django的ImageField的上傳總是抱怨沒有文件被選擇

我試圖建立個人資料圖像上傳字段：django的ImageField的上傳總是抱怨沒有文件被選擇

class SignUpForm(forms.Form): 
    username = forms.CharField(max_length=30, \ 
     error_messages = {'required': 'Need a username'}) 
    email = forms.EmailField(max_length=30, \ 
     error_messages = {'required': 'Need an email', 'invalid': 'Email is invalid'}) 
    profile_image = forms.ImageField(error_messages = {'required': 'Please select a profile image'})

和負載數據在views.py：

if request.method != 'POST': 
    return HttpResponseServerError("Only POST requests allowed.") 
    form = SignUpForm(request.POST, request.FILES) 
    logger.info(request.FILES) # this always prints empty '{}'

形式是：

form(enctype="multipart/form-data", method='post') 
     label(for='username') Username 
     input#name(name='username', type='text') 
     label(for='email') Email 
     input#email(name='email', type='email') 
     label(for='profile_image') Profile Image 
     input#profile_image(name='profile_image', type='file')

我提交的數據的方法是在JS：

$('form').submit(function(e){ 
    e.preventDefault(); 
    $("#signup-errors").hide(); 
    var form = $(e.target); 
    var post = $.post('/user/create/', form.serialize(), redirectIfSuccess); 
    post.fail(function(xhr, ajaxOptions, thrownError) { 
    $("#signup-errors").html(xhr.getResponseHeader("errors")).show(); 
    }); 
});

有人可以提示我什麼可能是錯的？我已經搜查和採取的步驟，但這些文件從來不張貼通... :(

感謝！

來源

2013-06-12 Frost