java - 在自定义 Drawable 类中获取 Context

Question

我试图创建一个自定义类以将文本实现为可绘制的，但我无法将 Typeface 设置为 Paint。下面是自定义类(即 TextDrawable)的代码实现。

这里我想获取Application的上下文来调用方法getAssets()，但是这里我无法调用方法getContext()。

public class TextDrawable extends Drawable {
    private final String text;
    private final Paint paint;

    public TextDrawable(String text) {
        this.text = text;
        this.paint = new Paint();
        paint.setColor(Color.GRAY);
        paint.setTextSize(35f);
        //paint.setTypeface(Typeface.createFromAsset(**getContext().getAssets()**, "fonts/Montserrat-Regular.otf"));
        paint.setAntiAlias(true);
        paint.setTextAlign(Paint.Align.RIGHT);
    }

    @Override
    public void draw(Canvas canvas) {
        canvas.drawText(text, 0, 10, paint);
    }

    @Override
    public void setAlpha(int alpha) {
        paint.setAlpha(alpha);
    }

    @Override
    public void setColorFilter(ColorFilter cf) {
        paint.setColorFilter(cf);
    }

    @Override
    public int getOpacity() {
        return PixelFormat.TRANSLUCENT;
    }
}

Answer 1

I am not able to get getContext().getAssets() in this class.

您必须将 Context 对象作为参数传递给类的构造函数:

    public class TextDrawable extends Drawable {
        ...

        public TextDrawable(Context context, String text) {
            paint.setTypeface(Typeface.createFromAsset(context.getAssets(), "fonts/Montserrat-Regular.otf"));
            ...
        }
        ...
    }