Detailed example of ajax implementation of uploading files without refreshing-PHP Tutorial-php.cn

Detailed example of ajax implementation of uploading files without refreshing

小云云

Release： 2023-03-18 06:02:01

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This article mainly introduces the function of ajax to upload files without refreshing in detail. It has certain reference value. Interested friends can refer to it. I hope it can help everyone.

The detailed code is as follows

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>ajax无刷新上传文件</title>
<script>
window.onload = function(){
  var oBtn = document.getElementById(&#39;btn&#39;);
  var oMyFile = document.getElementById(&#39;myFile&#39;);

  oBtn.onclick = function() {
    //alert(oMyFile.value); //获取到的是file控件的value值,这个内容是显示给你看的文字,不是我们选择的文件

    //oMyFile.files file控件中选择的文件列表对象
    //alert(oMyFile.files);

    //我们是要通过ajax把oMyFile.files[0]数据发送给后端

    /*
    for (var attr in oMyFile.files[0]) {
      console.log( attr + &#39; : &#39; + oMyFile.files[0][attr] );
    }
    */

    //利用ajax发送必须要有一个ajax对象
    var xhr = new XMLHttpRequest();

    //监听上传事件
    xhr.onload = function(){
      //alert(1);
      //alert(this.responseText);//后端返回的数据
      var d = JSON.parse(this.responseText);

      alert(d.msg + &#39; : &#39; + d.url); //显示上传成功 并且显示文件路径
    }

    xhr.open(&#39;post&#39;,&#39;post_file.php&#39;,true); //open打开的方式不能使用get,上传文件的地址,使用异步上传
    //在使用post发送的时候必须要带一些请求头信息
    xhr.setRequestHeader(&#39;X-Request-With&#39;, &#39;XMLHttpRequest&#39;);
    //send要发送数据 
    //将要上传的数据转换成二进制数据
    //那么必须知道后端接收当前文件的名称是什么 然后后面带上当前文件的数据

    var oFormData = new FormData(); //通过FormData来构建提交数据
    oFormData.append(&#39;file&#39;,oMyFile.files[0]);

    xhr.send(oFormData);
  }
}
</script>
</head>
<body>
  <input type="file" id="myFile" /><input type="button" id="btn" value="上传" />
</body>
</html>

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Backend php code post_file.php

<?php
header(&#39;Content-type:text/html; charset="utf-8"&#39;);
$upload_dir = &#39;uploads/&#39;;

if(strtolower($_SERVER[&#39;REQUEST_METHOD&#39;]) != &#39;post&#39;){
  exit_status(array(&#39;code&#39;=>1,&#39;msg&#39;=>&#39;错误提交方式&#39;));
}

if(array_key_exists(&#39;file&#39;,$_FILES) && $_FILES[&#39;file&#39;][&#39;error&#39;] == 0 ){

  $pic = $_FILES[&#39;file&#39;];

  if(move_uploaded_file($pic[&#39;tmp_name&#39;], $upload_dir.$pic[&#39;name&#39;])){
    exit_status(array(&#39;code&#39;=>0,&#39;msg&#39;=>&#39;上传成功&#39;,&#39;url&#39;=>$upload_dir.$pic[&#39;name&#39;]));
  }
}
echo $_FILES[&#39;file&#39;][&#39;error&#39;];
exit_status(array(&#39;code&#39;=>1,&#39;msg&#39;=>&#39;出现了一些错误&#39;));

function exit_status($str){
  echo json_encode($str);
  exit;
}
?>

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