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ui.Map.DrawingTools.onLayerSelect
使用集合让一切井井有条
根据您的偏好保存内容并对其进行分类。
注册在选择图层时触发的回调。
返回一个 ID，该 ID 可传递给 unlisten() 以取消注册回调。
| 用法 | 返回 |
|---|
DrawingTools.onLayerSelect(callback) | 字符串 |
| 参数 | 类型 | 详细信息 |
|---|
此：ui.map.drawingtools | ui.Map.DrawingTools | ui.Map.DrawingTools 实例。 |
callback | 函数 | 选择形状时要触发的回调。回调会传递两个参数：所选的 GeometryLayer（如果取消选择，则为 null）以及事件监听器所绑定的 ui.Map.DrawingTools widget。 |
如未另行说明，那么本页面中的内容已根据知识共享署名 4.0 许可获得了许可，并且代码示例已根据 Apache 2.0 许可获得了许可。有关详情，请参阅 Google 开发者网站政策。Java 是 Oracle 和/或其关联公司的注册商标。
最后更新时间 (UTC)：2025-07-26。
[null,null,["最后更新时间 (UTC)：2025-07-26。"],[[["\u003cp\u003eRegisters a callback function that is executed when a layer is selected within the DrawingTools.\u003c/p\u003e\n"],["\u003cp\u003eProvides a method, \u003ccode\u003eonLayerSelect\u003c/code\u003e, to register the callback, accepting the callback function as an argument and returning a unique ID.\u003c/p\u003e\n"],["\u003cp\u003eThe callback function receives the selected GeometryLayer (or null if deselected) and the DrawingTools widget as parameters.\u003c/p\u003e\n"],["\u003cp\u003eThe returned ID can be utilized with the \u003ccode\u003eunlisten()\u003c/code\u003e method to unregister the callback when it's no longer needed.\u003c/p\u003e\n"]]],["A callback function is registered to be executed upon layer selection. The `onLayerSelect` method takes a callback as an argument, which receives the selected `GeometryLayer` (or null if deselected) and the `ui.Map.DrawingTools` instance. This method returns a unique string ID, enabling the callback to be unregistered later via the `unlisten()` method. The method's `ui.Map.DrawingTools` instance is implicitly bound to this.\n"],null,["# ui.Map.DrawingTools.onLayerSelect\n\n\u003cbr /\u003e\n\nRegisters a callback that's fired when a layer is selected.\n\n\u003cbr /\u003e\n\nReturns an ID which can be passed to unlisten() to unregister the callback.\n\n| Usage | Returns |\n|----------------------------------------|---------|\n| DrawingTools.onLayerSelect`(callback)` | String |\n\n| Argument | Type | Details |\n|-----------------------------|---------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| this: `ui.map.drawingtools` | ui.Map.DrawingTools | The ui.Map.DrawingTools instance. |\n| `callback` | Function | The callback to fire when a shape is selected. The callback is passed two parameters: the selected GeometryLayer (or null for deselect) and the ui.Map.DrawingTools widget that the event listener is bound to. |"]]
