我想有Spannable，看起来像在IDE中的错误 - 强调与另一种颜色

I'd like to have Spannable that looks like error in IDEs - underline with another color.

我试图创建 Col​​orUnderlineSpan 类扩展了Android的 UnderlineSpan ，但它使所有的文字另一种颜色（我需要添加颜色的下划线只）：

I've tried to create ColorUnderlineSpan class that extends android UnderlineSpan, but it makes all the text another color (i need to add colored underline only):

/**
 * Underline Span with color
 */
public class ColorUnderlineSpan extends android.text.style.UnderlineSpan {

    private int underlineColor;

    public ColorUnderlineSpan(int underlineColor) {
        super();
        this.underlineColor = underlineColor;
    }

    @Override
    public void updateDrawState(TextPaint ds) {
        super.updateDrawState(ds);
        ds.setColor(underlineColor);
    }
}

我还发现 DynamicDrawableSpan 类，但我不能看到画布边界提请。

I've also found DynamicDrawableSpan class but i can't see canvas bounds to draw to.

这将是巨大的，得到任何Spannable实现了一套抽象的画法范围的说法。

It would be great to get any Spannable impl with abstract draw method with bounds argument.

推荐答案

这是不是prettiest解决方案，但它结束了为我工作：

This isn't the prettiest solution, but it ended up working for me:

public class CustomUnderlineSpan implements LineBackgroundSpan {

int color;
Paint p;
int start, end;
public CustomUnderlineSpan(int underlineColor, int underlineStart, int underlineEnd) {
    super();
    color = underlineColor;
    this.start = underlineStart;
    this.end = underlineEnd;
    p = new Paint();
    p.setColor(color);
    p.setStrokeWidth(3F);
    p.setStyle(Paint.Style.FILL_AND_STROKE);
}

@Override
public void drawBackground(Canvas c, Paint p, int left, int right, int top, int baseline, int bottom, CharSequence text, int start, int end, int lnum) {

    if (this.end < start) return;
    if (this.start > end) return;

    int offsetX = 0;
    if (this.start > start) {
        offsetX = (int)p.measureText(text.subSequence(start, this.start).toString());
    }

    int length = (int)p.measureText(text.subSequence(Math.max(start, this.start), Math.min(end, this.end)).toString());
    c.drawLine(offsetX, baseline + 3F, length + offsetX, baseline + 3F, this.p);
}

这很奇怪，因为你必须指定字符索引，开始和结束用下划线，但它为我工作。

It's weird because you have to specify the character index to start and end your underlining with, but it worked for me.