19. 使用矢量瓦片 — QGIS Documentation 文档

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19.3. 矢量瓦片数据集属性  

The vector tiles Layer Properties dialog provides the following sections:

Information

Source

Symbology ^[1]

Labels ^[1]

Rendering

Metadata

^[1] 也可在图层样式面板中使用

19.3.1. 信息属性  

Information 选项卡为只读状态，这是引人关注的位置，可以快速获取当前图层的摘要信息和元数据。提供的信息包括：

基于图层的提供程序：名称、URI、源类型和路径、缩放级别的数量

坐标参照系：名称、单位、方法、精度、参照 (即静态还是动态)

从已填充的元数据中提取：访问、范围、链接、联系人、历史记录等

19.3.2. 源属性  

The Source tab displays basic information about the selected vector tile, including:

the Layer name to display in the Layers Panel ;

the Coordinate Reference System : Displays the layer's Coordinate Reference System (CRS) . You can change the layer's CRS, by selecting a recently used one in the drop-down list or clicking on the ^{Select CRS} button (see Coordinate Reference System Selector ). Use this process only if the layer CRS is wrong or not specified.

19.3.3.1. Setting rules 

As vector tiles consist of point, line and polygon geometries, the respective symbols are available. To apply a cartographic style (with symbology and/or labels), you can either:

Use a Style URL when creating the Vector Tiles Connection . The symbology will be shown immediately in the Symbology tab after the layer is loaded in QGIS.

Or build your own symbology and labeling in the corresponding tabs of the layer properties. By default, QGIS assigns an identical symbol to the features based on their geometry type.

In both cases, setting a style for a vector tile relies on a set of rules applied to the features, indicating:

a vector symbol or label

a Label , a title for comprehensive identification of the rule

the name of a particular Layer the rule should apply to, if not applied to (all layers)

a Min. Zoom and a Max. Zoom , for the range of display. Symbology and labeling can be dependent on the zoom level.

a Filter , a QGIS expression to identify the features to apply the style to

Each rule is added pressing the ^{Add rule} button and selecting the type of symbols ( Marker , Line , Fill ) corresponding to the features geometry type. You can as well ^{Remove selected rules} or ^{Edit current rule} .

At the bottom the Current Zoom is shown. Check the Visible rules only option at the top of the dialog to filter the list of rules to only those that are visible at the current zoom level. This makes it easier to work with complex vector styling and to locate troublesome rules. The Filter rules text box also helps you easily find a rule, by searching the Label , Layer and Filter fields.

In 图 19.3 we set up style for the OpenStreetMap landuse layer. For better visibility most of the rules are deselected.

19.3.3.2. Layer rendering 

From the Symbology tab, you can also set some options that invariably act on all features of the layer:

Opacity : You can make the underlying layer in the map canvas visible with this tool. Use the slider to adapt the visibility of your vector layer to your needs. You can also make a precise definition of the percentage of visibility in the menu beside the slider.

Blending mode : You can achieve special rendering effects with these tools that you may previously only know from graphics programs. The pixels of your overlaying and underlaying layers are mixed through the settings described in Blending Modes .

19.3.3.3. Styles 

Available at the bottom of most of the tabs, the Styles ► menu provides shortcuts to save, load, create, switch styles to apply to the vector tiles. Vector tiles can have their style saved from QGIS as QML files and they can be imported as:

QML files ( QML - QGIS样式文件格式 )

MapBox GL Json style configuration files

More details at 保存和共享图层属性 .

19.3.4. Rendering Properties 

Under Scale dependent visibility , you can set the Maximum (inclusive) and Minimum (exclusive) scales, defining a range of scales in which features will be visible. Out of this range, they are hidden. The ^{Set to current canvas scale} button helps you use the current map canvas scale as boundary of the range visibility. See 可见比例选择器 for more information.

图 19.4 Vector Tiles Properties - Rendering Dialog 

19.3.5. 元数据属性  

The Metadata tab provides you with options to create and edit a metadata report on your layer. See 元数据 for more information.