创建登录屏幕以链接到iOS应用程序中的表单

I wish to create a login screen which only shows in the app once and basically it would just have a "Username" and Password" field. When the "Login" button is pressed, I would like the data from the "Username" and "Password" fields to be input into a form and then submit the data to an action (such as "/index.phtml?d=187209&destination_page=187224").I wish to create a login screen which only show