您可以使用 ML Kit 辨識文字字串的語言。您可以取得字串最可能的語言,或是取得所有字串可用語言的可信度分數。
ML Kit 可辨識原生指令碼中 103 種不同語言的文字。此外,系統可辨識阿拉伯文、保加利亞文、中文、希臘文、北印度文、日文和俄文,
事前準備
- 如果您尚未將 Firebase 加入應用程式,請按照入門指南中的步驟進行。
- 在 Podfile 中加入 ML Kit 程式庫:
pod 'Firebase/MLNaturalLanguage', '6.25.0' pod 'Firebase/MLNLLanguageID', '6.25.0'
安裝或更新專案的 Pod 後,請務必使用.xcworkspace
開啟 Xcode 專案。 - 在應用程式中匯入 Firebase:
Swift
import Firebase
Objective-C
@import Firebase;
辨別字串的語言
如要識別字串的語言,請取得 LanguageIdentification
的執行個體,然後將字串傳遞至 identifyLanguage(for:)
方法。
例如:
Swift
let languageId = NaturalLanguage.naturalLanguage().languageIdentification()
languageId.identifyLanguage(for: text) { (languageCode, error) in
if let error = error {
print("Failed with error: \(error)")
return
}
if let languageCode = languageCode, languageCode != "und" {
print("Identified Language: \(languageCode)")
} else {
print("No language was identified")
}
}
Objective-C
FIRNaturalLanguage *naturalLanguage = [FIRNaturalLanguage naturalLanguage];
FIRLanguageIdentification *languageId = [naturalLanguage languageIdentification];
[languageId identifyLanguageForText:text
completion:^(NSString * _Nullable languageCode,
NSError * _Nullable error) {
if (error != nil) {
NSLog(@"Failed with error: %@", error.localizedDescription);
return;
}
if (languageCode != nil
&& ![languageCode isEqualToString:@"und"] ) {
NSLog(@"Identified Language: %@", languageCode);
} else {
NSLog(@"No language was identified");
}
}];
如果呼叫成功,系統會將 BCP-47 語言代碼傳遞至完成處理常式,指出文字的語言。查看支援語言的完整清單。如果沒有完全偵測出的語言,則會傳遞 und
(未確定) 程式碼。
根據預設,ML Kit 只有在識別可信度值至少為 0.5 的語言時,才會傳回非 und
值。如要變更這個門檻,請將 LanguageIdentificationOptions
物件傳遞至 languageIdentification(options:)
:
Swift
let options = LanguageIdentificationOptions(confidenceThreshold: 0.4)
let languageId = NaturalLanguage.naturalLanguage().languageIdentification(options: options)
Objective-C
FIRNaturalLanguage *naturalLanguage = [FIRNaturalLanguage naturalLanguage];
FIRLanguageIdentificationOptions *options =
[[FIRLanguageIdentificationOptions alloc] initWithConfidenceThreshold:0.4];
FIRLanguageIdentification *languageId =
[naturalLanguage languageIdentificationWithOptions:options];
取得字串的可能語言
如要針對字串最有可能使用的語言取得信心值,請取得 LanguageIdentification
的例項,然後將字串傳遞至 identifyPossibleLanguages(for:)
方法。
例如:
Swift
let languageId = NaturalLanguage.naturalLanguage().languageIdentification()
languageId.identifyPossibleLanguages(for: text) { (identifiedLanguages, error) in
if let error = error {
print("Failed with error: \(error)")
return
}
guard let identifiedLanguages = identifiedLanguages,
!identifiedLanguages.isEmpty,
identifiedLanguages[0].languageCode != "und"
else {
print("No language was identified")
return
}
print("Identified Languages:\n" +
identifiedLanguages.map {
String(format: "(%@, %.2f)", $0.languageCode, $0.confidence)
}.joined(separator: "\n"))
}
Objective-C
FIRNaturalLanguage *naturalLanguage = [FIRNaturalLanguage naturalLanguage];
FIRLanguageIdentification *languageId = [naturalLanguage languageIdentification];
[languageId identifyPossibleLanguagesForText:text
completion:^(NSArray<FIRIdentifiedLanguage *> * _Nonnull identifiedLanguages,
NSError * _Nullable error) {
if (error != nil) {
NSLog(@"Failed with error: %@", error.localizedDescription);
return;
}
if (identifiedLanguages.count == 1
&& [identifiedLanguages[0].languageCode isEqualToString:@"und"] ) {
NSLog(@"No language was identified");
return;
}
NSMutableString *outputText = [NSMutableString stringWithFormat:@"Identified Languages:"];
for (FIRIdentifiedLanguage *language in identifiedLanguages) {
[outputText appendFormat:@"\n(%@, %.2f)", language.languageCode, language.confidence];
}
NSLog(outputText);
}];
如果呼叫成功,系統會將 IdentifiedLanguage
物件清單傳遞至接續處理常式。透過每個物件,您可以取得語言的 BCP-47 程式碼,以及字串以該語言編寫的信心。查看支援語言的完整清單。請注意,這些值代表整個字串以指定語言表示,ML Kit 不會在單一字串中識別多種語言。
根據預設,ML Kit 只會傳回可信度值至少為 0.01 的語言。如要變更這個門檻,請將 LanguageIdentificationOptions
物件傳遞至 languageIdentification(options:)
:
Swift
let options = LanguageIdentificationOptions(confidenceThreshold: 0.4)
let languageId = NaturalLanguage.naturalLanguage().languageIdentification(options: options)
Objective-C
FIRNaturalLanguage *naturalLanguage = [FIRNaturalLanguage naturalLanguage];
FIRLanguageIdentificationOptions *options =
[[FIRLanguageIdentificationOptions alloc] initWithConfidenceThreshold:0.4];
FIRLanguageIdentification *languageId =
[naturalLanguage languageIdentificationWithOptions:options];
如果沒有語言符合此門檻,清單就會有一個項目,值為 und
。