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);
        }
    }

根据@mladj0ni的回答，我得到了下面的代码。问题是如果你使用String。格式，它剥离了HTML标记，所以你必须转义strings.xml中的括号符号:

strings.xml:

<string name="welcome_messages">Hello， %1$s!你有&lt;b>%2$d新消息&lt;/b>.</string> .</string> .

code.java:

String unspanned = String.format(Locale.US, "%s%s", getResources().getString(R.string. welcome_messages), 99);

Spanned spanned;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
    spanned = Html.fromHtml(unspanned, Html.FROM_HTML_MODE_LEGACY);
} else {
    spanned = Html.fromHtml(unspanned);
}

textView.setText(spanned);

它比SpannableStringBuilder简单。至于性能，如果只显示一个字符串，那么用户不会注意到解析它所花费的额外毫秒。

请在这里查看文档。

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);
        }
    }

如果粗体文本的位置是固定的(例如:如果是在textView的开始)，然后使用两个不同的textView具有相同的背景。然后你可以使其他textView的textStyle为粗体。

与单个textView相比，这将需要两倍的内存，但速度会提高。

wtsang02答案是最好的方法，因为，Html.fromHtml("")现在已弃用。这里我要稍微加强一下，以方便那些在动态地将第一个单词加粗方面有问题的人，不管句子的大小。

首先让我们创建一个方法来获取第一个单词:

 private String getFirstWord(String input){

    for(int i = 0; i < input.length(); i++){

        if(input.charAt(i) == ' '){

            return input.substring(0, i);
        }
    }

    return input;
}

现在假设你有一个像这样的长字符串:

String sentence = "friendsAwesomeName@gmail.com want's to be your friend!"

你希望你的句子是yourAwesomeName@gmail.com想成为你的朋友! 你所要做的就是-获取firstWord并获取它的长度以使firstWord加粗，就像这样:

String myFirstWord = getFirstWord(sentence);
int start = 0; // bold will start at index 0
int end = myFirstWord.length(); // and will finish at whatever the length of your first word

现在按照wtsang02的步骤来做，就像这样:

SpannableStringBuilder fancySentence = new SpannableStringBuilder(sentence);
fancySentence.setSpan(new android.text.style.StyleSpan(Typeface.BOLD), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(fancySentence);

就是这样!现在你应该可以在长句或短句中加粗任意大小的单词了。

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>