Android 2.3關於StrictMode使用是本文要介紹的內容,主要是來瞭解並學習Android 2.3的內容,具體關於Android 2.3內容的詳解來看本文。
ANR視窗產生的原因是多種多樣的。程式的主線程因為IO讀寫或網路阻塞而導致被阻塞了,外部存放裝置被獨佔了或系統負荷load)過高即不是自己編寫的程式的問題,可能是系統或者其他第三方程式導致的問題),都有可能導致ANR視窗的出現。
從Android 2.3開始提供了一個新的類StrictMode,可以協助開發人員改進他們的Android開發應用,StrictMode可以用於捕捉髮生在應用程式
主線程中耗時的磁碟、網路訪問或函數調用,可以協助開發人員使其改進程式,使主線程處理UI和動畫在磁碟讀寫和網路操作時變得更平滑,避免主線程被阻塞,導致ANR視窗的發生。
下面簡要說明下Android 2.3新特性StrictMode限制模式的工作方式,見下面的代碼:
- public void onCreate() {
- if (DEVELOPER_MODE) {
- StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
- .detectDiskReads()
- .detectDiskWrites()
- .detectNetwork() // 這裡可以替換為detectAll() 就包括了磁碟讀寫和網路I/O
- .penaltyLog() //列印logcat,當然也可以定位到dropbox,通過檔案儲存相應的log
- .build());
- StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
- .detectLeakedSqlLiteObjects() //探測SQLite資料庫操作
- .penaltyLog() //列印logcat
- .penaltyDeath()
- .build());
- }
- super.onCreate();
上述代碼可以在Application的OnCreate中添加,這樣就能在程式啟動的最初一刻進行監控了。
輸出log如下:
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): StrictMode policy violation; ~duration=696 ms:
- android.os.StrictMode$StrictModeDiskReadViolation: policy=23 violation=2
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at android.os.StrictMode$AndroidBlockGuardPolicy.onReadFromDisk(StrictMode.java:745)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at dalvik.system.BlockGuard$WrappedFileSystem.open(BlockGuard.java:228)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at java.io.FileOutputStream.<init>(FileOutputStream.java:94)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at java.io.FileOutputStream.<init>(FileOutputStream.java:66)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at java.io.FileWriter.<init>(FileWriter.java:42)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at org.zelos.asm.main.writeFile(main.java:30)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at org.zelos.asm.main.onCreate(main.java:19)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at android.os.Handler.dispatchMessage(Handler.java:99)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at android.os.Looper.loop(Looper.java:123)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at android.app.ActivityThread.main(ActivityThread.java:3683)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at java.lang.reflect.Method.invokeNative(Native Method)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at java.lang.reflect.Method.invoke(Method.java:507)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
- 02-27 10:03:56.122: DEBUG/StrictMode(16210): at dalvik.system.NativeStart.main(Native Method)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): StrictMode policy violation; ~duration=619 ms:
- android.os.StrictMode$StrictModeDiskWriteViolation: policy=23 violation=1
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at android.os.StrictMode$AndroidBlockGuardPolicy.onWriteToDisk(StrictMode.java:732)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at dalvik.system.BlockGuard$WrappedFileSystem.open(BlockGuard.java:230)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at java.io.FileOutputStream.<init>(FileOutputStream.java:94)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at java.io.FileOutputStream.<init>(FileOutputStream.java:66)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at java.io.FileWriter.<init>(FileWriter.java:42)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at org.zelos.asm.main.writeFile(main.java:30)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at org.zelos.asm.main.onCreate(main.java:19)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at android.os.Handler.dispatchMessage(Handler.java:99)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at android.os.Looper.loop(Looper.java:123)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at android.app.ActivityThread.main(ActivityThread.java:3683)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at java.lang.reflect.Method.invokeNative(Native Method)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at java.lang.reflect.Method.invoke(Method.java:507)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
- 02-27 10:03:56.162: DEBUG/StrictMode(16210): at dalvik.system.NativeStart.main(Native Method)
小結:Android 2.3關於StrictMode使用教程的內容介紹完了,希望通過Android 2.3內容的學習能對你有所協助。更多想要瞭解關於Android 2.3更多的內容,請參考編輯精選。