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本頁面由 Cloud Translation API 翻譯而成。

使用 Gemini API 生成文字
bookmark_border 透過集合功能整理內容你可以依據偏好儲存及分類內容。

您可以要求 Gemini 模型根據僅限文字提示或多模態提示生成文字。使用 Firebase AI Logic 時，您可以直接透過應用程式提出這項要求。

多模態提示可包含多種輸入內容 (例如文字、圖片、PDF、純文字檔案、音訊和影片)。

本指南說明如何根據純文字提示和包含檔案的基本多模態提示產生文字。

跳至僅文字輸入的程式碼範例跳至多模式輸入的程式碼範例

如需其他文字處理選項，請參閱其他指南
產生結構化輸出內容多輪對話雙向串流在裝置上產生文字根據文字產生圖片

事前準備

按一下 Gemini API 供應商，即可在這個頁面上查看供應商專屬內容和程式碼。

如果您尚未完成，請參閱入門指南，瞭解如何設定 Firebase 專案、將應用程式連結至 Firebase、新增 SDK、為所選 Gemini API 供應器初始化後端服務，以及建立 GenerativeModel 例項。

如要測試並重複提示，甚至取得產生的程式碼片段，建議您使用 Google AI Studio。

從純文字輸入內容生成文字

在嘗試這個範例之前，請先完成本指南「開始前」一節，設定專案和應用程式。
在該部分，您也需要點選所選Gemini API供應商的按鈕，才能在本頁面上看到供應商專屬內容。

您可以使用文字輸入提示，要求 Gemini 模型生成文字。

Swift KotlinJavaWebDart Unity

您可以呼叫 generateContent()，根據純文字輸入內容產生文字。


import FirebaseAI

// Initialize the Gemini Developer API backend service
let ai = FirebaseAI.firebaseAI(backend: .googleAI())

// Create a `GenerativeModel` instance with a model that supports your use case
let model = ai.generativeModel(modelName: "gemini-2.0-flash")


// Provide a prompt that contains text
let prompt = "Write a story about a magic backpack."

// To generate text output, call generateContent with the text input
let response = try await model.generateContent(prompt)
print(response.text ?? "No text in response.")

您可以呼叫 generateContent()，根據純文字輸入內容產生文字。

^{對於 Kotlin，這個 SDK 中的函式為暫停函式，需要從協同程式範圍中呼叫。}


// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
val model = Firebase.ai(backend = GenerativeBackend.googleAI())
                        .generativeModel("gemini-2.0-flash")


// Provide a prompt that contains text
val prompt = "Write a story about a magic backpack."

// To generate text output, call generateContent with the text input
val response = generativeModel.generateContent(prompt)
print(response.text)

您可以呼叫 generateContent()，根據純文字輸入內容產生文字。

^{對於 Java，這個 SDK 中的各個方法會傳回 ListenableFuture。}


// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
GenerativeModel ai = FirebaseAI.getInstance(GenerativeBackend.googleAI())
        .generativeModel("gemini-2.0-flash");

// Use the GenerativeModelFutures Java compatibility layer which offers
// support for ListenableFuture and Publisher APIs
GenerativeModelFutures model = GenerativeModelFutures.from(ai);


// Provide a prompt that contains text
Content prompt = new Content.Builder()
    .addText("Write a story about a magic backpack.")
    .build();

// To generate text output, call generateContent with the text input
ListenableFuture<GenerateContentResponse> response = model.generateContent(prompt);
Futures.addCallback(response, new FutureCallback<GenerateContentResponse>() {
    @Override
    public void onSuccess(GenerateContentResponse result) {
        String resultText = result.getText();
        System.out.println(resultText);
    }

    @Override
    public void onFailure(Throwable t) {
        t.printStackTrace();
    }
}, executor);

您可以呼叫 generateContent()，根據純文字輸入內容產生文字。


import { initializeApp } from "firebase/app";
import { getAI, getGenerativeModel, GoogleAIBackend } from "firebase/ai";

// TODO(developer) Replace the following with your app's Firebase configuration
// See: https://firebase.google.com/docs/web/learn-more#config-object
const firebaseConfig = {
  // ...
};

// Initialize FirebaseApp
const firebaseApp = initializeApp(firebaseConfig);

// Initialize the Gemini Developer API backend service
const ai = getAI(firebaseApp, { backend: new GoogleAIBackend() });

// Create a `GenerativeModel` instance with a model that supports your use case
const model = getGenerativeModel(ai, { model: "gemini-2.0-flash" });


// Wrap in an async function so you can use await
async function run() {
  // Provide a prompt that contains text
  const prompt = "Write a story about a magic backpack."

  // To generate text output, call generateContent with the text input
  const result = await model.generateContent(prompt);

  const response = result.response;
  const text = response.text();
  console.log(text);
}

run();

您可以呼叫 generateContent()，從純文字輸入內容產生文字。


import 'package:firebase_ai/firebase_ai.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';

// Initialize FirebaseApp
await Firebase.initializeApp(
  options: DefaultFirebaseOptions.currentPlatform,
);

// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
final model =
      FirebaseAI.googleAI().generativeModel(model: 'gemini-2.0-flash');


// Provide a prompt that contains text
final prompt = [Content.text('Write a story about a magic backpack.')];

// To generate text output, call generateContent with the text input
final response = await model.generateContent(prompt);
print(response.text);

您可以呼叫 GenerateContentAsync()，根據純文字輸入內容產生文字。


using Firebase;
using Firebase.AI;

// Initialize the Gemini Developer API backend service
var ai = FirebaseAI.GetInstance(FirebaseAI.Backend.GoogleAI());

// Create a `GenerativeModel` instance with a model that supports your use case
var model = ai.GetGenerativeModel(modelName: "gemini-2.0-flash");


// Provide a prompt that contains text
var prompt = "Write a story about a magic backpack.";

// To generate text output, call GenerateContentAsync with the text input
var response = await model.GenerateContentAsync(prompt);
UnityEngine.Debug.Log(response.Text ?? "No text in response.");

使用文字和檔案 (多模態) 輸入內容產生文字

您可以要求 Gemini 模型透過文字和檔案提示來產生文字，方法是提供每個輸入檔案的 mimeType 和檔案本身。請參閱本頁後續的輸入檔案相關規定和建議。

以下範例說明如何從檔案輸入內容中產生文字，方法是分析以內嵌資料 (base64 編碼檔案) 形式提供的單一影片檔案。

請注意，此範例顯示如何在內文中提供檔案，但 SDK 也支援提供 YouTube 網址。

需要影片檔案範例嗎？

您可以使用這份公開檔案，MIME 類型為 video/mp4 (查看或下載檔案)。 https://storage.googleapis.com/cloud-samples-data/video/animals.mp4

Swift KotlinJavaWebDart Unity

您可以呼叫 generateContent() 來根據文字和影片檔案的多模態輸入內容生成文字。


import FirebaseAI

// Initialize the Gemini Developer API backend service
let ai = FirebaseAI.firebaseAI(backend: .googleAI())

// Create a `GenerativeModel` instance with a model that supports your use case
let model = ai.generativeModel(modelName: "gemini-2.0-flash")


// Provide the video as `Data` with the appropriate MIME type.
let video = InlineDataPart(data: try Data(contentsOf: videoURL), mimeType: "video/mp4")

// Provide a text prompt to include with the video
let prompt = "What is in the video?"

// To generate text output, call generateContent with the text and video
let response = try await model.generateContent(video, prompt)
print(response.text ?? "No text in response.")

您可以呼叫 generateContent() 來根據文字和影片檔案的多模態輸入內容生成文字。

^{對於 Kotlin，這個 SDK 中的函式為暫停函式，需要從協同程式範圍中呼叫。}


// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
val model = Firebase.ai(backend = GenerativeBackend.googleAI())
                        .generativeModel("gemini-2.0-flash")


val contentResolver = applicationContext.contentResolver
contentResolver.openInputStream(videoUri).use { stream ->
  stream?.let {
    val bytes = stream.readBytes()

    // Provide a prompt that includes the video specified above and text
    val prompt = content {
        inlineData(bytes, "video/mp4")
        text("What is in the video?")
    }

    // To generate text output, call generateContent with the prompt
    val response = generativeModel.generateContent(prompt)
    Log.d(TAG, response.text ?: "")
  }
}

您可以呼叫 generateContent() 來根據文字和影片檔案的多模態輸入內容生成文字。

^{對於 Java，這個 SDK 中的各個方法會傳回 ListenableFuture。}


// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
GenerativeModel ai = FirebaseAI.getInstance(GenerativeBackend.googleAI())
        .generativeModel("gemini-2.0-flash");

// Use the GenerativeModelFutures Java compatibility layer which offers
// support for ListenableFuture and Publisher APIs
GenerativeModelFutures model = GenerativeModelFutures.from(ai);


ContentResolver resolver = getApplicationContext().getContentResolver();
try (InputStream stream = resolver.openInputStream(videoUri)) {
    File videoFile = new File(new URI(videoUri.toString()));
    int videoSize = (int) videoFile.length();
    byte[] videoBytes = new byte[videoSize];
    if (stream != null) {
        stream.read(videoBytes, 0, videoBytes.length);
        stream.close();

        // Provide a prompt that includes the video specified above and text
        Content prompt = new Content.Builder()
                .addInlineData(videoBytes, "video/mp4")
                .addText("What is in the video?")
                .build();

        // To generate text output, call generateContent with the prompt
        ListenableFuture<GenerateContentResponse> response = model.generateContent(prompt);
        Futures.addCallback(response, new FutureCallback<GenerateContentResponse>() {
            @Override
            public void onSuccess(GenerateContentResponse result) {
                String resultText = result.getText();
                System.out.println(resultText);
            }

            @Override
            public void onFailure(Throwable t) {
                t.printStackTrace();
            }
        }, executor);
    }
} catch (IOException e) {
    e.printStackTrace();
} catch (URISyntaxException e) {
    e.printStackTrace();
}

您可以呼叫 generateContent() 來根據文字和影片檔案的多模態輸入內容生成文字。


import { initializeApp } from "firebase/app";
import { getAI, getGenerativeModel, GoogleAIBackend } from "firebase/ai";

// TODO(developer) Replace the following with your app's Firebase configuration
// See: https://firebase.google.com/docs/web/learn-more#config-object
const firebaseConfig = {
  // ...
};

// Initialize FirebaseApp
const firebaseApp = initializeApp(firebaseConfig);

// Initialize the Gemini Developer API backend service
const ai = getAI(firebaseApp, { backend: new GoogleAIBackend() });

// Create a `GenerativeModel` instance with a model that supports your use case
const model = getGenerativeModel(ai, { model: "gemini-2.0-flash" });


// Converts a File object to a Part object.
async function fileToGenerativePart(file) {
  const base64EncodedDataPromise = new Promise((resolve) => {
    const reader = new FileReader();
    reader.onloadend = () => resolve(reader.result.split(',')[1]);
    reader.readAsDataURL(file);
  });
  return {
    inlineData: { data: await base64EncodedDataPromise, mimeType: file.type },
  };
}

async function run() {
  // Provide a text prompt to include with the video
  const prompt = "What do you see?";

  const fileInputEl = document.querySelector("input[type=file]");
  const videoPart = await fileToGenerativePart(fileInputEl.files[0]);

  // To generate text output, call generateContent with the text and video
  const result = await model.generateContent([prompt, videoPart]);

  const response = result.response;
  const text = response.text();
  console.log(text);
}

run();

您可以呼叫 generateContent() 來根據文字和影片檔案的多模態輸入內容生成文字。


import 'package:firebase_ai/firebase_ai.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';

// Initialize FirebaseApp
await Firebase.initializeApp(
  options: DefaultFirebaseOptions.currentPlatform,
);

// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
final model =
      FirebaseAI.googleAI().generativeModel(model: 'gemini-2.0-flash');


// Provide a text prompt to include with the video
final prompt = TextPart("What's in the video?");

// Prepare video for input
final video = await File('video0.mp4').readAsBytes();

// Provide the video as `Data` with the appropriate mimetype
final videoPart = InlineDataPart('video/mp4', video);

// To generate text output, call generateContent with the text and images
final response = await model.generateContent([
  Content.multi([prompt, ...videoPart])
]);
print(response.text);

您可以呼叫 GenerateContentAsync() 來根據文字和影片檔案的多模態輸入內容生成文字。


using Firebase;
using Firebase.AI;

// Initialize the Gemini Developer API backend service
var ai = FirebaseAI.GetInstance(FirebaseAI.Backend.GoogleAI());

// Create a `GenerativeModel` instance with a model that supports your use case
var model = ai.GetGenerativeModel(modelName: "gemini-2.0-flash");


// Provide the video as `data` with the appropriate MIME type.
var video = ModelContent.InlineData("video/mp4",
      System.IO.File.ReadAllBytes(System.IO.Path.Combine(
          UnityEngine.Application.streamingAssetsPath, "yourVideo.mp4")));

// Provide a text prompt to include with the video
var prompt = ModelContent.Text("What is in the video?");

// To generate text output, call GenerateContentAsync with the text and video
var response = await model.GenerateContentAsync(new [] { video, prompt });
UnityEngine.Debug.Log(response.Text ?? "No text in response.");

瞭解如何選擇適合用途和應用程式的模型。