动态更换tab indicator

初始化

tabHost = getTabHost();  
TabSpec tabSpec = tabHost.newTabSpec("abc"); 
tabSpec.setIndicator("helloabc"); 
tabSpec.setContent(new MyViewFactory()); 
tabHost.addTab(tabSpec);

TextView title = (TextView) tabHost.getTabWidget()
.getChildAt(tabId).findViewById(android.R.id.title) ;
title.setText("xyz");