blocks|key|1198122|text|由于安全原因，您不能这样做。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1198123|想象一下：|1198124|<form+name="foo"+method="post"+enctype="multipart/form-data">
++++<input+type="file"+value="c:/passwords.txt">
</form>
<script>document.foo.submit();</script>|code-block|syntax|javascript|1198125|你不希望你访问的网站能够做到这一点，不是吗？|1198126|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|O|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<p>You cannot, due to security reasons.</p>
<p>Imagine:</p>
<pre class="lang-html prettyprint-override"><code>&lt;form name=&quot;foo&quot; method=&quot;post&quot; enctype=&quot;multipart/form-data&quot;&gt;
    &lt;input type=&quot;file&quot; value=&quot;c:/passwords.txt&quot;&gt;
&lt;/form&gt;
&lt;script&gt;document.foo.submit();&lt;/script&gt;
</code></pre>
<p>You don't want the websites you visit to be able to do this, do you? =)</p>


blocks|key|1413527|text|你不能这么做。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1413528|设置文件输入的值的唯一方法是由用户选择一个文件。|1413529|这样做是出于安全原因。否则，您将能够创建自动从客户端计算机上载特定文件的JavaScript。|1413530|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|I|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|G|$]]

<p>You can't.</p>

<p>The only way to set the value of a file input is by the user to select a file.</p>

<p>This is done for security reasons. Otherwise you would be able to create a JavaScript that automatically uploads a specific file from the client's computer.</p>


blocks|key|1413468|text|你不能这么做。而且这是安全措施。想象一下，如果有人编写JS，将文件输入值设置为某个敏感数据文件？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1413469|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

<p>You can't. And it's a security measure. Imagine if someone writes JS that sets file input value to some sensitive data file?</p>


blocks|key|1413675|text|我已经写了加载URL到输入文件的完整示例，并预览|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1413676|📷|atomic|offset|length|1413677|您可以在此处查看1+https://vulieumang.github.io/vuhocjs/file2input-input2file/|1413678|简而言之，您可以使用此函数|1413679|function+loadURLToInputFiled(url){
++getImgURL(url,+(imgBlob)=>{
++++//+Load+img+blob+to+input
++++//+WIP:+UTF8+character+error
++++let+fileName+=+'hasFilename.jpg'
++++let+file+=+new+File([imgBlob],+fileName,{type:"image/jpeg",+lastModified:new+Date().getTime()},+'utf-8');
++++let+container+=+new+DataTransfer();+
++++container.items.add(file);
++++document.querySelector('#file_input').files+=+container.files;
++++
++})
}
//+xmlHTTP+return+blob+respond
function+getImgURL(url,+callback){
++var+xhr+=+new+XMLHttpRequest();
++xhr.onload+=+function()+{
++++++callback(xhr.response);
++};
++xhr.open('GET',+url);
++xhr.responseType+=+'blob';
++xhr.send();
}|code-block|syntax|javascript|1413680|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/fa337e770470e139251fbde89a096a9e.png|imageAlt|1|LINK|MUTABLE|url|2|https://vulieumang.github.io/vuhocjs/file2input-input2file/^0|0|0|1|0|0|8|1|1|A|1N|2|0|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|15|8|@]|9|@$E|16|F|17|1|18]]|A|$]]|$1|G|3|H|5|6|7|19|8|@]|9|@$E|1A|F|1B|1|1C]|$E|1D|F|1E|1|1F]]|A|$]]|$1|I|3|J|5|6|7|1G|8|@]|9|@]|A|$]]|$1|K|3|L|5|M|7|1H|8|@]|9|@]|A|$N|O]]|$1|P|3|-4|5|6|7|1I|8|@]|9|@]|A|$]]]|Q|$R|$5|S|T|U|A|$V|W|X|-4]]|Y|$5|Z|T|10|A|$11|W]]|12|$5|Z|T|10|A|$11|13]]]]

<p>I have write full example for load URL to input file, and preview
<a href="https://i.stack.imgur.com/GcgY7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GcgY7.png" alt="enter image description here" /></a>
you can check here
<a href="https://i.stack.imgur.com/GcgY7.png" rel="nofollow noreferrer">1</a>
<a href="https://vulieumang.github.io/vuhocjs/file2input-input2file/" rel="nofollow noreferrer">https://vulieumang.github.io/vuhocjs/file2input-input2file/</a></p>
<p>in short you can use this function</p>
<pre><code>function loadURLToInputFiled(url){
  getImgURL(url, (imgBlob)=&gt;{
    // Load img blob to input
    // WIP: UTF8 character error
    let fileName = 'hasFilename.jpg'
    let file = new File([imgBlob], fileName,{type:&quot;image/jpeg&quot;, lastModified:new Date().getTime()}, 'utf-8');
    let container = new DataTransfer(); 
    container.items.add(file);
    document.querySelector('#file_input').files = container.files;
    
  })
}
// xmlHTTP return blob respond
function getImgURL(url, callback){
  var xhr = new XMLHttpRequest();
  xhr.onload = function() {
      callback(xhr.response);
  };
  xhr.open('GET', url);
  xhr.responseType = 'blob';
  xhr.send();
}
</code></pre>


blocks|key|1413589|text|在html中定义：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1413590|<input+type="hidden"+name="image"+id="image"/>|code-block|syntax|javascript|1413591|在JS中：|1413592|ajax.jsonRpc("/consulta/dni",+'call',+{'document_number':+document_number})
++++.then(function+(data)+{
++++++++if+(data.error){
++++++++++++...;
++++++++}
++++++++else+{
++++++++++++$('#image').val(data.image);
++++++++}
++++})|1413593|之后：|1413594|<input+type="hidden"+name="image"+id="image"+value="/9j/4AAQSkZJRgABAgAAAQABAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8U..."/>
<button+type="submit">Submit</button>|1413595|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

<p>Define in html:</p>

<pre><code>&lt;input type="hidden" name="image" id="image"/&gt;
</code></pre>

<p>In JS:</p>

<pre><code>ajax.jsonRpc("/consulta/dni", 'call', {'document_number': document_number})
    .then(function (data) {
        if (data.error){
            ...;
        }
        else {
            $('#image').val(data.image);
        }
    })
</code></pre>

<p>After:</p>

<pre><code>&lt;input type="hidden" name="image" id="image" value="/9j/4AAQSkZJRgABAgAAAQABAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8U..."/&gt;
&lt;button type="submit"&gt;Submit&lt;/button&gt;
</code></pre>


blocks|key|1413558|text|实际上我们可以做到。我们可以使用FormToMultipartPostData在c#中使用webbrowser控件来设置文件值默认值，Library.We必须下载这个库并将其包含在我们的项目中。Webbrowser使用户能够在表单中导航网页。加载网页后，将执行webBrowser1_DocumentCompleted中的脚本。所以,|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1413559|private+void+webBrowser1_DocumentCompleted(object+sender,+WebBrowserDocumentCompletedEventArgs+e)
++++{
+++++++FormToMultipartPostData+postData+=+
++++++++++++new+FormToMultipartPostData(webBrowser1,+form);
++++++++postData.SetFile("fileField",+@"C:\windows\win.ini");
++++++++postData.Submit();
++++}|code-block|syntax|javascript|1413560|请参阅以下链接进行下载并完成参考。|1413561|https://www.codeproject.com/Articles/28917/Setting-a-file-to-upload-inside-the-WebBrowser-com|offset|length|1413562|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|0|2L|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|U|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|V|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|W|8|@]|9|@$K|X|L|Y|1|Z]]|A|$]]|$1|M|3|-4|5|6|7|10|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|J]]]]

<p>Actually we can do it.
we can set the file value default by using webbrowser control in c# using FormToMultipartPostData Library.We have to download and include this Library in our project. Webbrowser enables the user to navigate Web pages inside form.
Once the web page loaded , the script inside the webBrowser1_DocumentCompleted will be executed.
So,</p>

<pre><code>private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
    {
       FormToMultipartPostData postData = 
            new FormToMultipartPostData(webBrowser1, form);
        postData.SetFile("fileField", @"C:\windows\win.ini");
        postData.Submit();
    }
</code></pre>

<p>Refer the below link for downloading and complete reference.</p>

<p><a href="https://www.codeproject.com/Articles/28917/Setting-a-file-to-upload-inside-the-WebBrowser-com" rel="nofollow noreferrer">https://www.codeproject.com/Articles/28917/Setting-a-file-to-upload-inside-the-WebBrowser-com</a></p>


<p>How can I set the value of this?</p>

<pre><code>&lt;input type="file" /&gt;
</code></pre>


How to set a value to a file input in HTML?

我如何设置它的值？<input type="file" />

问如何为HTML中的文件输入设置值？
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问如何为HTML中的文件输入设置值？
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