txt.setText("這是一條測試文字");
        SpannableString clickString = new SpannableString("可點選文字");
        clickString.setSpan(new ClickableSpan() {
            @Override
            public void onClick(View widget) {
                startActivity(new Intent(MainActivity.this, FirstActivity.class));
            }

            @Override
            public void updateDrawState(TextPaint ds) {
                super.updateDrawState(ds);
                ds.setColor(Color.RED);//設定顏色
            }
        }, 0, clickString.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        txt.append(clickString);
        txt.append(new SpannableString("這也是一條測試文字"));
        SpannableString clickString2 = new SpannableString("我是可點選的");
        clickString2.setSpan(new ClickableSpan() {
            @Override
            public void onClick(View widget) {
                startActivity(new Intent(MainActivity.this, SecondActivity.class));
            }

            @Override
            public void updateDrawState(TextPaint ds) {
                super.updateDrawState(ds);
                ds.setColor(Color.BLUE); //設定顏色
            }
        }, 0, clickString2.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        txt.append(clickString2);
        txt.setMovementMethod(LinkMovementMethod.getInstance());//開始響應點選事件
 

不同大小文字新增背景且居中顯示

要實現的效果如下

想要實現上圖的效果首先想到的是先設定RelativeSizeSpan改變文字大小、再設定BackgroundColorSpan新增背景、再設定ForegroundColorSpan改變活動標籤文字大小

SpannableString spannableString = new SpannableString(" 活動標籤 " + "我是商品標題我是商品標題我是商品標題我是商品標題我是商品標題");
spannableString.setSpan(new RelativeSizeSpan(0.7f),0,6, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
spannableString.setSpan(new BackgroundColorSpan(Color.RED),0,6, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
spannableString.setSpan(new ForegroundColorSpan(Color.WHITE),0,6, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
tvSpan.setText(spannableString);
 

看下結果吧

發現活動標籤的文字沒有豎直居中，這裡就需要自定義了

/**
 * Created by cys on 2018/11/2 0002.
 * 根據大小繪製對應大小背景span
 */
public class BackgroundColorResizeSpan extends ReplacementSpan {
    private int mBackgroundColor;//字型背景色
    private float fontSizePx;//字型大小單位px
    private int mTextColor;//字型顏色
    private int mWidth;

    public BackgroundColorResizeSpan(int mBackgroundColor, int mTextColor, float fontSizePx) {
        this.mBackgroundColor = mBackgroundColor;
        this.mTextColor = mTextColor;
        this.fontSizePx = fontSizePx;
    }

    @Override
    public int getSize(@NonNull Paint paint, CharSequence text, int start, int end, @Nullable Paint.FontMetricsInt fm) {
        paint.setTextSize(fontSizePx);
        //獲取文字寬度
        mWidth = (int) paint.measureText(text.subSequence(start, end).toString());
        return mWidth;
    }

    @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.setTextSize(fontSizePx);
        Paint.FontMetrics fontMetrics = paint.getFontMetrics();
        paint.setColor(mBackgroundColor);
        //繪製背景
        canvas.drawRect(x, (bottom + top) / 2 - (fontMetrics.bottom - fontMetrics.top) / 2, mWidth, (bottom + top) / 2 + (fontMetrics.bottom - fontMetrics.top) / 2, paint);
        paint.setColor(mTextColor);
        //繪製文字
        canvas.drawText(text.subSequence(start, end).toString(), x, (top + bottom)/2 - (fontMetrics.bottom - fontMetrics.top) / 2 - fontMetrics.top, paint);

    }
}

 

使用起來也是比較方便的

SpannableString spannableString = new SpannableString(" 活動標籤 " + "我是商品標題我是商品標題我是商品標題我是商品標題我是商品標題");
spannableString.setSpan(new BackgroundColorResizeSpan(Color.RED, Color.WHITE, spToPx(11)), 0, 6, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
tvSpan.setText(spannableString);