How to encode DirectMethod 's post request

hi

i have textfield and button in form panel.
When button is clicked, it call directmethod like 'app.direct.foo();'

It doesn't work if the text field value is '<test>

when i call direct method, it request post message with textfield's raw value

like.
-------------------------------7e414f36015e
Content-Disposition: form-data; name ="ct100_ContentPlaceHolderContext_txtTitle"
<test>
-------------------------------7e414f36015e
...


i think it need to encdoe.
how can i encode textfield value?