为 TextView 的一部分设置不同的字体和颜色

Question

我试过了：

String s = "Some big string"
SpannableStringBuilder sb = new SpannableStringBuilder(s);
//normal font for 1st 9 chars
sb.setSpan(robotoRegular, 0,9,Spannable.SPAN_INCLUSIVE_INCLUSIVE);
//bold font for rest of the chars
sb.setSpan(robotoBold, 9,s.length(),Spannable.SPAN_INCLUSIVE_INCLUSIVE);
//also change color for rest of the chars
sb.setSpan(new ForegroundColorSpan(Color.BLACK), 9,s.length(),Spannable.SPAN_INCLUSIVE_INCLUSIVE);
textView.setText(sb);

但这没有用。

它只需要最新的setSpan，即..，文本颜色正在改变，而不是字体。

Answer 1

您必须使用TypefaceSpan 而不是Typeface。

但由于您使用的是自定义字体，因此您需要扩展 TypefaceSpan。

查看这个answer 并创建CustomTypefaceSpan 类。

现在执行以下操作：

Typeface robotoRegular = Typeface.createFromAsset(getAssets(), "fonts/Roboto-Regular.ttf");
Typeface robotoBold = Typeface.createFromAsset(getAssets(), "fonts/Roboto-Bold.ttf");

TypefaceSpan robotoRegularSpan = new CustomTypefaceSpan("", robotoRegular);
TypefaceSpan robotoBoldSpan = new CustomTypefaceSpan("", robotoBold);

// normal font for 1st 9 chars
sb.setSpan(robotoRegularSpan, 0, 9, Spannable.SPAN_INCLUSIVE_INCLUSIVE);
// bold font for rest of the chars
sb.setSpan(robotoBoldSpan, 9, s.length(), Spannable.SPAN_INCLUSIVE_INCLUSIVE);
// also change color for rest of the chars
sb.setSpan(new ForegroundColorSpan(Color.BLUE), 9, s.length(), Spannable.SPAN_INCLUSIVE_INCLUSIVE);
textView.setText(sb);

Answer 2

对于喜欢为此创建 utils 类的人：

public static SpannableStringBuilder makeTextBold (Activity activity, String string, int fromCharIndex, int toCharIndex) {
    return makeTextBold(activity, new SpannableStringBuilder(string), fromCharIndex, toCharIndex);
}

public static SpannableStringBuilder makeTextBold (Activity activity, SpannableStringBuilder string, int fromCharIndex, int toCharIndex) {
    SpannableStringBuilder sb = new SpannableStringBuilder(string);
    Typeface bold = Typeface.createFromAsset(activity.getAssets(), "fonts/NexaBold.ttf");
    TypefaceSpan robotoBoldSpan = new CustomTypefaceSpan("", bold);
    sb.setSpan(robotoBoldSpan, fromCharIndex, toCharIndex, Spannable.SPAN_INCLUSIVE_INCLUSIVE);
    return sb;
}

public static SpannableStringBuilder colorText (int resourceId, String string, Activity activity, int fromCharIndex, int toCharIndex) {
    return colorText(resourceId, new SpannableStringBuilder(string), activity, fromCharIndex, toCharIndex);
}

public static SpannableStringBuilder colorText (int resourceId, SpannableStringBuilder sb, Activity activity, int fromCharIndex, int toCharIndex) {
    sb.setSpan(new ForegroundColorSpan(activity.getResources().getColor(resourceId)), fromCharIndex, toCharIndex, Spannable.SPAN_INCLUSIVE_INCLUSIVE);
    return sb;
}

Answer 3

检查此代码：-

protected void onDraw(Canvas canvas) {

        Paint circlePaint = new Paint();
        Typeface mType = Typeface.create(Typeface.SANS_SERIF, Typeface.ITALIC);
        circlePaint.setTextSize(25);
        circlePaint.setColor(Color.RED);
        circlePaint.setTypeface(mType);
        canvas.drawText("Default Typeface", 50, 100, circlePaint);
        //
        circlePaint.setFlags(Paint.UNDERLINE_TEXT_FLAG);
        circlePaint.setColor(Color.YELLOW);
        canvas.drawText("Underline Text Flag", 50, 120, circlePaint);
        //
        circlePaint.setFlags(Paint.STRIKE_THRU_TEXT_FLAG);
        circlePaint.setColor(Color.GREEN);
        canvas.drawText("Strike Thru Text Flag", 50, 140, circlePaint);
        //
        circlePaint.setFlags(Paint.ANTI_ALIAS_FLAG);
        circlePaint.setColor(Color.WHITE);
        canvas.drawText("Anti Alias Flag", 50, 160, circlePaint);
        //
        circlePaint.setFlags(Paint.DEV_KERN_TEXT_FLAG);
        circlePaint.setColor(Color.WHITE);
        canvas.drawText("Dev Kern Text Flag", 50, 180, circlePaint);
        //
        circlePaint.setFlags(Paint.FAKE_BOLD_TEXT_FLAG);
        circlePaint.setColor(Color.CYAN);
        canvas.drawText("Fake Bold Text Flag", 50, 200, circlePaint);
    }

Answer 4

谷歌实际上在this video上给出了官方答复：

strings.xml

    <string name="test">Hello <annotation font="sans-serif-medium">World!</annotation></string>

在代码中：

val spannedString = getText(R.string.title) as SpannedString
val annotations = spannedString.getSpans(0, spannedString.length, Annotation::class.java)
for (annotation in annotations) {
    if (annotation.key == "font") {
        val fontName = annotation.value
        val typeFace: Typeface = ...
        spannable.setSpan(TypefaceSpan(typeFace), abstract.getSpanStart(annotation),
                abstract.getSpanEnd(annotation), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE)
    }
}

不过，这段代码遗漏了一些重要的事情：如何从字符串中获取字体（尤其是内置的），以及那里的“spannable”和“abstract”是什么。

如果有人知道如何正确获取这些内容并在此处填写空白，请告诉我。