SpannableStringBuilder style=new SpannableStringBuilder(str);
//SpannableStringBuilder實現CharSequence接口
style.setSpan(new ForegroundColorSpan(Color.RED), 0, 2,Spannable.SPAN_EXCLUSIVE_EXCLUSIVE );
style.setSpan(new ForegroundColorSpan(Color.YELLOW), 2, 4,Spannable.SPAN_EXCLUSIVE_EXCLUSIVE );
style.setSpan(new ForegroundColorSpan(Color.GREEN), 4, 6,Spannable.SPAN_EXCLUSIVE_EXCLUSIVE );
tv.setText(style);//將其添加到tv中

tv.setText(Html.fromHtml("我是<font color=blue>danyijiangnan</font>"));