How to set TextView textStyle such as bold, italic

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

To keep the previous typeface

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

You have two options:

Option 1 (only works for bold, italic and underline):

String s = "<b>Bolded text</b>, <i>italic text</i>, even <u>underlined</u>!"
TextView tv = (TextView)findViewById(R.id.THE_TEXTVIEW_ID);
tv.setText(Html.fromHtml(s));

Option 2:

Use a Spannable; it is more complicated, but you can dynamically modify the text attributes (not only bold/italic, also colors).

Programmatically:

You can do programmatically using 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:

You can set Directly in XML file in <TextView /> like:

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

Try this to set on TextView for bold or italic

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