在經過上面的簡單的小部落格講解後，今天就把前端和後端的程式碼粗略的弄一下。大致的程式碼如下： 

{#  上傳檔案的時候必須要在form標籤中新增屬性 enctype="multipart/form-data"  #}
<form method="POST"  enctype="multipart/form-data" id="upload" >
    <div class="col-lg-12">
    <div class="col-lg-8">
        <input type="file" name="img" id="img" class="btn btn-default"/>
        <input type="text" name="companyF" id="companyF" value="{{ company_name }}" style="display: none;"/>
        <input type="text" name="coverFile" id="coverFile" value="False" style="display: none;"/>
    </div>
    <div class="col-lg-4" style="text-align: center;">
        <input type="button" class="btn btn-default" value="上傳附件" onclick="transferBtn(this)" />
    </div>
    <div class="col-lg-4" style="text-align: center;">
        <input type="button" class="btn btn-default" value="下載檔案" onclick="downloadFiles()" />
    </div>
    </div>
</form>
 

  //上傳檔案按鈕
    function transferBtn(cur){
      var form = document.getElementById('upload'),
      formData = new FormData(form);
      $.ajax({
       url:"{% url 'upload' %} ",
       type:"post",
       data:formData,
       processData:false,
       contentType:false,
       success:function(data){
            if(data == 'ok'){
                layer.msg("上傳成功！");
            }
            if(data == 'exists'){
                //詢問框
            layer.confirm('已有該檔案，是否覆蓋？', {
                btn: ['確定', '取消'],
            }, //按鈕
            function () {
                coverFile();
            },
            function () {
                layer.msg('取消操作成功');
            });
            }
      }

    })
    }
    //覆蓋檔案的操作
    function coverFile() {
        var form = document.getElementById('upload');
        $("#coverFile").val('True');
        formData = new FormData(form);
        $.ajax({
           url:"{% url 'upload' %} ",
           type:"post",
           data:formData,
           processData:false,
           contentType:false,
           success:function(data){
               layer.msg('覆蓋檔案成功');
           }
        })
    }
 

def upload(request):
    if request.method == "POST":
        company = request.POST.get("companyF")
        file = request.FILES.get('img')      # 所有提交的檔案
        coverFile = request.POST.get("coverFile")

        file_name = file.name
        path = tools.DOC_BASE_DIR + request.user.username + '/' + company + '/'
        all_path = path + file_name
        if os.path.exists(path) is False:
            os.makedirs(path)

        if os.path.exists(all_path) and coverFile == 'False':
            return HttpResponse('exists')
        with open(all_path, 'wb') as f:
            for chunk in file.chunks():
                f.write(chunk)
        return HttpResponse("ok")

    # return render(request, 'report_template.html')
 

def fileExistsOrNot(request):
    company_name = request.POST.get("company_name")
    file_name = request.POST.get("file_name")
    path = tools.DOC_BASE_DIR + request.user.username + '/' + company_name + '/' + file_name

    if os.path.exists(path):
        return HttpResponse("檔名已存在")
    else:
        return HttpResponse("OK")