ClickableSpan

• ClickableSpan要生效，需要给textview设置MovementMethod，否则点击是不生效的。在texview的setMovementMethod方法里面，会赋值给mMovement变量，在textview的ontouchevent方法里面有如下判断：

if ((mMovement != null || onCheckIsTextEditor()) && isEnabled()
                && mText instanceof Spannable && mLayout != null) {
            boolean handled = false;
            if (mMovement != null) {
                handled |= mMovement.onTouchEvent(this, (Spannable) mText, event);
            }
            final boolean textIsSelectable = isTextSelectable();
            //这里一般来说不会走，因为mAutoLinkMask 默认是0，一般也不会去设值
            if (touchIsFinished && mLinksClickable && mAutoLinkMask != 0 && textIsSelectable) {
                ClickableSpan[] links = ((Spannable) mText).getSpans(getSelectionStart(),
                    getSelectionEnd(), ClickableSpan.class);
                if (links.length > 0) {
                    links[0].onClick(this);
                    handled = true;
                }
            }
//、、、
}

如果没设置，不会回调mMovement.onTouchEvent方法，也不会调用里面ClickableSpan的onClick方法，代码如下：

@Override
    public boolean onTouchEvent(TextView widget, Spannable buffer,
                                MotionEvent event) {
        int action = event.getAction();

        if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_DOWN) {
            int x = (int) event.getX();
            int y = (int) event.getY();

            x -= widget.getTotalPaddingLeft();
            y -= widget.getTotalPaddingTop();

            x += widget.getScrollX();
            y += widget.getScrollY();

            Layout layout = widget.getLayout();
            int line = layout.getLineForVertical(y);
            int off = layout.getOffsetForHorizontal(line, x);

            ClickableSpan[] links = buffer.getSpans(off, off, ClickableSpan.class);

            if (links.length != 0) {
                if (action == MotionEvent.ACTION_UP) {
                    links[0].onClick(widget);
                } else if (action == MotionEvent.ACTION_DOWN) {
                    Selection.setSelection(buffer,
                        buffer.getSpanStart(links[0]),
                        buffer.getSpanEnd(links[0]));
                }
                return true;
            } else {
                Selection.removeSelection(buffer);
            }
        }

        return super.onTouchEvent(widget, buffer, event);
    }

• ClickableSpan默认是有下划线的，而且点击后背景色不会变回来，要去掉下划线并实现点击后的背景恢复，需要重写ClickableSpan和LinkMovementMethod，实现如下：
  去下划线：

public abstract class MyClickable extends ClickableSpan {
    private int color;
    private boolean underline = false;
    public MyClickable(int color){
        this.color = color;
    }
    public MyClickable(boolean underline, int color){
        this.color = color;
        this.underline = underline;
    }
    @Override
    public void updateDrawState(TextPaint ds) {
        ds.setColor(color);//画笔颜色
        ds.setUnderlineText(underline);//是否有下划线
    }
}

背景恢复:

public class MyLInkMovementMethod extends LinkMovementMethod {
    private static MyLInkMovementMethod instance;

    public static MyLInkMovementMethod getInstance(){
        if(instance==null){
            instance = new MyLInkMovementMethod();
        }
        return instance;
    }

    @Override
    public boolean onTouchEvent(TextView widget, Spannable buffer, MotionEvent event) {
        int action = event.getAction();
        if (action == MotionEvent.ACTION_UP) {
            int x = (int) event.getX();
            int y = (int) event.getY();

            x -= widget.getTotalPaddingLeft();
            y -= widget.getTotalPaddingTop();

            x += widget.getScrollX();
            y += widget.getScrollY();

            Layout layout = widget.getLayout();
            int line = layout.getLineForVertical(y);
            int off = layout.getOffsetForHorizontal(line, x);

            ClickableSpan[] link = buffer.getSpans(off, off, ClickableSpan.class);
            if(link.length>0){
                link[0].onClick(widget);
                //在抬起的时候，重新设置span的背景色，这里也可以做其他操作，比如按下的颜色等等
                buffer.setSpan(new BackgroundColorSpan(Color.TRANSPARENT),
                        buffer.getSpanStart(link[0]), buffer.getSpanEnd(link[0]),
                        Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
                Selection.removeSelection(buffer);
                return true;
            }
        }
        return super.onTouchEvent(widget, buffer, event);
    }
}