EditText mEdit = new EditText(context);

InputType.TYPE_NUMBER_FLAG_DECIMAL、小数点型

InputType.TYPE_CLASS_NUMBER 整数型

设置Input的类型两种都要

mEdit.setInputType(InputType.TYPE_NUMBER_FLAG_DECIMAL|InputType.TYPE_CLASS_NUMBER);

设置字符过滤

mEdit.setFilters(new InputFilter[]{new InputFilter() {
    @Override
    public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
        if(source.equals(".") && dest.toString().length() == 0){
            return "0.";
        }

        if(dest.toString().contains(".")){
            int index = dest.toString().indexOf(".");
            int mlength = dest.toString().substring(index).length();
            if(mlength == 3){
                return "";
            }
        }
        return null;
    }
}});

Android EditText 输入金额（小数点后两位）