以防有人使用数据绑定。我们可以像这样定义绑定适配器

@BindingAdapter("html")
fun setHtml(view: TextView, html: String) {
    view.setText(HtmlCompat.fromHtml(html, HtmlCompat.FROM_HTML_MODE_LEGACY))
}

然后我们可以在TextView上使用它

app:html="@{@string/bold_text}"

bold_text在哪里

<string name="bold_text"><![CDATA[Part of text is <b>bold</b>]]></string>

这是我的完整的解决方案，动态字符串值与大小写检查。

/**
 * Makes a portion of String formatted in BOLD.
 *
 * @param completeString       String from which a portion needs to be extracted and formatted.<br> eg. I am BOLD.
 * @param targetStringToFormat Target String value to format. <br>eg. BOLD
 * @param matchCase Match by target character case or not. If true, BOLD != bold
 * @return A string with a portion formatted in BOLD. <br> I am <b>BOLD</b>.
 */
public static SpannableStringBuilder formatAStringPortionInBold(String completeString, String targetStringToFormat, boolean matchCase) {
    //Null complete string return empty
    if (TextUtils.isEmpty(completeString)) {
        return new SpannableStringBuilder("");
    }

    SpannableStringBuilder str = new SpannableStringBuilder(completeString);
    int start_index = 0;

    //if matchCase is true, match exact string
    if (matchCase) {
        if (TextUtils.isEmpty(targetStringToFormat) || !completeString.contains(targetStringToFormat)) {
            return str;
        }

        start_index = str.toString().indexOf(targetStringToFormat);
    } else {
        //else find in lower cases
        if (TextUtils.isEmpty(targetStringToFormat) || !completeString.toLowerCase().contains(targetStringToFormat.toLowerCase())) {
            return str;
        }

        start_index = str.toString().toLowerCase().indexOf(targetStringToFormat.toLowerCase());
    }

    int end_index = start_index + targetStringToFormat.length();
    str.setSpan(new StyleSpan(BOLD), start_index, end_index, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    return str;
}

如。completeString = "I am BOLD"

情况下,我 if *targetStringToFormat* = "bold" and *matchCase* = true

返回“I am BOLD”(因为BOLD != BOLD)

案例二世 if *targetStringToFormat* = "bold" and *matchCase* = false

返回“I am BOLD”

应用:

myTextView.setText(formatAStringPortionInBold("I am BOLD", "bold", false))

希望有帮助!

您可以在构建器中分别添加这两个字符串，其中一个是spannedString，另一个是常规字符串。这样就不需要计算下标了。

val instructionPress = resources?.getString(R.string.settings_press)

val okText = resources?.getString(R.string.ok)
val spannableString = SpannableString(okText)

val spannableBuilder = SpannableStringBuilder()
spannableBuilder.append(instructionPress)
spannableBuilder.append(spannableString, StyleSpan(Typeface.BOLD), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE)

instructionText.setText(spannableBuilder,TextView.BufferType.SPANNABLE)

这是我使用的Kotlin扩展函数

/**
 * Sets the specified Typeface Style on the first instance of the specified substring(s)
 * @param one or more [Pair] of [String] and [Typeface] style (e.g. BOLD, ITALIC, etc.)
 */
fun TextView.setSubstringTypeface(vararg textsToStyle: Pair<String, Int>) {
    val spannableString = SpannableString(this.text)
    for (textToStyle in textsToStyle) {
        val startIndex = this.text.toString().indexOf(textToStyle.first)
        val endIndex = startIndex + textToStyle.first.length

        if (startIndex >= 0) {
            spannableString.setSpan(
                StyleSpan(textToStyle.second),
                startIndex,
                endIndex,
                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
            )
        }
    }
    this.setText(spannableString, TextView.BufferType.SPANNABLE)
}

用法:

text_view.text="something bold"
text_view.setSubstringTypeface(
    Pair(
        "something bold",
        Typeface.BOLD
    )
)

.

text_view.text="something bold something italic"
text_view.setSubstringTypeface(
    Pair(
        "something bold ",
        Typeface.BOLD
    ),
    Pair(
        "something italic",
        Typeface.ITALIC
    )
)

虽然你可以使用Html.fromHtml()，你可以使用一个更原生的方法是SpannableStringBuilder，这篇文章可能会有帮助。

SpannableStringBuilder str = new SpannableStringBuilder("Your awesome text");
str.setSpan(new android.text.style.StyleSpan(android.graphics.Typeface.BOLD), INT_START, INT_END, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
TextView tv=new TextView(context);
tv.setText(str);

我创建了一个静态方法来设置文本粗体的TextView和EditText部分

public static void boldPartOfText(View mView, String contentData, int startIndex, int endIndex){
        if(!contentData.isEmpty() && contentData.length() > endIndex) {
            final SpannableStringBuilder sb = new SpannableStringBuilder(contentData);

            final StyleSpan bss = new StyleSpan(Typeface.BOLD); // Span to make text bold
            final StyleSpan iss = new StyleSpan(Typeface.NORMAL); //Span to make text normal
            sb.setSpan(iss, 0, startIndex, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
            sb.setSpan(bss, startIndex, endIndex, Spannable.SPAN_INCLUSIVE_INCLUSIVE); // make first 4 characters Bold
            sb.setSpan(iss,endIndex, contentData.length()-1, Spanned.SPAN_INCLUSIVE_INCLUSIVE);

            if(mView instanceof TextView)
               ((TextView) mView).setText(sb);
            else if(mView instanceof EditText)
               ((EditText) mView).setText(sb);

        }
    }

另一个更定制的代码

  /*typeFaceStyle can be passed as 

    Typeface.NORMAL = 0;
    Typeface.BOLD = 1;
    Typeface.ITALIC = 2;
    Typeface.BOLD_ITALIC = 3;*/

    public static void boldPartOfText(View mView, String contentData, int startIndex, int endIndex,int typeFaceStyle){
        if(!contentData.isEmpty() && contentData.length() > endIndex) {
            final SpannableStringBuilder sb = new SpannableStringBuilder(contentData);

            final StyleSpan bss = new StyleSpan(typeFaceStyle); // Span to make text bold
            final StyleSpan iss = new StyleSpan(Typeface.NORMAL); //Span to make text italic
            sb.setSpan(iss, 0, startIndex, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
            sb.setSpan(bss, startIndex, endIndex, Spannable.SPAN_INCLUSIVE_INCLUSIVE); // make first 4 characters Bold
            sb.setSpan(iss,endIndex,contentData.length()-1,Spanned.SPAN_INCLUSIVE_INCLUSIVE);

            if(mView instanceof TextView)
                ((TextView) mView).setText(sb);
            else if(mView instanceof EditText)
                ((EditText) mView).setText(sb);
        }
    }