public class TextHtmlActivity extends Activity {
    private TextView text;
    private Activity mActivty;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.text_html_layout);
        mActivty = this;
        text  = (TextView) findViewById(R.id.text);
        text.setText(Html.fromHtml("<b>text3:</b>  " +
                "Text with a " + "<a href=\"http://www.baidu.com\">link</a> " +
                "點選這個連線---"+
                "<a href=\"http://www.dewen.io/q/1744\">連線</a> "+
                "created in the Java source code using HTML."));
        text.setMovementMethod(LinkMovementMethod.getInstance());
        CharSequence str = text.getText();
        if(str instanceof Spannable){
            int end = str.length();
            Spannable sp = (Spannable)text.getText();  //構建Spannable物件、繼承Spanned、Spanned物件繼承CharSequener
            URLSpan[] urls=sp.getSpans(0, end, URLSpan.class);  //找出text中的a標籤
            //SpannableStringBuilder、SpannableString物件跟String物件差不多、只是比String物件多setSpan，
            //可以給字串設定樣式、大小、背景色...而 SpannableStringBuilder跟SpannableString的關係就跟String跟StringBuffer關係一樣
            SpannableStringBuilder style=new SpannableStringBuilder(str);
            style.clearSpans();//should clear old spans
            for(URLSpan url : urls){
                MyClickSpan myURLSpan = new MyClickSpan();
                //設定樣式其中引數what是具體樣式的實現物件，start則是該樣式開始的位置，end對應的是樣式結束的位置，
                // 引數 flags，定義在Spannable中的常量
                style.setSpan(myURLSpan,sp.getSpanStart(url),sp.getSpanEnd(url),Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            }
            text.setText(style);
        }

    }
    private class MyClickSpan extends ClickableSpan{
        @Override
        public void updateDrawState(TextPaint ds) {
            ds.setUnderlineText(false);
            super.updateDrawState(ds);
        }
        @Override
        public void onClick(View widget) {
            Toast.makeText(mActivty,"click link",Toast.LENGTH_SHORT).show();
        }
    }
}