從 Android Sample ApiDemos 中學習 android.animation API 的用法

時間 2019-12-08

標籤 android sample apidemos 學習 android.animation animation api 用法欄目 Android 简体版

原文原文鏈接

關於Android SDK Sample: ApiDemos

背景： HONEYCOMB 3.0 （about versions android-3.0 highlights）發佈於 2011.02，引入了New animation framework；3.1 發佈於 2011.05.html

在 Android 開發者網站搜索『animation』，經過『blog』過濾搜索結果，其中一篇文章 2011-02-24 Animation in Honeycomb 排在搜索結果第2位，可見其重要程度，做者是 Chet Haase，一個致力於圖形和動畫研究的 Android 開發者，能夠從他的我的博客graphics-geek.blogspot.com 閱讀更多相關主題的博文。java

『Animation in Honeycomb』討論了一個問題，已經有了能實現 move, scale, rotate, and fade 這些視圖動畫的 android.view.animation ，爲何還要在 3.0 引入新 APIs android.animation？新 APIs 帶來了哪些新特性？ 而後進一步展現了這些新特性的強大便利之處。android

其中有一段話是這樣的：git

But for a more detailed view of how things work, check out the API Demos in the SDK for the new animations. There are many small applications written for the new Animations category (at the top of the list of demos in the application, right before the word App. I like working on animation because it usually comes first in the alphabet).github

SDK samples 包含了一個例子 ApiDemos，這個例子詳盡地展現瞭如何使用 3.0 SDK API。其中一部分 demos 正是關於新的動畫機制（android.animation）。而和 animation 相關的 demos 排在整個列表的最前面，比 App demos 還靠前，這就是我爲何喜歡研究 animation 的緣由。api

（這個點可真奇特（簡（可）單（愛）），不知道這些牛人在想什麼，哈哈）app

從SDK sample 中獲取 ApiDemos

雖然是11年2月發佈的，而如今已是2016年的1月底了，雖然步子慢了五年，但3.x的動畫依然沒有過期，因此官方提供的 Sample 有什麼理由不去學習呢？（除此以外，你認爲有什麼捷徑嗎？）（感受像是發現了一直忽視的寶藏 ╰(￣▽￣)╮）ide

那麼接下來，就把它導入 studio，須要特別說明的是 ApiDemos 位於新的 SDK sample 的 legacy 目錄中，位於舊的sdk sample 根目錄中：學習

$HOME/Library/Android/sdk/samples/android-21/legacy/ApiDemos
$HOME/Library/Android/sdk/samples/android-15/ApiDemos

ApiDemos 和動畫有關的是（ApiDemos 所有列表見文章最後）：gradle

$ tree -L 2
.
├── animation
│   ├── ActivityTransition.java
│   ├── ActivityTransitionDetails.java
│   ├── AnimationCloning.java
│   ├── AnimationLoading.java
│   ├── AnimationSeeking.java
│   ├── AnimatorEvents.java
│   ├── BouncingBalls.javppa
│   ├── CustomEvaluator.pjava
│   ├── FixedGridLayout.java
│   ├── LayoutAnimations.java
│   ├── LayoutAnimationsByDefault.java
│   ├── LayoutAnimationsHideShow.java
│   ├── ListFlipper.java
│   ├── MultiPropertyAnimation.java
│   ├── PathAnimations.java
│   ├── ReversingAnimation.java
│   ├── Rotate3dAnimation.java
│   ├── ShapeHolder.java
│   ├── Transition3d.java
│   └── Transitions.java
├── app // 這就是 Chet 說的，animation 在 app 上....上...上..上.面  ╮(╯▽╰)╭
├── graphics
│   ├── AnimateDrawable.java
│   ├── AnimateDrawables.java
│   ├── Arcs.java
│   ├── ShadowCardDrag.java
│   ├── ShadowCardStack.java
│   ├── Sweep.java
└── view // 3D transition, Interpolators, Push, Shake
    ├── Animation1.java
    ├── Animation2.java
    ├── Animation3.java
    ├── LayoutAnimation1.java
    ├── LayoutAnimation2.java
    ├── LayoutAnimation3.java
    ├── LayoutAnimation4.java
    ├── LayoutAnimation5.java
    ├── LayoutAnimation6.java
    ├── LayoutAnimation7.java

導入 ApiDemos 到 Android Studio

經過 Android Studio 導入 ApiDemos 時遇到了以下幾個問題：

Plugin is too old, please update to a more recent version, or set ANDROID_DAILY_OVERRIDE environment variable to ...

作了以下修改（參照能夠正常運行的 Android Studio 項目）：
(1) 修改文件 gradle-wrapper.properties 中的 distributionUrl=https\://services.gradle.org/distributions/gradle-2.4-all.zip;（以前是2.8）
(2) 修改文件 build.gradle (Project: your_app_name) 中的 dependencies: classpath 'com.android.tools.build:gradle:1.3.0；（以前是2.0.0-alpha3）
點擊這裏查看詳細的解釋

Error:Execution failed for task ':app:mergeDebugResources'.
ApiDemos/app/src/main/res/xml/preference_switch: Error: The file name must end with .xml

看來官方 sample 也會出現一些低級錯誤，重命名這個文件加上後綴，能夠解決問題。

ApiDemos/app/src/main/java/com/example/android/apis/os/MmsMessagingDemo.java
Error:(19, 30) error: package com.google.android.mms does not exist

個人解決辦法很粗暴，直接刪掉 os 目錄，同時要刪掉在 manifest 中聲明的對應組件。

ApiDemos/app/src/main/java/com/example/android/apis/app/PrintBitmap.java
Error:(23, 32) error: package android.support.v4.print does not exist

須要導入 support-v4。針對 Studio 2.0 preview4 的導入方法：
File >> Project Structure... >> Modules >> Dependencies >> +1 Library dependency

Error:Execution failed for task ':app:processDebugManifest'.
Manifest merger failed : uses-sdk:minSdkVersion 1 cannot be smaller than version 4 declared in library [com.android.support:support-v4:23.1.1] /Users/weiyi/Develop/AndroidApp/OpenSourceDemo/ApiDemos/app/build/intermediates/exploded-aar/com.android.support/support-v4/23.1.1/AndroidManifest.xml
Suggestion: use tools:overrideLibrary="android.support.v4" to force usage

解決辦法是在 build.gradle (Module) 中增長 mindSdkVersion：

defaultConfig {
        minSdkVersion 21
    }

由於我是從android-21中導入的ApiDemos，因此項目中有些地方使用了5.0的API，因此把min設置爲21。

Error:(65, 40) error: cannot find symbol method sqrt(float)

FloatMath.sqrt(0.125f) 等方法已經從 6.0 SDK 中移除了：All methods were removed from the public API in version 23.
修改 compileSdkVersion 爲22（原來是23），同時修改 support-v4 的版本號爲 22.2.1

通過這幾步修改後，終於能夠在 Android Strudio 上編譯而後運行在 5.1 的系統上。
浪費了一天的時間 :(
寫這篇文檔又花了大半天 :)

因此，你若是想學習 ApiDemos，能夠按照上述步驟本身從 SDK sample 中導入。若是想避免這些修改過程，能夠clone我已經改好的：
Learning_Android_Open_Source/ApiDemos

附錄：ApiDemos 部分動畫截圖

附錄：ApiDemos 包含的所有示例

$ tree -L 2
.
├── ApiDemos.java
├── ApiDemosApplication.java
├── Shakespeare.java
├── accessibility
│   ├── ClockBackActivity.java
│   ├── ClockBackService.java
│   ├── CustomViewAccessibilityActivity.java
│   ├── TaskBackService.java
│   ├── TaskListActivity.java
│   └── TaskListView.java
├── animation
│   ├── ActivityTransition.java
│   ├── ActivityTransitionDetails.java
│   ├── AnimationCloning.java
│   ├── AnimationLoading.java
│   ├── AnimationSeeking.java
│   ├── AnimatorEvents.java
│   ├── BouncingBalls.java
│   ├── CustomEvaluator.java
│   ├── FixedGridLayout.java
│   ├── LayoutAnimations.java
│   ├── LayoutAnimationsByDefault.java
│   ├── LayoutAnimationsHideShow.java
│   ├── ListFlipper.java
│   ├── MultiPropertyAnimation.java
│   ├── PathAnimations.java
│   ├── ReversingAnimation.java
│   ├── Rotate3dAnimation.java
│   ├── ShapeHolder.java
│   ├── Transition3d.java
│   └── Transitions.java
├── app
│   ├── ActionBarDisplayOptions.java
│   ├── ActionBarMechanics.java
│   ├── ActionBarNavigation.java
│   ├── ActionBarNavigationTarget.java
│   ├── ActionBarSettingsActionProviderActivity.java
│   ├── ActionBarShareActionProviderActivity.java
│   ├── ActionBarTabs.java
│   ├── ActionBarUsage.java
│   ├── ActivityRecreate.java
│   ├── AlarmController.java
│   ├── AlarmService.java
│   ├── AlarmService_Service.java
│   ├── AlertDialogSamples.java
│   ├── Animation.java
│   ├── AppUpdateReceiver.java
│   ├── AppUpdateSspReceiver.java
│   ├── ContactsFilter.java
│   ├── ContactsFilterInstrumentation.java
│   ├── ContactsSelectInstrumentation.java
│   ├── CustomDialogActivity.java
│   ├── CustomTitle.java
│   ├── DeviceAdminSample.java
│   ├── DialogActivity.java
│   ├── DoNothing.java
│   ├── FinishAffinity.java
│   ├── ForegroundService.java
│   ├── ForwardTarget.java
│   ├── Forwarding.java
│   ├── FragmentAlertDialog.java
│   ├── FragmentArguments.java
│   ├── FragmentArgumentsFragment.java
│   ├── FragmentContextMenu.java
│   ├── FragmentCustomAnimations.java
│   ├── FragmentDialog.java
│   ├── FragmentDialogOrActivity.java
│   ├── FragmentHideShow.java
│   ├── FragmentLayout.java
│   ├── FragmentListArray.java
│   ├── FragmentMenu.java
│   ├── FragmentMenuFragment.java
│   ├── FragmentNestingTabs.java
│   ├── FragmentReceiveResult.java
│   ├── FragmentRetainInstance.java
│   ├── FragmentStack.java
│   ├── FragmentStackFragment.java
│   ├── FragmentTabs.java
│   ├── FragmentTabsFragment.java
│   ├── HelloWorld.java
│   ├── IncomingMessage.java
│   ├── IncomingMessageInterstitial.java
│   ├── IncomingMessageView.java
│   ├── IntentActivityFlags.java
│   ├── Intents.java
│   ├── IsolatedService.java
│   ├── IsolatedService2.java
│   ├── LauncherShortcuts.java
│   ├── LoaderCursor.java
│   ├── LoaderCustom.java
│   ├── LoaderRetained.java
│   ├── LoaderThrottle.java
│   ├── LocalSample.java
│   ├── LocalSampleInstrumentation.java
│   ├── LocalService.java
│   ├── LocalServiceActivities.java
│   ├── MenuInflateFromXml.java
│   ├── MessengerService.java
│   ├── MessengerServiceActivities.java
│   ├── NotificationDisplay.java
│   ├── NotifyWithText.java
│   ├── NotifyingController.java
│   ├── NotifyingService.java
│   ├── OneShotAlarm.java
│   ├── OverscanActivity.java
│   ├── PersistentState.java
│   ├── PresentationActivity.java
│   ├── PresentationWithMediaRouterActivity.java
│   ├── PrintBitmap.java
│   ├── PrintCustomContent.java
│   ├── PrintHtmlFromScreen.java
│   ├── PrintHtmlOffScreen.java
│   ├── QuickContactsDemo.java
│   ├── ReceiveResult.java
│   ├── RedirectEnter.java
│   ├── RedirectGetter.java
│   ├── RedirectMain.java
│   ├── RemoteService.java
│   ├── ReorderFour.java
│   ├── ReorderOnLaunch.java
│   ├── ReorderThree.java
│   ├── ReorderTwo.java
│   ├── RepeatingAlarm.java
│   ├── RotationAnimation.java
│   ├── SaveRestoreState.java
│   ├── ScreenOrientation.java
│   ├── SearchInvoke.java
│   ├── SearchQueryResults.java
│   ├── SearchSuggestionSampleProvider.java
│   ├── SecureDialogActivity.java
│   ├── SecureSurfaceViewActivity.java
│   ├── SecureWindowActivity.java
│   ├── SendResult.java
│   ├── ServiceStartArguments.java
│   ├── SetWallpaperActivity.java
│   ├── SoftInputModes.java
│   ├── StatusBarNotifications.java
│   ├── TextToSpeechActivity.java
│   ├── TranslucentActivity.java
│   ├── TranslucentBlurActivity.java
│   ├── VoiceRecognition.java
│   └── WallpaperActivity.java
├── appwidget
│   ├── ExampleAppWidgetConfigure.java
│   ├── ExampleAppWidgetProvider.java
│   └── ExampleBroadcastReceiver.java
├── content
│   ├── ChangedContacts.java
│   ├── ClipboardSample.java
│   ├── DocumentsSample.java
│   ├── ExternalStorage.java
│   ├── FileProvider.java
│   ├── InstallApk.java
│   ├── PickContact.java
│   ├── ReadAsset.java
│   ├── ResourcesLayoutReference.java
│   ├── ResourcesSample.java
│   ├── ResourcesSmallestWidth.java
│   ├── ResourcesWidthAndHeight.java
│   ├── StyledText.java
│   └── TextUndoActivity.java
├── graphics
│   ├── AlphaBitmap.java
│   ├── AnimateDrawable.java
│   ├── AnimateDrawables.java
│   ├── Arcs.java
│   ├── BitmapDecode.java
│   ├── BitmapMesh.java
│   ├── BitmapPixels.java
│   ├── CameraPreview.java
│   ├── Clipping.java
│   ├── ColorFilters.java
│   ├── ColorMatrixSample.java
│   ├── ColorPickerDialog.java
│   ├── Compass.java
│   ├── CompressedTextureActivity.java
│   ├── CreateBitmap.java
│   ├── Cube.java
│   ├── CubeMapActivity.java
│   ├── CubeRenderer.java
│   ├── DensityActivity.java
│   ├── DrawPoints.java
│   ├── FingerPaint.java
│   ├── FrameBufferObjectActivity.java
│   ├── GLES20Activity.java
│   ├── GLES20TriangleRenderer.java
│   ├── GLSurfaceViewActivity.java
│   ├── GradientDrawable1.java
│   ├── GraphicsActivity.java
│   ├── Layers.java
│   ├── MatrixPaletteActivity.java
│   ├── MatrixPaletteRenderer.java
│   ├── MeasureText.java
│   ├── PathEffects.java
│   ├── PathFillTypes.java
│   ├── Patterns.java
│   ├── PictureLayout.java
│   ├── Pictures.java
│   ├── PolyToPoly.java
│   ├── ProxyDrawable.java
│   ├── PurgeableBitmap.java
│   ├── PurgeableBitmapView.java
│   ├── Regions.java
│   ├── RoundRects.java
│   ├── ScaleToFit.java
│   ├── SensorTest.java
│   ├── ShadowCardDrag.java
│   ├── ShadowCardStack.java
│   ├── ShapeDrawable1.java
│   ├── StaticTriangleRenderer.java
│   ├── SurfaceViewOverlay.java
│   ├── Sweep.java
│   ├── TextAlign.java
│   ├── TouchPaint.java
│   ├── TouchRotateActivity.java
│   ├── TranslucentGLSurfaceViewActivity.java
│   ├── TriangleActivity.java
│   ├── TriangleRenderer.java
│   ├── Typefaces.java
│   ├── UnicodeChart.java
│   ├── Vertices.java
│   ├── WindowSurface.java
│   ├── Xfermodes.java
│   ├── kube
│   └── spritetext
├── hardware
│   └── ConsumerIr.java
├── media
│   ├── AudioFxDemo.java
│   ├── MediaPlayerDemo.java
│   ├── MediaPlayerDemo_Audio.java
│   ├── MediaPlayerDemo_Video.java
│   ├── VideoViewDemo.java
│   └── projection
├── nfc
│   ├── ForegroundDispatch.java
│   ├── ForegroundNdefPush.java
│   └── TechFilter.java
├── preference
│   ├── AdvancedPreferences.java
│   ├── DefaultValues.java
│   ├── FragmentPreferences.java
│   ├── LaunchingPreferences.java
│   ├── MyPreference.java
│   ├── PreferenceDependencies.java
│   ├── PreferenceWithHeaders.java
│   ├── PreferencesFromCode.java
│   ├── PreferencesFromXml.java
│   └── SwitchPreference.java
├── security
│   └── KeyStoreUsage.java
├── text
│   ├── Link.java
│   ├── LogTextBox.java
│   ├── LogTextBox1.java
│   └── Marquee.java
└── view
    ├── Animation1.java
    ├── Animation2.java
    ├── Animation3.java
    ├── AutoComplete1.java
    ├── AutoComplete2.java
    ├── AutoComplete3.java
    ├── AutoComplete4.java
    ├── AutoComplete5.java
    ├── AutoComplete6.java
    ├── Baseline1.java
    ├── Baseline2.java
    ├── Baseline3.java
    ├── Baseline4.java
    ├── Baseline6.java
    ├── Baseline7.java
    ├── BaselineNested1.java
    ├── BaselineNested2.java
    ├── BaselineNested3.java
    ├── Buttons1.java
    ├── CheckableFrameLayout.java
    ├── Cheeses.java
    ├── ChronometerDemo.java
    ├── ContentBrowserActivity.java
    ├── ContentBrowserNavActivity.java
    ├── Controls1.java
    ├── Controls2.java
    ├── Controls3.java
    ├── Controls4.java
    ├── Controls5.java
    ├── Controls6.java
    ├── Controls7.java
    ├── Controls8.java
    ├── Controls9.java
    ├── CustomLayout.java
    ├── CustomLayoutActivity.java
    ├── CustomView1.java
    ├── DateWidgets1.java
    ├── DateWidgets2.java
    ├── DragAndDropDemo.java
    ├── DraggableDot.java
    ├── ExpandableList1.java
    ├── ExpandableList2.java
    ├── ExpandableList3.java
    ├── Focus1.java
    ├── Focus2.java
    ├── Focus3.java
    ├── Focus5.java
    ├── GameActivity.java
    ├── GameControllerInput.java
    ├── GameView.java
    ├── Grid1.java
    ├── Grid2.java
    ├── Grid3.java
    ├── GridLayout1.java
    ├── GridLayout2.java
    ├── GridLayout3.java
    ├── HorizontalScrollView1.java
    ├── Hover.java
    ├── HoverInterceptorView.java
    ├── ImageButton1.java
    ├── ImageView1.java
    ├── InternalSelectionFocus.java
    ├── InternalSelectionScroll.java
    ├── InternalSelectionView.java
    ├── LabelView.java
    ├── LayoutAnimation1.java
    ├── LayoutAnimation2.java
    ├── LayoutAnimation3.java
    ├── LayoutAnimation4.java
    ├── LayoutAnimation5.java
    ├── LayoutAnimation6.java
    ├── LayoutAnimation7.java
    ├── LinearLayout1.java
    ├── LinearLayout10.java
    ├── LinearLayout2.java
    ├── LinearLayout3.java
    ├── LinearLayout4.java
    ├── LinearLayout5.java
    ├── LinearLayout6.java
    ├── LinearLayout7.java
    ├── LinearLayout8.java
    ├── LinearLayout9.java
    ├── List1.java
    ├── List10.java
    ├── List11.java
    ├── List12.java
    ├── List13.java
    ├── List14.java
    ├── List15.java
    ├── List16.java
    ├── List17.java
    ├── List2.java
    ├── List3.java
    ├── List4.java
    ├── List5.java
    ├── List6.java
    ├── List7.java
    ├── List8.java
    ├── List9.java
    ├── PopupMenu1.java
    ├── ProgressBar1.java
    ├── ProgressBar2.java
    ├── ProgressBar3.java
    ├── ProgressBar4.java
    ├── RadioGroup1.java
    ├── RatingBar1.java
    ├── RelativeLayout1.java
    ├── RelativeLayout2.java
    ├── RotatingButton.java
    ├── ScrollBar1.java
    ├── ScrollBar2.java
    ├── ScrollBar3.java
    ├── ScrollView1.java
    ├── ScrollView2.java
    ├── SearchViewActionBar.java
    ├── SearchViewAlwaysVisible.java
    ├── SearchViewFilterMode.java
    ├── SecureView.java
    ├── SecureViewOverlay.java
    ├── SeekBar1.java
    ├── Spinner1.java
    ├── SplitTouchView.java
    ├── Switches.java
    ├── SystemUIModes.java
    ├── SystemUIModesOverlay.java
    ├── TableLayout1.java
    ├── TableLayout10.java
    ├── TableLayout11.java
    ├── TableLayout12.java
    ├── TableLayout2.java
    ├── TableLayout3.java
    ├── TableLayout4.java
    ├── TableLayout5.java
    ├── TableLayout6.java
    ├── TableLayout7.java
    ├── TableLayout8.java
    ├── TableLayout9.java
    ├── Tabs1.java
    ├── Tabs2.java
    ├── Tabs3.java
    ├── Tabs4.java
    ├── Tabs5.java
    ├── Tabs6.java
    ├── TextClockDemo.java
    ├── TextSwitcher1.java
    ├── TranslucentBarsActivity.java
    ├── VideoPlayerActivity.java
    ├── Visibility1.java
    ├── WebView1.java
    └── WindowFocusObserver.java

16 directories, 391 files

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文章連接：http://li2.me/2016/01/android-sdk-sample...