 参数:

名称 | 类型 | 默认值 | 描述
--- | --- | --- | ---
`options` | Object |  | 初始化参数

`url`

Cesium.Resource | string

null

服务基地址，详见Cesium.Resource，有如下关键字:

- `{z}`: The level of the tile in the tiling scheme. Level zero is the root of the quadtree pyramid.
- `{x}`: The tile X coordinate in the tiling scheme, where 0 is the Westernmost tile.
- `{y}`: The tile Y coordinate in the tiling scheme, where 0 is the Northernmost tile.
- `{s}`: One of the available subdomains, used to overcome browser limits on the number of simultaneous requests per host.
- `{reverseX}`: The tile X coordinate in the tiling scheme, where 0 is the Easternmost tile.
- `{reverseY}`: The tile Y coordinate in the tiling scheme, where 0 is the Southernmost tile.
- `{reverseZ}`: The level of the tile in the tiling scheme, where level zero is the maximum level of the quadtree pyramid. In order to use reverseZ, maximumLevel must be defined.
- `{westDegrees}`: The Western edge of the tile in geodetic degrees.
- `{southDegrees}`: The Southern edge of the tile in geodetic degrees.
- `{eastDegrees}`: The Eastern edge of the tile in geodetic degrees.
- `{northDegrees}`: The Northern edge of the tile in geodetic degrees.
- `{westProjected}`: The Western edge of the tile in projected coordinates of the tiling scheme.
- `{southProjected}`: The Southern edge of the tile in projected coordinates of the tiling scheme.
- `{eastProjected}`: The Eastern edge of the tile in projected coordinates of the tiling scheme.
- `{northProjected}`: The Northern edge of the tile in projected coordinates of the tiling scheme.
- `{width}`: The width of each tile in pixels.
- `{height}`: The height of each tile in pixels.

`rectangle` | Cesium.Rectangle | Cesium.Rectangle.MAX_VALUE | 图层显示范围，超出范围不会额外请求瓦片，详见Cesium.Rectangle
`extensions` | Array.<Object> | [] | 扩展参数，会将扩展参数中的非空参数拼接到请求接口上，示例：[{ key: '参数名', value: '参数值' }]
`isStretchImage` | Boolean | false | 超过最大最小层级范围图像是否进行图像的拉伸。此值未定义或者设置为true时,如果图像level小于minimumLevel或者大于maximumLevel，图像会进行拉伸。反之，如果图像level小于minimumLevel或者大于maximumLevel，不会再请求图像以及拉伸图像
`tileWidth` | number | 256 | 请求瓦片宽度
`tileHeight` | number | 256 | 请求瓦片高度
`minimumLevel` | number | 0 | 图层最小请求瓦片级别，小于该级别不再请求瓦片
`maximumLevel` | number |  | 图层最大请求瓦片级别，大于该级别不再请求瓦片
`ellipsoid` | Cesium.Ellipsoid | Cesium.Ellipsoid.default | 椭球体对象，详见Cesium.Ellipsoid
`credit` | Cesium.Credit | string | null | 场景上显示的数据源的信息，当使用MapGIS发布的Cesium库时，该功能失效，详见Cesium.Credit

`pickFeaturesUrl`

Resource | string

null

The URL template to use to pick features. If this property is not specified, `UrlTemplateImageryProvider#pickFeatures` will immediately returned undefined, indicating no features picked. The URL template supports all of the keywords supported by the `url` parameter, plus the following:

- `{i}`: The pixel column (horizontal coordinate) of the picked position, where the Westernmost pixel is 0.
- `{j}`: The pixel row (vertical coordinate) of the picked position, where the Northernmost pixel is 0.
- `{reverseI}`: The pixel column (horizontal coordinate) of the picked position, where the Easternmost pixel is 0.
- `{reverseJ}`: The pixel row (vertical coordinate) of the picked position, where the Southernmost pixel is 0.
- `{longitudeDegrees}`: The longitude of the picked position in degrees.
- `{latitudeDegrees}`: The latitude of the picked position in degrees.
- `{longitudeProjected}`: The longitude of the picked position in the projected coordinates of the tiling scheme.
- `{latitudeProjected}`: The latitude of the picked position in the projected coordinates of the tiling scheme.
- `{format}`: The format in which to get feature information, as specified in the `GetFeatureInfoFormat`.

详见Cesium.Resource

`urlSchemeZeroPadding`

object

null

Gets the URL scheme zero padding for each tile coordinate. The format is '000' where each coordinate will be padded on the left with zeros to match the width of the passed string of zeros. e.g. Setting: urlSchemeZeroPadding : { '{x}' : '0000'} will cause an 'x' value of 12 to return the string '0012' for {x} in the generated URL. It the passed object has the following keywords:

- `{z}`: The zero padding for the level of the tile in the tiling scheme.
- `{x}`: The zero padding for the tile X coordinate in the tiling scheme.
- `{y}`: The zero padding for the the tile Y coordinate in the tiling scheme.
- `{reverseX}`: The zero padding for the tile reverseX coordinate in the tiling scheme.
- `{reverseY}`: The zero padding for the tile reverseY coordinate in the tiling scheme.
- `{reverseZ}`: The zero padding for the reverseZ coordinate of the tile in the tiling scheme.

`subdomains` | string | Array.<string> | 'abc' | The subdomains to use for the `{s}` placeholder in the URL template. If this parameter is a single string, each character in the string is a subdomain. If it is an array, each element in the array is a subdomain.
`tilingScheme` | Cesium.TilingScheme | CustomTilingScheme | Cesium.WebMercatorTilingScheme | 瓦片平铺方案，详见Cesium.TilingScheme

`hasAlphaChannel`

boolean

true

true if the images provided by this imagery provider include an alpha channel; otherwise, false. If this property is false, an alpha channel, if present, will be ignored. If this property is true, any images without an alpha channel will be treated as if their alpha is 1.0 everywhere. When this property is false, memory usage and texture upload time are potentially reduced.

`getFeatureInfoFormats` | Array.<GetFeatureInfoFormat> |  | The formats in which to get feature information at a specific location when `UrlTemplateImageryProvider#pickFeatures` is invoked. If this parameter is not specified, feature picking is disabled.

`enablePickFeatures`

boolean

true

If true, `UrlTemplateImageryProvider#pickFeatures` will request the `pickFeaturesUrl` and attempt to interpret the features included in the response. If false, `UrlTemplateImageryProvider#pickFeatures` will immediately return undefined (indicating no pickable features) without communicating with the server. Set this property to false if you know your data source does not support picking features or if you don't want this provider's features to be pickable. Note that this can be dynamically overridden by modifying the `UriTemplateImageryProvider#enablePickFeatures` property.

`tileDiscardPolicy` | TileDiscardPolicy | null | A policy for discarding tile images according to some criteria 详见Cesium.TileDiscardPolicy
`customTags` | Object | null | Allow to replace custom keywords in the URL template. The object must have strings as keys and functions as values.

##### 请参考以下示例：

1、百度地图
2、高德地图
3、影像图层高程模式设置
4、卷帘
5、加载自定义裁图方式地图
6、地表透明度独立控制