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ee.Dictionary.evaluate
透過集合功能整理內容
你可以依據偏好儲存及分類內容。
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 |
|---|
Dictionary.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)
// A dictionary (e.g. results of ee.Image.reduceRegion of an S2 image).
var dictServer = ee.Dictionary({
B1: 182,
B2: 219,
B3: 443
});
// Use evaluate to transfer server-side dictionary to the client.
dictServer.evaluate(function(dictClient) {
print('Client-side dot notation to access "B1" value', dictClient.B1);
print('Client-side bracket notation to access "B1" value', dictClient['B1']);
print('Client-side operations to print all key-value pairs');
Object.keys(dictClient).forEach(function(key) {
print(' ' + key + ': ' + dictClient[key]);
});
});
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.Dictionary objects.
# Use ee.Dictionary.getInfo() instead.
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上次更新時間：2025-07-26 (世界標準時間)。
[null,null,["上次更新時間：2025-07-26 (世界標準時間)。"],[[["\u003cp\u003e\u003ccode\u003eDictionary.evaluate()\u003c/code\u003e asynchronously retrieves the value of a server-side ComputedObject (like a dictionary) and passes it to a callback function.\u003c/p\u003e\n"],["\u003cp\u003eThe provided callback function handles the server response, receiving the evaluated result on success or an error message on failure.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eDictionary.evaluate()\u003c/code\u003e enables client-side access and manipulation of the server-side dictionary data using standard JavaScript operations.\u003c/p\u003e\n"],["\u003cp\u003eWhile the JavaScript API uses \u003ccode\u003eDictionary.evaluate()\u003c/code\u003e, the Python API leverages \u003ccode\u003eDictionary.getInfo()\u003c/code\u003e for synchronous retrieval of dictionary values.\u003c/p\u003e\n"]]],["The `evaluate` method asynchronously retrieves a `ComputedObject`'s value from the server and provides it to a callback function. The callback receives a success argument with the result or a failure argument with an error message. It's demonstrated with a dictionary example where server-side data is transferred to the client-side. In Python, `getInfo()` is used instead of `evaluate` for `ee.Dictionary` objects. The provided table details the usage, argument types, and their specifics.\n"],null,["# ee.Dictionary.evaluate\n\n\u003cbr /\u003e\n\nAsynchronously retrieves the value of this object from the server and passes it to the provided callback function.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|---------------------------------|---------|\n| Dictionary.evaluate`(callback)` | |\n\n| Argument | Type | Details |\n|------------------------|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| this: `computedobject` | ComputedObject | The ComputedObject instance. |\n| `callback` | Function | A function of the form function(success, failure), called when the server returns an answer. If the request succeeded, the success argument contains the evaluated result. If the request failed, the failure argument will contains an error message. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// A dictionary (e.g. results of ee.Image.reduceRegion of an S2 image).\nvar dictServer = ee.Dictionary({\n B1: 182,\n B2: 219,\n B3: 443\n});\n\n// Use evaluate to transfer server-side dictionary to the client.\ndictServer.evaluate(function(dictClient) {\n print('Client-side dot notation to access \"B1\" value', dictClient.B1);\n print('Client-side bracket notation to access \"B1\" value', dictClient['B1']);\n\n print('Client-side operations to print all key-value pairs');\n Object.keys(dictClient).forEach(function(key) {\n print(' ' + key + ': ' + dictClient[key]);\n });\n});\n```\nPython setup\n\nSee the [Python Environment](/earth-engine/guides/python_install) page for information on the Python API and using\n`geemap` for interactive development. \n\n```python\nimport ee\nimport geemap.core as geemap\n```\n\n### Colab (Python)\n\n```python\n# The Earth Engine Python client library does not have an evaluate method for\n# asynchronous evaluation of ee.Dictionary objects.\n# Use ee.Dictionary.getInfo() instead.\n```"]]
