# v2.2 之後移除的已棄用 API > 在達到生命週期終點後，下列已棄用的 API 已從 Flutter 中移除。 ## 摘要 根據 Flutter 的 [棄用政策][Deprecation Policy]， 在 2.2 穩定版發佈後達到生命週期終點的 已棄用 API 已被移除。 所有受影響的 API 已彙整於此 主要來源，以協助遷移。 同時也提供了[快速參考表][quick reference sheet]。 [Deprecation Policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#deprecations [quick reference sheet]: /go/deprecations-removed-after-2-2 ## 變更內容 本節將依受影響的類別列出棄用項目。 ### `InputDecoration` 與 `InputDecorationTheme` 的 `hasFloatingPlaceholder` Flutter Fix 支援：是 `hasFloatingPlaceholder` 於 v1.13.2 被棄用。 請改用 `floatingLabelBehavior`。 當 `useFloatingPlaceholder` 為 true 時，請替換為 `FloatingLabelBehavior.auto`。 當 `useFloatingPlaceholder` 為 false 時，請替換為 `FloatingLabelBehavior.never`。 此變更允許指定更多行為，超越原本的二元選擇，並新增了 `FloatingLabelBehavior.always` 作為額外選項。 **遷移指南** 遷移前的程式碼： ```dart // InputDecoration // Base constructor InputDecoration(hasFloatingPlaceholder: true); InputDecoration(hasFloatingPlaceholder: false); // collapsed constructor InputDecoration.collapsed(hasFloatingPlaceholder: true); InputDecoration.collapsed(hasFloatingPlaceholder: false); // Field access inputDecoration.hasFloatingPlaceholder; // InputDecorationTheme // Base constructor InputDecorationTheme(hasFloatingPlaceholder: true); InputDecorationTheme(hasFloatingPlaceholder: false); // Field access inputDecorationTheme.hasFloatingPlaceholder; // copyWith inputDecorationTheme.copyWith(hasFloatingPlaceholder: false); inputDecorationTheme.copyWith(hasFloatingPlaceholder: true); ``` 遷移後的程式碼： ```dart // InputDecoration // Base constructor InputDecoration(floatingLabelBehavior: FloatingLabelBehavior.auto); InputDecoration(floatingLabelBehavior: FloatingLabelBehavior.never); // collapsed constructor InputDecoration.collapsed(floatingLabelBehavior: FloatingLabelBehavior.auto); InputDecoration.collapsed(floatingLabelBehavior: FloatingLabelBehavior.never); // Field access inputDecoration.floatingLabelBehavior; // InputDecorationTheme // Base constructor InputDecorationTheme(floatingLabelBehavior: FloatingLabelBehavior.auto); InputDecorationTheme(floatingLabelBehavior: FloatingLabelBehavior.never); // Field access inputDecorationTheme.floatingLabelBehavior; // copyWith inputDecorationTheme.copyWith(floatingLabelBehavior: FloatingLabelBehavior.never); inputDecorationTheme.copyWith(floatingLabelBehavior: FloatingLabelBehavior.auto); ``` **參考資料** API 文件： * [`InputDecoration`][`InputDecoration`] * [`InputDecorationTheme`][`InputDecorationTheme`] * [`FloatingLabelBehavior`][`FloatingLabelBehavior`] 相關議題： * [InputDecoration: option to always float label][InputDecoration: option to always float label] 相關 PR： * 已在 [#46115][#46115] 標記為已淘汰 * 已在 [#83923][#83923] 移除 [`InputDecoration`]: https://pub.dev/documentation/material_ui/latest/material_ui/InputDecoration-class.html [`InputDecorationTheme`]: https://pub.dev/documentation/material_ui/latest/material_ui/InputDecorationTheme-class.html [`FloatingLabelBehavior`]: https://pub.dev/documentation/material_ui/latest/material_ui/FloatingLabelBehavior-class.html [InputDecoration: option to always float label]: https://github.com/flutter/flutter/issues/30664 [#46115]: https://github.com/flutter/flutter/pull/46115 [#83923]: https://github.com/flutter/flutter/pull/83923 --- ### `TextTheme` Flutter Fix 支援：是 多個 `TextStyle` 的 `TextTheme` 屬性已於 v1.13.8 被標記為已淘汰。下表列出了這些屬性及其在新 API 中對應的替代項目。 | 已淘汰屬性 | 新 API | |---|---| | display4 | headline1 | | display3 | headline2 | | display2 | headline3 | | display1 | headline4 | | headline | headline5 | | title | headline6 | | subhead | subtitle1 | | body2 | bodyText1 | | body1 | bodyText2 | | subtitle | subtitle2 | **遷移指南** 遷移前的程式碼： ```dart // TextTheme // Base constructor TextTheme( display4: displayStyle4, display3: displayStyle3, display2: displayStyle2, display1: displayStyle1, headline: headlineStyle, title: titleStyle, subhead: subheadStyle, body2: body2Style, body1: body1Style, caption: captionStyle, button: buttonStyle, subtitle: subtitleStyle, overline: overlineStyle, ); // copyWith TextTheme.copyWith( display4: displayStyle4, display3: displayStyle3, display2: displayStyle2, display1: displayStyle1, headline: headlineStyle, title: titleStyle, subhead: subheadStyle, body2: body2Style, body1: body1Style, caption: captionStyle, button: buttonStyle, subtitle: subtitleStyle, overline: overlineStyle, ); // Getters TextStyle style; style = textTheme.display4; style = textTheme.display3; style = textTheme.display2; style = textTheme.display1; style = textTheme.headline; style = textTheme.title; style = textTheme.subhead; style = textTheme.body2; style = textTheme.body1; style = textTheme.caption; style = textTheme.button; style = textTheme.subtitle; style = textTheme.overline; ``` 遷移後的程式碼： ```dart // TextTheme // Base constructor TextTheme( headline1: displayStyle4, headline2: displayStyle3, headline3: displayStyle2, headline4: displayStyle1, headline5: headlineStyle, headline6: titleStyle, subtitle1: subheadStyle, bodyText1: body2Style, bodyText2: body1Style, caption: captionStyle, button: buttonStyle, subtitle2: subtitleStyle, overline: overlineStyle, ); TextTheme.copyWith( headline1: displayStyle4, headline2: displayStyle3, headline3: displayStyle2, headline4: displayStyle1, headline5: headlineStyle, headline6: titleStyle, subtitle1: subheadStyle, bodyText1: body2Style, bodyText2: body1Style, caption: captionStyle, button: buttonStyle, subtitle2: subtitleStyle, overline: overlineStyle, ); TextStyle style; style = textTheme.headline1; style = textTheme.headline2; style = textTheme.headline3; style = textTheme.headline4; style = textTheme.headline5; style = textTheme.headline6; style = textTheme.subtitle1; style = textTheme.bodyText1; style = textTheme.bodyText2; style = textTheme.caption; style = textTheme.button; style = textTheme.subtitle2; style = textTheme.overline; ``` **參考資料** 設計文件： * [Update the TextTheme API][Update the TextTheme API] API 文件： * [`TextTheme`][`TextTheme`] 相關議題： * [Migrate TextTheme to 2018 APIs][Migrate TextTheme to 2018 APIs] 相關 PR： * 在 [#48547][#48547] 標記為已淘汰 * 在 [#83924][#83924] 移除 [Update the TextTheme API]: /go/update-text-theme-api [`TextTheme`]: https://pub.dev/documentation/material_ui/latest/material_ui/TextTheme-class.html [Migrate TextTheme to 2018 APIs]: https://github.com/flutter/flutter/issues/45745 [#48547]: https://github.com/flutter/flutter/pull/48547 [#83924]: https://github.com/flutter/flutter/pull/83924 --- ### 預設 `Typography` Flutter Fix 是否支援：否 預設的 `Typography` 已於 v1.13.8 標記為已淘汰。 先前的預設值會回傳 2014 年 Material Design 規範的文字樣式。 現在將會導致 `TextStyle` 反映 2018 年 Material Design 規範的文字樣式。 若需使用舊版，請改用 `material2014` 建構子。 **遷移指南** 遷移前的程式碼： ```dart // Formerly returned 2014 TextStyle spec Typography(); ``` 遷移後的程式碼： ```dart // Use 2018 TextStyle spec, either by default or explicitly. Typography(); Typography.material2018(); // Use 2014 spec from former API Typography.material2014(); ``` **參考資料** 設計文件： * [Update the TextTheme API][Update the TextTheme API] API 文件： * [`Typography`][`Typography`] 相關議題： * [Migrate TextTheme to 2018 APIs][Migrate TextTheme to 2018 APIs] 相關 PR： * 在 [#48547][#48547] 標記為已棄用 * 在 [#83924][#83924] 移除 [Update the TextTheme API]: /go/update-text-theme-api [`Typography`]: https://pub.dev/documentation/material_ui/latest/material_ui/Typography-class.html [Migrate TextTheme to 2018 APIs]: https://github.com/flutter/flutter/issues/45745 [#48547]: https://github.com/flutter/flutter/pull/48547 [#83924]: https://github.com/flutter/flutter/pull/83924 --- ## 時程 在穩定版發行：2.5