Android字符高亮显示

1. String str="adsjoiasdjpaisdjpaidj";    
2. /** Called when the activity is first created. */   
3. @Override   
4. public void onCreate(Bundle savedInstanceState) {    
5.   super.onCreate(savedInstanceState);    
6.   setContentView(R.layout.main);    
7.   TextView textview=(TextView)findViewById(R.id.textView); 
   
8.   SpannableStringBuilder style=new SpannableStringBuilder(s
tr);    
9.   style.setSpan(new ForegroundColorSpan(Color.RED),3,8,Spann
able.SPAN_EXCLUSIVE_EXCLUSIVE);    
10.  textview.setText(style);    
11.}