将自定义字体设置为动态添加的文本视图android

我在运行时将TextView添加到LinearLayout。
我想在运行时从我的assets/fonts/文件夹中设置一种字体。
我已完成以下操作，但无法正常工作：

private ArrayList<TextView> getExperTextViews() {
    ArrayList<TextView> textViewArrayList = new ArrayList<>();
    TextView tv_title = new TextView(DesignerDetailActivity.this);
    LinearLayout.LayoutParams parms = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
            LinearLayout.LayoutParams.WRAP_CONTENT);
    parms.setMargins(0,0,0,5);
    tv_title.setLayoutParams(parms);
    Typeface font=Typeface.createFromAsset(getAssets(), "fonts/OpenSans-Bold.ttf");
    tv_title.setTypeface(font);
    tv_title.setText("EXPERTISE");

    tv_title.setTextSize(16);

    textViewArrayList.add(tv_title);
    ArrayList<DesignerExpertise> designerExpertiseArrayList = designer.getExpertiseArrayList();


    String expertiseString = "<font color='#a8a8a8'>{property}</font> &nbsp;";
    for (int i = 0; i < designerExpertiseArrayList.size(); i++) {
        TextView tv = new TextView(DesignerDetailActivity.this);
        tv.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
                LinearLayout.LayoutParams.WRAP_CONTENT));
        DesignerExpertise designerExpertise = designerExpertiseArrayList.get(i);
        ArrayList<DesignerExpertiseValue> designerExpertiseValueArrayList = designerExpertise.getDesignerExpertiseValues();

        String newExpertiseString = expertiseString.replace("{property}", designerExpertise.getProperty().toUpperCase());
        newExpertiseString = newExpertiseString + designerExpertiseValueArrayList.get(0).getName();
        for (int j = 1; j < designerExpertiseValueArrayList.size(); j++) {
            newExpertiseString = newExpertiseString + " ," + designerExpertiseValueArrayList.get(1).getName();
        }
        Typeface _font=Typeface.createFromAsset(getAssets(), "fonts/OpenSans-Regular.ttf");
        tv_title.setTypeface(_font);

        tv.setText(Html.fromHtml(newExpertiseString), TextView.BufferType.SPANNABLE);
        tv.setTextSize(16);
        tv.setPadding(0,5,0,5);
        textViewArrayList.add(tv);
    }
    return textViewArrayList;
}

请帮我。