AssetManager仍然需要未來的功能嗎？

Question

何時創建和關閉AssetManager實例。

我的程序中有一個錯誤。該DDMS是說....

07-04 18:44:59.241: DEBUG/KeyguardViewMediator(65): pokeWakelock(5000) 
07-04 18:44:59.541: DEBUG/KeyguardViewMediator(65): pokeWakelock(5000) 
07-04 18:45:00.101: INFO/ARMAssembler(65): generated scanline__00000077:03545404_00000004_00000000 [ 47 ipp] (67 ins) at [0x33b540:0x33b64c] in 9815520 ns 
07-04 18:45:00.281: INFO/ARMAssembler(65): generated scanline__00000177:03515104_00001001_00000000 [ 91 ipp] (114 ins) at [0x33c088:0x33c250] in 2206721 ns 
07-04 18:45:00.561: WARN/ActivityManager(65): finishReceiver called but no pending broadcasts 
07-04 18:45:10.843: DEBUG/AndroidRuntime(277): Shutting down VM 
07-04 18:45:10.843: WARN/dalvikvm(277): threadid=1: thread exiting with uncaught exception (group=0x4001d800) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277): FATAL EXCEPTION: main 
07-04 18:45:11.191: ERROR/AndroidRuntime(277): android.content.res.Resources$NotFoundException: File res/layout/simple_spinner_item.xml from xml type layout resource ID #0x1090008 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.content.res.Resources.loadXmlResourceParser(Resources.java:1916) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.content.res.Resources.loadXmlResourceParser(Resources.java:1871) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.content.res.Resources.getLayout(Resources.java:731) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.LayoutInflater.inflate(LayoutInflater.java:318) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:332) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.ArrayAdapter.getView(ArrayAdapter.java:323) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.AbsSpinner.onMeasure(AbsSpinner.java:192) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.View.measure(View.java:8171) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.TableRow.getColumnsWidths(TableRow.java:308) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.TableLayout.findLargestCells(TableLayout.java:497) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.TableLayout.measureVertical(TableLayout.java:462) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.TableLayout.onMeasure(TableLayout.java:428) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.View.measure(View.java:8171) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3132) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1012) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.LinearLayout.measureVertical(LinearLayout.java:381) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.LinearLayout.onMeasure(LinearLayout.java:304) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.View.measure(View.java:8171) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3132) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:245) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.View.measure(View.java:8171) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.LinearLayout.measureVertical(LinearLayout.java:526) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.LinearLayout.onMeasure(LinearLayout.java:304) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.View.measure(View.java:8171) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3132) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:245) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.View.measure(View.java:8171) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.ViewRoot.performTraversals(ViewRoot.java:801) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1727) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.os.Handler.dispatchMessage(Handler.java:99) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.os.Looper.loop(Looper.java:123) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.app.ActivityThread.main(ActivityThread.java:4627) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at java.lang.reflect.Method.invokeNative(Native Method) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at java.lang.reflect.Method.invoke(Method.java:521) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at dalvik.system.NativeStart.main(Native Method) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277): Caused by: java.lang.RuntimeException: Assetmanager has been closed 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.content.res.AssetManager.openXmlBlockAsset(AssetManager.java:483) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  at android.content.res.Resources.loadXmlResourceParser(Resources.java:1898) 
07-04 18:45:11.191: ERROR/AndroidRuntime(277):  ... 36 more 

我不會發布我的所有代碼，因爲它是很長，但我的方案的結構與此類似....

public class myAppActivity extends Activity { 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     usesAnInstanceOfAssetManager(); 
     addsTextToASpinner(); 
    } 


    private void usesAnInstanceOfAssetManager() { 
     AssetManager assetManager = getAssets(); 
     ///blah blah blah..... 
     assetManager.close(); 
     return; 
    } 

    public void addsTextToASpinner(){ 
     // code to add text fields to a spinner 
     // executing this function caused the error shown above 
     return; 
    } 
} 

我注意到了行：

07-04 18：45：11.191：ERROR/AndroidRuntime（277）：了java.lang.RuntimeException：致Assetmanager已經關閉

所以，問題似乎是，第一函數「 usesAnInstanceOfAs setManager「關閉資產管理器，第二個函數需要assetManager。我在函數「usesAnInstanceOfAssetManager」中註釋掉了assetManager.close（）行，我的應用程序沒有崩潰。所以我的問題是......

什麼是使用AssetManager的最佳實踐？每個程序只能使用一次嗎？我雖然通過聲明它的一個實例並在完成時關閉它是適當的行爲，但似乎並非如此。 AssetManager是「靜態」的嗎？我是否總是需要它？

Answer 1

您可以在我假設的名爲AddTextToSpinner（）的Activity之後關閉AssetManager。 如果您還需要其他地方，只需再次打開。

如果您需要更多信息有關AssetManager你應該訪問此鏈接： http://developer.android.com/reference/android/content/res/AssetManager.html

我用我的AssetManager的方法是如下：

我打電話給我的parseXMLFile（）， 在那裏我打開我的AssetManager， 我打開我的XML文件，讀取並存儲數據到對象中， 關閉AssetManager。

這樣我就可以使用AssetManager一次，而在以後的應用程序中，我可以只使用這些對象。

我希望這是你正在尋找的答案！

Answer 2

到目前爲止我可以看到，AssetManager是由系統創建的，不需要打開或關閉AssertManager。

應用程序需要做的是打開/關閉它使用的inputStream。 糾正我，如果我錯了。