如何将名称值数据添加到Android HTTP文件上载POST请求

I have an android photo upload script that uploads fine if I use $_GET to read some data, I want to use all $_POST. The problem is I need to append data do the posted request to include basic name value pairs along with the file upload. I can get this to work if I have the server use $_GET and just add the extra data in the url string, but I want to use post. Is there a way to encode other post data in the file upload that the server can read using $_POST. Heres the function, notice the URL string where, I'm trying to get the variables api_key,session_key, and method to be sent in the POST request.I have an android photo upload script that uplo