Libgdx外部存储导致的NullPointerException在Android [英] Libgdx external storage causes NullPointerException on Android

问题描述

我无法访问Android上的外部存储与GDX库。任何帮助将是AP preciated！

I'm having trouble accessing external storage on Android with the Gdx library. Any help would be appreciated!

简体code：

import android.app.Activity;
import android.os.Bundle;
import com.badlogic.gdx.Gdx;

public class Mp3AndFftTest extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Gdx.files.isExternalStorageAvailable();
    }
}

这会导致：

ERROR   AndroidRuntime  FATAL EXCEPTION: main
ERROR   AndroidRuntime  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.cmbryan.android/com.cmbryan.android.Mp3AndFftTest}: java.lang.NullPointerException
ERROR   AndroidRuntime      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
ERROR   AndroidRuntime      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
ERROR   AndroidRuntime      at android.app.ActivityThread.access$1500(ActivityThread.java:117)
ERROR   AndroidRuntime      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
ERROR   AndroidRuntime      at android.os.Handler.dispatchMessage(Handler.java:99)
ERROR   AndroidRuntime      at android.os.Looper.loop(Looper.java:123)
ERROR   AndroidRuntime      at android.app.ActivityThread.main(ActivityThread.java:3683)
ERROR   AndroidRuntime      at java.lang.reflect.Method.invokeNative(Native Method)
ERROR   AndroidRuntime      at java.lang.reflect.Method.invoke(Method.java:507)
ERROR   AndroidRuntime      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
ERROR   AndroidRuntime      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
ERROR   AndroidRuntime      at dalvik.system.NativeStart.main(Native Method)
ERROR   AndroidRuntime  Caused by: java.lang.NullPointerException
ERROR   AndroidRuntime      at com.cmbryan.android.Mp3AndFftTest.onCreate(Mp3AndFftTest.java:17)
ERROR   AndroidRuntime      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
ERROR   AndroidRuntime      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
ERROR   AndroidRuntime      ... 11 more

我在Android清单正确的权限，并在模拟器和实际设备进行测试。我在想什么？难道是因为我使用NetBeans，也许??

I have correct permissions in the Android manifest, and have tested on the emulator and a real device. What am I missing? Is it because I'm using netbeans, maybe??

推荐答案

17号线是：

Gdx.files.isExternalStorageAvailable();

吧？ Gdx.files 为空。这是因为你还没有运行GDX初始化code，它树立全局快捷键在 GDX 。您需要创建一个 ApplicationListener ，并把它传递给 AndroidApplication.initialize（..）。

right? Gdx.files is null. This is because you haven't run the GDX initialization code that sets up the global shortcuts in Gdx. You need to create an ApplicationListener and pass it to AndroidApplication.initialize(..).

请按照这里的例子： HTTP：//$c$c.google .COM / p / libgdx /维基/ ProjectSetup

libGDX的状态是不明确的，直到你完成了所有预期的初始化。 libGDX不仅仅是一个库更可以消耗件出来，其处理您的应用程序的完整安装和初始化了一个框架。

libGDX's state is ill-defined until you've completed all the expected initialization. libGDX is more than just a library you can consume pieces out of, its a framework that handles the complete setup and initialization of your app.

这篇关于Libgdx外部存储导致的NullPointerException在Android的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！