未来的功能还需要AssetManager吗？

Question

我何时创建并关闭 AssetManager 实例。

我的程序中有一个错误。DDMS 说......

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

我不会发布我的所有代码，因为它真的很长，但我的程序的结构与此类似......

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;
    }
}

我注意到了这一行：

07-04 18：45：11.191：错误/AndroidRuntime（277）：引起：java.lang.RuntimeException：Assetmanager已关闭

所以问题似乎是第一个函数“usesAnInstanceOfAssetManager”正在关闭资产管理器，而第二个函数需要 assetManager。我注释掉了函数“usesAnInstanceOfAssetManager”中的 assetManager.close() 行，并且我的应用程序没有崩溃。所以我的问题是......

使用 AssetManager 的最佳实践是什么？每个程序只能使用一次吗？我虽然声明它的一个实例并在完成后关闭它是适当的操作过程，但情况似乎并非如此。AssetManager 是“静态的”吗？我总是需要它吗？

Answer 1

到目前为止我可以看到，AssetManager是系统创建的，不需要打开或关闭AssertManager。

应用程序需要做的是打开/关闭它使用的输入流。如我错了请纠正我。