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)

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);

试试这个:

TextView textview = (TextView)findViewById(R.id.textview_idname);
textview.setTypeface(null,Typeface.BOLD);

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);

编程:

你可以通过编程方式使用setTypeface():

textView.setTypeface(null, Typeface.NORMAL);      // for Normal Text
textView.setTypeface(null, Typeface.BOLD);        // for Bold only
textView.setTypeface(null, Typeface.ITALIC);      // for Italic
textView.setTypeface(null, Typeface.BOLD_ITALIC); // for Bold and Italic

XML:

你可以在<TextView />中的XML文件中直接设置如下:

android:textStyle="normal"
android:textStyle="normal|bold"
android:textStyle="normal|italic"
android:textStyle="bold"
android:textStyle="bold|italic"