SpannableString实现带圆角标签效果

• 参考一：Android——SpannableString实现带圆角标签效果

• 参考二：Android——SpannableString字体大小不一致垂直居中

• 参考三：[Android]自定义ReplacementSpan实现带背景色的圆角SPAN

• 以下是自己的一点思考和理解

  1. 一个需要绘制文字的背景添加圆角
  2. 需要绘制文字垂直的位置和两边的位置 ReplacementSpan 的 draw 方法返回的就是文字的基线。
  3. 同时需要注意的是绘制文字的时候，设置画笔的大小

public class RoundBackgroundColorSpan extends ReplacementSpan {

    private int fontSize;
    private int margin;
    private int radius;
    private int textColor;
    private int bgColor;
    private int mSize;

    public static final int STYLE_FILL = 0;//填充
    public static final int STYLE_STROCK = 1;//扫边。扫边颜色默认和字体颜色一致
    private int mStyle;

    public RoundBackgroundColorSpan(int fontSize, int margin, int radius, int textColor, int bgColor) {
        this(fontSize, margin, radius, textColor, bgColor, STYLE_FILL);
    }

    public RoundBackgroundColorSpan(int fontSize, int margin, int radius, int textColor, int bgColor, int style) {
        this.fontSize = fontSize;
        this.margin = margin;
        this.radius = radius;
        this.textColor = textColor;
        this.bgColor = bgColor;
        this.mStyle = style;
    }

    @Override
    public int getSize(@NonNull Paint paint, CharSequence text, int start, int end, @Nullable Paint.FontMetricsInt fm) {
        Paint newPaint = getCustomTextPaint(paint);
        mSize = (int) newPaint.measureText(text, start, end) + margin * 2;
        return mSize;
    }

    @Override
    public void draw(@NonNull Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int
        bottom, @NonNull Paint paint) {
        Paint newPaint = getCustomTextPaint(paint);

        RectF rect = new RectF(x, y + paint.ascent(), x + mSize, y + paint.descent());
        // 设置背景矩形，x为文字左边缘的x值，y为文字的baseline的y值。
        // paint.ascent()获得baseline到文字上边缘的值，
        // paint.descent()获得baseline到文字下边缘
        if (mStyle == STYLE_STROCK) {
            paint.setColor(textColor);
            paint.setStyle(Paint.Style.STROKE);
        } else {
            paint.setColor(bgColor);
            paint.setStyle(Paint.Style.FILL);
        }
        canvas.drawRoundRect(rect, radius, radius, paint);

        // 绘制字
        newPaint.setAntiAlias(true);
        newPaint.setColor(textColor);
        // 获取文字的宽度
        int textWidth = (int) newPaint.measureText(text, start, end);
        // 获取文字左边的偏移量
        int offsetX = (int) ((rect.right - rect.left - textWidth) / 2);
        canvas.drawText(text, start, end, x + offsetX, y, newPaint);

    }

    private TextPaint getCustomTextPaint(Paint srcPaint) {
        TextPaint textPaint = new TextPaint(srcPaint);
        textPaint.setTextSize(sp2px(fontSize));
        return textPaint;
    }

    private int sp2px(int sp) {
        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,
            sp,
            MovieApplication.getApp().getResources().getDisplayMetrics());
    }
}

• 代码中调用的方式

int radiusColor2 = getResources().getColor(R.color.colorAccent);
int radiusColor22 = getResources().getColor(R.color.pink);
String content2 = getString(R.string.content1);
SpannableString spanString2 = new SpannableString(content2);
int start2 = content2.indexOf("录了本");
int end2 = start2 + "录了本".length();
spanString2.setSpan(new RadiusBackgroundSpan(11, 80, 10, radiusColor22, radiusColor2, STYLE_STROCK),
start2, end2, Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
tvDest11111111.append(spanString2); // setText 都可以