供您参考，

 public class MyTextView extends TextView {

    public MyTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    public MyTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public MyTextView(Context context) {
        super(context);
        init();
    }

    public void init() {
        Typeface tf = Typeface.createFromAsset(getContext().getAssets(), "font/yourfont.ttf");
        setTypeface(tf ,1);

    }
}

在XML中，

 <you_package.MyTextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"       
        android:textSize="20sp"
        android:text="Your text"
        />