HTML5 FormData實現文件上傳實例

表單提交，文件上傳是一個經常使用又十分麻煩的功能，之前要上傳文件一般都是藉助插件或者flash來實現，噼裏啪啦的加載一大堆東西。自從有了HTML5的FormData後，老闆不再用擔憂個人上傳了。javascript

FormData能夠把它理解成一個虛擬的表單對象，它只有一個方法append，這個能夠在瀏覽器console一下就知道了。咱們能夠經過append向FormData裏面添加各類須要提交的數據。php

你能夠先建立一個空的 FormData 對象,而後使用 append() 方法向該對象裏添加字段，以下：var oMyForm = new FormData();html

 oMyForm.append("username", "Groucho"); oMyForm.append("accountnum", 123456); // 數字123456被當即轉換成字符串"123456" // fileInputElement中已經包含了用戶所選擇的文件 oMyForm.append("userfile", fileInputElement.files[0]);var oReq = new XMLHttpRequest(); oReq.open("POST", "http://foo.com/submitform.php"); oReq.send(oMyForm);

若是已經有一個Form表單，只須要把這個 form 元素做爲參數傳入 FormData 構造函數便可：java

var newFormData = new FormData(someFormElement);

var formElement = document.getElementById("myFormElement"); var oReq = new XMLHttpRequest(); oReq.open("POST", "submitform.php"); oReq.send(new FormData(formElement));

你還能夠在已有表單數據的基礎上，繼續添加新的鍵值對，以下：ajax

var formElement = document.getElementById("myFormElement"); formData = new FormData(formElement); formData.append("serialnumber", serialNumber++); oReq.send(formData);

<form enctype="multipart/form-data" method="post" name="fileinfo">
  <label>Your email address:</label>
  <input type="email" autocomplete="on" autofocus name="userid" placeholder="email" required size="32" maxlength="64" /><br />
  <label>Custom file label:</label>
  <input type="text" name="filelabel" size="12" maxlength="32" /><br />
  <label>File to stash:</label>
  <input type="file" name="file" required />
</form>
<div id="output"></div>
<a href="javascript:sendForm()">Stash the file!</a>

而後你就可使用下面的代碼來異步的上傳用戶所選擇的文件：json

function sendForm() { var oOutput = document.getElementById("output"); var oData = new FormData(document.forms.namedItem("fileinfo")); oData.append("CustomField", "This is some extra data"); var oReq = new XMLHttpRequest(); oReq.open("POST", "stash.php", true); oReq.onload = function(oEvent) { if (oReq.status == 200) { oOutput.innerHTML = "Uploaded!"; } else { oOutput.innerHTML = "Error " + oReq.status + " occurred uploading your file.<br \/>"; } }; oReq.send(oData); }

你還可使用 jQuery 來發送 FormData，但必需要正確的設置相關選項：瀏覽器

var fd = new FormData(document.getElementById("fileinfo")); fd.append("CustomField", "This is some extra data"); $.ajax({ url: "stash.php", type: "POST", data: fd, processData: false,  // 告訴jQuery不要去處理髮送的數據
  contentType: false   // 告訴jQuery不要去設置Content-Type請求頭
});

一個完整的例子：app

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>FormData</title>
</head>
<body>
    <form name="form1" id="form1">  
        <p>name:<input type="text" name="name" ></p>  
        <p>gender:<input type="radio" name="gender" value="1">male <input type="radio" name="gender" value="2">female</p>  
        <p>photo:<input type="file" name="photo" id="photo"></p>  
        <p><input type="button" name="b1" value="submit" onclick="fsubmit()"></p>  
    </form>  
    <div id="result"></div>
</script>
    <script type="text/javascript">
        function fsubmit() { var form=document.getElementById("form1"); var formData=new FormData(form); var oReq = new XMLHttpRequest(); oReq.onreadystatechange=function(){ if(oReq.readyState==4){ if(oReq.status==200){ var json=JSON.parse(oReq.responseText); var result = ''; // result += 'name=' + ret['name'] + '<br>';
                    // result += 'gender=' + ret['gender'] + '<br>';
 result += '<img src="' + json['photo'] + '" width="100">'; $('#result').html(result); } } } oReq.open("POST", "server.php"); oReq.send(formData); return false; } </script>
</body>
</html>

server.php文件：異步

<?php $name = isset($_POST['name'])? $_POST['name'] : ''; $gender = isset($_POST['gender'])? $_POST['gender'] : ''; $filename = time().substr($_FILES['photo']['name'], strrpos($_FILES['photo']['name'],'.')); $response = array(); if(move_uploaded_file($_FILES['photo']['tmp_name'], $filename)){ $response['isSuccess'] = true; $response['name'] = $name; $response['gender'] = $gender; $response['photo'] = $filename; }else{ $response['isSuccess'] = false; } echo json_encode($response); ?>