Change the color of the underline in android

Question

I am developing the android application. I need to underline some of the Textview.

SpannableString content = new SpannableString("Ack:");
content.setSpan(new UnderlineSpan(), 0, content.length(), 0);
tvAck.setText(content);` 

I have used the above code for that. But now i want to change the color of the underline. Can any one tell me how to do so. Any help or suggestion is accepted.

Answer 1

There is no documented method to set the underline color. However, there is an undocumented TextPaint.setUnderline(int, float) method which allows you do provide the underline color and thickness:

final class ColoredUnderlineSpan extends CharacterStyle 
                                 implements UpdateAppearance {
    private final int mColor;

    public ColoredUnderlineSpan(final int color) {
        mColor = color;
    }

    @Override
    public void updateDrawState(final TextPaint tp) {
        try {
            final Method method = TextPaint.class.getMethod("setUnderlineText",
                                                            Integer.TYPE,
                                                            Float.TYPE);
            method.invoke(tp, mColor, 1.0f);
        } catch (final Exception e) {
            tp.setUnderlineText(true);
        }
    }
}