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.

score 14 · Answer 1 · answered Nov 08 '12 at 10:43

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);
        }
    }
}

I tried this and the invocation works but the underline color is still black. :( — Barry Fruitman, Jan 26 '13 at 02:42
Worked perfectly for me, as a note to others the 1.0f is the line thickness multiplier. A value of 1.0 means default thickness, 2.0 would be twice as thick. — Andrew Kelly, Aug 06 '14 at 01:24
It works, but the color and thickness are not restored from parcelable ( — Oleksandr Albul, Oct 13 '17 at 14:36

score 3 · Answer 2 · answered Oct 07 '11 at 08:17

I haven't tried this myself, so this is more an idea than a solution, but probably worth trying. Class UnderlineSpan has method updateDrawState, which takes TextPaint as a parameter. In turn, TextPain can has field public int linkColor.

So for you it would be something like

TextPaint tp = new TextPaint();
tp.linkColor = [your color];           //not quite sure what the format should be
UnderlineSpan us = new UnderlineSpan();
us.updateDrawState(tp);
SpannableString content = new SpannableString("Ack:");
content.setSpan(us, 0, content.length(), 0); tvAck.setText(content);

Reference for both TextPaint and UnderlineSpan are very poor, with majority of javadoc missing altogether (judge for yourself: http://developer.android.com/reference/android/text/TextPaint.html), so I'm not certain how to use these though.

I can't think of anything else. Why won't it work? Did you try it? — Aleks G, Oct 07 '11 at 08:34
The reason that this does not work is that `updateDrawState` only tells the `TextPaint` that it should be underlined. It does not affect the underline color. An `UnderlineSpan` just uses the text color for the underline color. The `linkColor` would change the color of the underline (and text) only for a `ClickableSpan` (or `URLSpan`). — Suragch, Oct 06 '17 at 06:49

score 1 · Answer 3 · answered Jun 26 '14 at 08:30

In TextPaint, there has a field 'underlineColor' and method 'setUnderlineText', indicated and can use to changed the underline color. But, they are '@hide' field and method, to use them, you must using reflecting, like this:

Field field = TextPaint.class.getDeclaredField("underlineColor");
field.setAccessible(true);
field.set(ds, mUnderlineColor);

ds is your TextPaint Object.

score 0 · Answer 4 · answered Aug 20 '20 at 07:47

0

Really late to encounter this scenrio. Here's another way, It would be to set multiple spans to the same spannable content:

SpannableString content = new SpannableString("Ack:");
content.setSpan(new UnderlineSpan(), 0, content.length(), 0);
content.setSpan(
        new ForegroundColorSpan(ContextCompat.getColor(context, R.color.red)),
        0,
        content.length(),
        0
);
tvAck.setText(content, TextView.BufferType.SPANNABLE);

answered Aug 20 '20 at 07:47

Abir Hasan Shawon

6,069
5
17
28

Its change text color with underline.... not just underline – Ucdemir Mar 30 '21 at 08:53

Change the color of the underline in android

4 Answers4

Linked