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"

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)

TextView text = (TextView)findViewById(R.id.THE_TEXTVIEW_ID);

现在设置textview属性..

text.setTypeface(null, Typeface.BOLD);  //-- for only bold the text
text.setTypeface(null, Typeface.BOLD_ITALIC);  //-- for  bold & italic the text
text.setTypeface(null, Typeface.ITALIC);  // -- for  italic the 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"

你可以这样做:

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

如果你想保留之前的字体，不想失去之前应用的字体，那么另一个选择:

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

试试这个:

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