TextView text = (TextView)findViewById(R.layout.textName);
text.setTypeface(null,Typeface.BOLD);

1)你可以用字体设置。 2)你可以直接在strings.xml中使用(在你的values文件夹中) 3)你可以String myNewString = " This is my bold text This is my italics String This is my underscore String .

试着在TextView上设置粗体或斜体

textView.setTypeface(textView.getTypeface(), Typeface.BOLD);
textView.setTypeface(textView.getTypeface(), Typeface.ITALIC);
textView.setTypeface(textView.getTypeface(), Typeface.BOLD_ITALIC);

textView.setTypeface(null, Typeface.BOLD_ITALIC);
textView.setTypeface(null, Typeface.BOLD);
textView.setTypeface(null, Typeface.ITALIC);
textView.setTypeface(null, Typeface.NORMAL);

保持以前的字体

textView.setTypeface(textView.getTypeface(), Typeface.BOLD_ITALIC)

正如这里所解释的，如果你需要在你的样式文本资源中使用参数，你必须转义开括号

<resources>
<string name="welcome_messages">Hello, %1$s! You have &lt;b>%2$d new messages&lt;/b>.</string>
</resources>

然后调用formatHtml(string)

Resources res = getResources();
String text = String.format(res.getString(R.string.welcome_messages), username, mailCount);
CharSequence styledText = Html.fromHtml(text);

这是我在配置了OnePlus Slate™字体的OnePlus 5T上唯一有效的功能:

textView.setTypeface(Typeface.create(textView.getTypeface(), useBold ? Typeface.BOLD : Typeface.NORMAL));

其他方法将使它在BOLD或NORMAL时回落到Roboto。