如何使用SpannableString更改行间距？

public class LineHeightSpanCustom implements LineHeightSpan {
    private int lineHeight;

    public LineHeightSpanCustom(int lineHeight) {
        this.lineHeight = lineHeight;
    }

    @Override
    public void chooseHeight(CharSequence text, int start, int end, int spanstartv, int v, Paint.FontMetricsInt fm) {
        fm.bottom += lineHeight;
        fm.descent += lineHeight;
    }
}

String text = "这是一段需要更改行间距的文本";
SpannableString spannableString = new SpannableString(text);
int lineHeight = 20; // 设置行间距的值，单位为像素
LineHeightSpanCustom lineHeightSpan = new LineHeightSpanCustom(lineHeight);
spannableString.setSpan(lineHeightSpan, 0, text.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);

textView.setText(spannableString);