如何在没有提交按钮的情况下上传文件？

Question

我试图让我的上传按钮将文件上传到临时目录，而无需单击提交按钮，但我收到一条错误消息：无法读取未定义的属性（读取“路径”）。

html.js     

<style>     

input[type="file"] {
position: absolute;
z-index: -1;
top: 15px;
left: 20px;
font-size: 1px;
color: #b8b8b8;
}
.button-wrap {
    position: relative;
}

</style>
<div class="button-wrap">
     <form id="fileUploadForm" action="/fileUpload" 
          enctype="multipart/form-data" method="POST">
          <label class="button" for="upload">Upload File</label>
          <input id="upload" name="upload" type="file" 
          onchange="fileUploadForm.submit()">
     </form>
</div>

node.js 

app.post('/fileUpload', upload.single('filetoupload'), (req, res, err)=>{

var filepath = req.file.path
filename = './public/temp/' + req.file.filename
var jFile =  filename + '.json'




console.log(req, fileStorage, "filename: ",filename, "filepath: ",filepath, "jFile,",  
jFile);

res.status(204).end();
});

Answer 1

Your HTML should be:

<div class="button-wrap">
         <form id="fileUploadForm" action="/fileUpload" enctype="multipart/form-data" method="POST">
            <label class="button" for="upload">Upload File</label>
            <input id="upload" name="upload" type="file" onchange="fileUploadForm.submit()">
        </form>
 </div>

Answer 2

检查您的请求 object上的内容。 错误：“无法读取未定义的属性（读取'路径'）。” 表示属性“req.file”未定义。 我相信您应该使用输入的名称而不是输入的类型来访问它（在本例中为“req.filetoupload.path”）