如何更改文件中相似单词的颜色和字体

Question

我想更改文件中某些相同单词的颜色和字体

     private void readCode(String filename) throws Exception{
    File filesDir= 
    (Environment.getExternalStoragePublicDirectory
    (Environment.DIRECTORY_DOWNLOADS));
    File myFile=new File(filesDir,filename);

    BufferedReader br = new BufferedReader(new FileReader(myFile));

    String st;
    StringBuilder code= new StringBuilder("hello");

    while ((st = br.readLine()) != null)

    {

        SpannableString stt= new SpannableString(st);
        if(st.contains("import")){

            int index=st.indexOf("import");
            stt.setSpan(new ForegroundColorSpan(Color.RED), index,index+6, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

           }
        code.append(stt);
            code.append(System.getProperty("line.separator"));}
            myCOde.setText(code);




}

此代码不会更改文本的颜色，而只是将纯文本设置为文本视图