使用getResources()获取字体.getassets()从assets文件夹返回NullPointerExcep

Question

我试图从"assetsfont"文件夹加载自定义字体

这是我的"TypefaceSingelton"类代码:

    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"AppContext"类:

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;
    }

}

和我如何使用它在我的MainActivity:

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);

在"Typeface "处给出异常。

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)

我将使用"TypefaceSingelton"来避免性能下降

程序使用以下代码:

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

Answer 1

你试过吗?

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

Answer 2

注意Android不支持字体。font

为什么不使用一个自定义类TypefacedTextView来扩展AppCompatTextView，并为add type face属性创建styleable

public class TypefacedTextView extends AppCompatTextView {
public TypefacedTextView(Context context, AttributeSet attrs) {
    super(context, attrs);
    TypedArray styledAttrs = context.obtainStyledAttributes(attrs, R.styleable.TypefacedTextView);
    String fontName = styledAttrs.getString(R.styleable.TypefacedTextView_typeface);
    setTypeFace(fontName);
    styledAttrs.recycle();
}
public void setTypeFace(String fontName){
    try{
        Typeface typeface = Typeface.createFromAsset(getContext().getAssets(), "fonts/" + fontName);
        setTypeface(typeface);
    }catch (Exception e){
    }
}

和这样的样式

 <declare-styleable name="TypefacedTextView">
    <attr name="typeface" format="string" />
</declare-styleable>

在目录res/values