Instructions for use
A snapshot layer is a special layer group. All layers in a snapshot layer group are snapshot layers of the map. The rendering method of snapshot layers is unique: they are rendered only when first displayed. When browsing the map thereafter, if the map's visible bounds do not change, snapshot layers will not be re-rendered, meaning they do not refresh with the map refresh. If the map's visible bounds change, it automatically triggers the refresh and rendering of snapshot layers. Snapshot layers are one way to improve map display performance.
Since snapshot layers are special layer groups, you can add group layer objects (LayerGroup) to a snapshot layer. However, you cannot add snapshot layers to a snapshot layer, and you cannot add snapshot layers to a group layer object (LayerGroup object).
Application Scenario: During mapping, some layers have large data volumes, which can affect map refresh efficiency. In such cases, you can add layers with low refresh frequency, large data volumes, and mandatory display to snapshot layers. Without changing the map's visible bounds, layers in the snapshot layer group will not refresh, improving map display performance.
Feature Access
- Layer Manager -> drop-down button in the top-left corner -> New Snapshot Group.
- Layer Manager -> context menu in the blank area -> New Snapshot Group.
Operation Steps
- In the blank area of the Layer Manager, right-click and select the New Snapshot Group option to create a snapshot layer group.
- Select one or more layers and move them to the snapshot layer group. These layers will become snapshot layers. When the map extent does not change, the layers under the snapshot layer group will not refresh.
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