字体样式。

构造函数：

• TextAppearanceSpan(Context context, int appearance)：参数context，传入的上下文，参数appearance，引用的样式表，如R.style.my_style。
• TextAppearanceSpan(Context context, int appearance, int colorList)： 参数context，使用的上下文，参数appearance，引用的样式表，如R.style.my_style， 参数colorList，使用方式未知，如果设置为小于0，则参数将不产生效果。
• TextAppearanceSpan(String family, int style, int size, ColorStateList color, ColorStateList linkColor)： 参数family，字体，仅支持系统自带的三种字体，MONOSPACE、SERIF和SANS， 参数style，TypeFace中定义的字体样式，BOLD、ITALIC等， 参数size，字体大小，参数color，字体颜色，参数linkColor，使用方式未知。
• TextAppearanceSpan(Parcel src)：参数src，含有样式信息的包装类

示例1：

TextAppearanceSpan textAppearanceSpan = new TextAppearanceSpan(context, R.style.xx);

String text = "打开百度";
SpannableString spannableString = new SpannableString(text);
spannableString.setSpan(textAppearanceSpan, 2, text.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);

TextView textView = (TextView) findViewById(R.id.text_view);
textView.setText(spannableString);

示例2：

Parcel parcel = Parcel.obtain();
parcel.writeString("SERIF");
parcel.writeInt(Typeface.BOLD_ITALIC);
parcel.writeInt(18);
try {
    ColorStateList colorList = ColorStateList.createFromXml(context.getResources(), context.getResources().getXml(R.drawable.color_list));
    parcel.writeInt(1);
    colorList.writeToParcel(parcel, Parcelable.PARCELABLE_WRITE_RETURN_VALUE);
    parcel.writeInt(1);
    colorList.writeToParcel(parcel, Parcelable.PARCELABLE_WRITE_RETURN_VALUE);
} catch (Exception e) {
    e.printStackTrace();
}
parcel.setDataPosition(0);

TextAppearanceSpan textAppearanceSpan = new TextAppearanceSpan(parcel);

String text = "打开百度";
SpannableString spannableString = new SpannableString(text);
spannableString.setSpan(textAppearanceSpan, 2, text.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);

TextView textView = (TextView) findViewById(R.id.text_view);
textView.setText(spannableString);

示例3：

重写updateDrawState(TextPaint textPaint)方法，修改字体的样式、文本颜色：

TextAppearanceSpan textAppearanceSpan = new TextAppearanceSpan(this, R.style.xx) {
    @Override
    public void updateDrawState(TextPaint textPaint) {
        super.updateDrawState(textPaint);
        textPaint.setColor(Color.argb(255, 54, 92, 124));
    }
};

String text = "打开百度";
SpannableString spannableString = new SpannableString(text);
spannableString.setSpan(typefaceSpan, 2, text.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);

TextView textView = (TextView) findViewById(R.id.text_view);
textView.setText(spannableString);