Ionic 4.0.0-rc.0 釋出了，該版本的更新內容不多，主要是 bug 修復和引入新特性。

Bug Fixes

• action-sheet: set 100% height to fix scrollable options (#16789) (e3d7282)

• all: ts 3.2 issues (f393a82)

• angular: Fix cordova browser error when resumed (#16810) (e735d2c)

• angular: fix sibling router-outlets (

  #16774) (35e3848), closes #16411

• angular: router-outlet memory leak (2c41823), closes #16285

• body: body background matches ion-content (0699884)

• core: export ionic lifecycle names (77640c9), closes #16760

• core: ts lint issue (#16814) (fb38002)

• list: adjust label margin to align with spec for md (

  #16751) (60ef98d), closes #16643

• modal: --box-shadow (e2ee0b6), closes #16798

• progress-bar: looking nice inside toolbar (b5efede)

• pwa: use 100% of the viewport (4c4bdf2)

• tab-bar: adds selected color if tab bar is using a color (#16766) (54e5a24), closes #16761

• virtual-scroll:

   fixes dynamic changes (d1cecf1)

Features

• angular: expose animationDirection (#16802) (320eb03)

• angular: tabs.select() (56dd8ae), closes #16753

Performance Improvements

• angular: detach fromn change detection (f613b3b)