从资产文件夹获取getResources（）。getAssets（）字体返回NullPointerException

Question

我试图从＆＃34; assets \ font＆＃34;加载自定义字体文件夹

这是我的＆＃34; TypefaceSingelton ＆＃34;班级代码：

    public class TypefaceSingelton {

        private static TypefaceSingelton instance = new TypefaceSingelton();

        private TypefaceSingelton() {}

        public static TypefaceSingelton getInstance() {
            return instance;
        }
        public static  Typeface getFont() {
            return Typeface.createFromAsset(AppContext.getAppContext().
            getResources().getAssets(), "fonts/Myfont.otf");
        }
    }

和我的＆＃34; AppContext ＆＃34; class：

public class AppContext extends Application {

    public static Context context;
    @Override   
    public void onCreate(){

        super.onCreate();
        AppContext.context = getApplicationContext();
    }
    public static Context getAppContext() {
        return AppContext.context;
    }

}

以及我如何在MainActivity中使用它：

public class MainActivity extends Activity {

    private final Typeface FontTF = TypefaceSingelton.getFont();

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        final AutoCompleteTextView CtextView = (AutoCompleteTextView) findViewById(R.id.autoComplete);
        CtextView.setTypeface(FontTF);

它在＆＃34; Typeface.createFromAsset＆＃34;中给出了异常。在TypefaceSingelton里面：

08-16 07:55:51.834: E/AndroidRuntime(3109):     Caused by: java.lang.NullPointerException
08-16 07:55:51.834: E/AndroidRuntime(3109):     at com.test.TypefaceSingelton.getFont(TypefaceSingelton.java:20)
08-16 07:55:51.834: E/AndroidRuntime(3109):     at com.test.MainActivity.onCreate(MainActivity.java:133)
08-16 07:55:51.834: E/AndroidRuntime(3109):     at android.app.Activity.performCreate(Activity.java:5104)
08-16 07:55:51.834: E/AndroidRuntime(3109):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)

即将使用＆＃34; TypefaceSingelton＆＃34;避免性能下降

除了该程序使用以下代码：

private final Typeface FontTF;
@Override
public void onCreate(Bundle savedInstanceState) {
    Typeface FontTF = TypefaceSingelton.getFont();