简单实现php上传文件功能

<form action="upload_file.php" method="post" enctype="multipart/form-data">  <label for="file">文件名：</label>  <input type="file" name="file" id="file"><br>  <input type="submit" name="submit" value="提交"></form>

<?php// 允许上传的图片后缀$allowedExts = array("gif", "jpeg", "jpg", "png");$temp = explode(".", $_FILES["file"]["name"]);echo $_FILES["file"]["size"];$extension = end($temp);   // 获取文件后缀名if ((($_FILES["file"]["type"] == "image/gif")|| ($_FILES["file"]["type"] == "image/jpeg")|| ($_FILES["file"]["type"] == "image/jpg")|| ($_FILES["file"]["type"] == "image/pjpeg")|| ($_FILES["file"]["type"] == "image/x-png")|| ($_FILES["file"]["type"] == "image/png"))&& ($_FILES["file"]["size"] < 204800)  // 小于 200 kb&& in_array($extension, $allowedExts)){  if ($_FILES["file"]["error"] > 0)  {    echo "err";  }  else  {    echo "上传文件名: " . $_FILES["file"]["name"] . "<br>";    echo "文件类型: " . $_FILES["file"]["type"] . "<br>";    echo "文件大小: " . ($_FILES["file"]["size"] / 1024) . " kB<br>";    echo "文件临时存储的位置: " . $_FILES["file"]["tmp_name"] . "<br>";        // 判断当期目录下的 upload 目录是否存在该文件    // 如果没有 upload 目录，你需要创建它，upload 目录权限为 777    if (file_exists("../../../Content/UploadFiles/00/00/00/" . $_FILES["file"]["name"]))    {      echo "err";    }    else    {      // 如果 upload 目录不存在该文件则将文件上传到 upload 目录下      move_uploaded_file($_FILES["file"]["tmp_name"], "../../../Content/UploadFiles/00/00/00/" . $_FILES["file"]["name"]);    }  }}else{  echo "err";}?>