ee.String.evaluate

從伺服器非同步擷取這個物件的值，並傳遞至提供的回呼函式。

用量	傳回
String.evaluate(callback)

引數	類型	詳細資料
這個：computedobject	ComputedObject	ComputedObject 例項。
callback	函式	伺服器傳回答案時呼叫的函式，格式為 function(success, failure)。如果要求成功，success 引數會包含評估結果。如果要求失敗，失敗引數會包含錯誤訊息。

範例

程式碼編輯器 (JavaScript)

/**
 * WARNING: this function transfers data from Earth Engine servers to the
 * client. Doing so can negatively affect request processing and client
 * performance. Server-side options should be used whenever possible.
 * Learn more about the distinction between server and client:
 * https://developers.google.com/earth-engine/guides/client_server
 */

// A server-side ee.String object fetched from a feature property.
var stringServer = ee.Feature(null, {lc: 'grassland'}).getString('lc');

// Use evaluate to transfer server-side string to client for use in ui.Label.
stringServer.evaluate(function(stringClient) {
  print('Client-side primitive data type', typeof stringClient);  // string
  print('Client-side string', stringClient);  // grassland
  print('Client-side string used in ui.Label',
        ui.Label('Land cover: ' + stringClient));  // Land cover: grassland
});

Python 設定

請參閱 Python 環境頁面，瞭解 Python API 和如何使用 geemap 進行互動式開發。

import ee
import geemap.core as geemap

Colab (Python)

# The Earth Engine Python client library does not have an evaluate method for
# asynchronous evaluation of ee.String objects.
# Use ee.String.getInfo() instead.