ExtJS 4使用Ext.form.field.File而不是Ext.Form.Panel如何提交

I'm using Ext.Form.Panel successfully but I want to use Ext.form.field.File this time. I was able to submit and upload the data putting the field.file info a form.Panlen which I think is not the only option. For now I have:I'm using Ext.Form.Panel successfully but I wan