在 Android 上使用 ML Kit 翻譯文字

你可以使用 ML Kit 翻譯不同語言的文字。機器學習套件 目前支援 59 種語言

事前準備

  1. 如果還沒試過 將 Firebase 新增至您的 Android 專案
  2. 將 ML Kit Android 程式庫的依附元件新增至模組 (應用程式層級) Gradle 檔案 (通常是 app/build.gradle):
    apply plugin: 'com.android.application'
    apply plugin: 'com.google.gms.google-services'
    
    dependencies {
      // ...
    
      implementation 'com.google.firebase:firebase-ml-natural-language:22.0.0'
      implementation 'com.google.firebase:firebase-ml-natural-language-translate-model:20.0.8'
    }
    

翻譯一段文字

如何在兩種語言之間翻譯字串:

  1. 建立 FirebaseTranslator 物件,使用來源設定該物件,並 指定語言:

    Java

    // Create an English-German translator:
    FirebaseTranslatorOptions options =
            new FirebaseTranslatorOptions.Builder()
                    .setSourceLanguage(FirebaseTranslateLanguage.EN)
                    .setTargetLanguage(FirebaseTranslateLanguage.DE)
                    .build();
    final FirebaseTranslator englishGermanTranslator =
            FirebaseNaturalLanguage.getInstance().getTranslator(options);
    

    Kotlin+KTX

    // Create an English-German translator:
    val options = FirebaseTranslatorOptions.Builder()
            .setSourceLanguage(FirebaseTranslateLanguage.EN)
            .setTargetLanguage(FirebaseTranslateLanguage.DE)
            .build()
    val englishGermanTranslator = FirebaseNaturalLanguage.getInstance().getTranslator(options)
    

    如果您不知道輸入文字的語言,可以使用 識別資訊 API。(但別忘了 而不是同時在裝置上保留太多語言模型)。

  2. 確認所需翻譯模型已下載到裝置。 確認模型可用前,請勿呼叫 translate()

    Java

    FirebaseModelDownloadConditions conditions = new FirebaseModelDownloadConditions.Builder()
        .requireWifi()
        .build();
    englishGermanTranslator.downloadModelIfNeeded(conditions)
          .addOnSuccessListener(
              new OnSuccessListener<Void>() {
                @Override
                public void onSuccess(Void v) {
                  // Model downloaded successfully. Okay to start translating.
                  // (Set a flag, unhide the translation UI, etc.)
                }
              })
          .addOnFailureListener(
              new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception e) {
                  // Model couldn’t be downloaded or other internal error.
                  // ...
                }
              });
    

    Kotlin+KTX

    englishGermanTranslator.downloadModelIfNeeded()
            .addOnSuccessListener {
                // Model downloaded successfully. Okay to start translating.
                // (Set a flag, unhide the translation UI, etc.)
            }
            .addOnFailureListener { exception ->
                // Model couldn’t be downloaded or other internal error.
                // ...
            }
    

    語言模型大約有 30 MB 的空間,因此不需要下載 除非使用者另有指定,否則只能透過 Wi-Fi 下載下載。個人中心 並刪除不需要的模型 請參閱「明確管理翻譯模型」。

  3. 確認下載模型後,請在 將原文語言轉換為 translate()

    Java

    englishGermanTranslator.translate(text)
          .addOnSuccessListener(
              new OnSuccessListener<String>() {
                @Override
                public void onSuccess(@NonNull String translatedText) {
                  // Translation successful.
                }
              })
          .addOnFailureListener(
              new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception e) {
                  // Error.
                  // ...
                }
              });
    

    Kotlin+KTX

    englishGermanTranslator.translate(text)
            .addOnSuccessListener { translatedText ->
                // Translation successful.
            }
            .addOnFailureListener { exception ->
                 // Error.
                 // ...
            }
    

    系統會以您設定的目標語言將譯文傳遞到 成功事件監聽器

明確管理翻譯模型

按照上述說明使用翻譯 API 時,ML Kit 會自動使用 視需要下載特定語言專屬的翻譯模型至裝置。個人中心 也可以明確管理 整合了 ML Kit 的翻譯模型管理 API可用的值包括 舉例來說,如果您想事先下載模型,或是刪除不需要的模型 登入裝置。

Java

FirebaseModelManager modelManager = FirebaseModelManager.getInstance();

// Get translation models stored on the device.
modelManager.getDownloadedModels(FirebaseTranslateRemoteModel.class)
        .addOnSuccessListener(new OnSuccessListener<Set<FirebaseTranslateRemoteModel>>() {
            @Override
            public void onSuccess(Set<FirebaseTranslateRemoteModel> models) {
                // ...
            }
        })
        .addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                // Error.
            }
        });

// Delete the German model if it's on the device.
FirebaseTranslateRemoteModel deModel =
        new FirebaseTranslateRemoteModel.Builder(FirebaseTranslateLanguage.DE).build();
modelManager.deleteDownloadedModel(deModel)
        .addOnSuccessListener(new OnSuccessListener<Void>() {
            @Override
            public void onSuccess(Void v) {
                // Model deleted.
            }
        })
        .addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                // Error.
            }
        });

// Download the French model.
FirebaseTranslateRemoteModel frModel =
        new FirebaseTranslateRemoteModel.Builder(FirebaseTranslateLanguage.FR).build();
FirebaseModelDownloadConditions conditions = new FirebaseModelDownloadConditions.Builder()
        .requireWifi()
        .build();
modelManager.download(frModel, conditions)
        .addOnSuccessListener(new OnSuccessListener<Void>() {
            @Override
            public void onSuccess(Void v) {
                // Model downloaded.
            }
        })
        .addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                // Error.
            }
        });

Kotlin+KTX

val modelManager = FirebaseModelManager.getInstance()

// Get translation models stored on the device.
modelManager.getDownloadedModels(FirebaseTranslateRemoteModel::class.java)
    .addOnSuccessListener { models ->
        // ...
    }
    .addOnFailureListener {
        // Error.
    }

// Delete the German model if it's on the device.
val deModel = FirebaseTranslateRemoteModel.Builder(FirebaseTranslateLanguage.DE).build()
modelManager.deleteDownloadedModel(deModel)
    .addOnSuccessListener {
        // Model deleted.
    }
    .addOnFailureListener {
        // Error.
    }

// Download the French model.
val frModel = FirebaseTranslateRemoteModel.Builder(FirebaseTranslateLanguage.FR).build()
val conditions = FirebaseModelDownloadConditions.Builder()
    .requireWifi()
    .build()
modelManager.download(frModel, conditions)
    .addOnSuccessListener {
        // Model downloaded.
    }
    .addOnFailureListener {
        // Error.
    }