PHP 无法获取文件

Question

我一直在尝试创建一个注册表单，要求学生在最后上传文件。但是，通过 jQuery 获取表单值后，PHP 文档似乎无法获取我上传的表单。有任何想法吗？

表格：

<form id="joinUs"  enctype="multipart/form-data" method="post">
   <!--various form fields-->
    <input type="file" name="transcript" id="transcript">
    <div class="button" id="submit">Submit!</div>
</form>

jQuery：

$("#submit").click(function(){
    //firstName, lastName, grade, studentID, email, phone are all form values
   var data = "firstName="+firstName+"&lastName="+lastName+"&grade="+grade+"&studentID="+studentID+"&email="+email+"&phone="+phone;
         $.ajax({
                            type: "POST",
                            url: "join_submit.php",
                            data: data,
                            success: function() {                                        
                                   location.href="http://mvcsf.com/new/success.php";

                            }
                    });

join_submit.php

  $allowedExtensions = array("pdf");
$max_filesize = 20000;
$upload_path = "docs/transcripts";
$filename = $_FILES["transcript"]["name"];          
$filesize = $_FILES["transcript"]["size"];
$extension = $_FILES["transcript"]["type"];
 if ($_FILES["transcript"]["error"] > 0) {
        echo "Error: " . $_FILES["transcript"]["error"] . "<br />";
    }
else if((in_array($extension, $allowedExtensions)) && ($filesize < $max_filesize)) {
    move_uploaded_file($_FILES["transcript"]["tmp_name"], $upload_path . $filename);
}

我运行了这个，没有出错。我也尝试打印出文件名，除了没有打印出来。

Answer 1

这应该为你做：

$("#submit").click(function () {

        var transcript = $("#transcript").val();

        var data = "firstName=" + firstName + "&lastName=" + lastName + "&grade=" + grade + "&studentID=" + studentID + "&email=" + email + "&phone=" + phone;
        var formData = new FormData();

        formData.append("file", transcript);
        formData.append("data", data);

        $.ajax({
            type: "POST",
            url: "join_submit.php",
            enctype: 'multipart/form-data',//optional
            cache: false,
            contentType: false,
            processData: false,
            data: {
                file: file
                data: data
            },
            success: function () {
                location.href = "http://mvcsf.com/new/success.php";

            }
        });
});

干杯

Answer 2

首先，在您的代码中，您使用$.ajax({...}) 发布数据，发送的数据是

"firstName="+firstName+"&lastName="+lastName+"&grade="+grade+"&studentID="+studentID+"&email="+email+"&phone="+phone;

根本没有transcript。

其次，也是最重要的，你不能像这样使用$.ajax({...}) 发布文件，它不会那样工作。正如@Roy M J 所说，你应该看看FormData（仅适用于最近的浏览器），或者在网上查看一个上传jQuery插件（不要重新发明，一些好的插件已经存在:)）

看看here

Answer 3

您不能像发送 HTML 元素的值那样发送文件。文件上传有两种方法，我使用成功的一种是使用名为“AjaxUploader”的第三方功能的AJAX方法。您可以通过GitHubdownload it here。完成后，将 ajaxuploader.js 文件添加到您的“js”文件夹（或您放置所有脚本文件的任何位置）中，将该文件包含在您必须使用上传器的 HTML 页面中。现在，上传很简单，如下所示。
HTML：

<input type="file" name="transcriptUploader" id="transcriptUploader" value="Upload" />

jQuery（您需要将 jQuery 文件包含在您的页面中）：

            new AjaxUpload('transcriptUploader', { 
            action: "page_to_handle_upload.php", // You need to have either a separate PHP page to handle upload or a separate function. Link to either one of them here
            name: 'file',
            onSubmit: function(file, extension) {
                // This function will execute once a user has submitted the uploaded file. You can use it to display a loader or a message that the file is being uploaded.
            },
            onComplete: function(file, response) {
                // This function will execute once your file has been uploaded successfully.
                var data = $.parseJSON(response); // Parsing the returning response from JSON.
                if(data.error == 0)
                {
                    // If the file uploaded successfully.
                }
                else if(data.error == "size"){
                    // If the response object sent 'size' as the error. It means the file size exceeds the size specified in the code.
                }
                else if(data.error == "type"){
                    // If the response object sent 'type' as the error. It means the file type is not of that specified in the code (in your case, pdf).
                }
                else{
                    // In case the file didn't upload successfully or the code didn't return a usual error code. It is still an error so you need to deal with it appropriately.
                }

            }
        });

您的后端 PHP 代码将完成所有繁重工作（上传文件、检查扩展名、移动文件等）：

if(isset($_FILES)) // Checking if a file is posted.
{
    if ($_FILES['file']['error'] == 0) //Checking if file array contain 0 as an error. It means AJAX had no error posting the file.
    {
        $response = array(); // Initializing a new array.
        $allowedExts = array("pdf"); // Allowable file format.
        $filename = stripslashes($_FILES['file']['name']); // Storing file name.
        //$extension = strtolower(self::_getExtension($filename)); // Fetching file extension.
        // Code block to extract file extension and storing it in a variable called $extraction.
        $i = strrpos($str, ".");
        if (!$i)
        {
            $extension = "";
        }
        $l = strlen($str) - $i;
        $extension = strlower(substr($str, $i + 1, $l));
        $size = $_FILES['file']['size']; // Storing file size (in bytes).
        $fileNameAfterUpload =  md5((time() + microtime())) . '.' . $extension; // Concatinating file name and extension.
        $baseSystemPath = "/var/www/<your_folder_name>/uploaded_transcripts/" // Path on which the file will be uploaded. Need to be relative web path.
        $maxSize = 10*10*1024; // Storing file size. Be advised the file size is in bytes, so this calculation means max file size will be 10 MB.
        $webPath =  "uploaded_transcripts/". $filename; // Creating web path by concatinating base web path (the folder in which you'd be uploading the pdf files to) with file name.


        if (in_array($extension, $allowedExts)) // Checking if file contains allowabale extensions.
        {
            if($size <= $maxSize) // Checking if the size of file is less than and equal to the maximum allowable upload size.
            {
                $moved = move_uploaded_file($_FILES['file']['tmp_name'], $webPath); // Moving the file to the path specified in $webPath variable.
                if($moved == true)
                {
                    $response['error'] = 0; // If moved successfully, storing 0 in the response array.
                    $response['path'] = $webPath; // Storing web path as path in the response array.
                    $response['filename'] = $filename; // Storing file name in the response array.
                }
                else 
             {
                    $response['error'] = 'internal'; // If move isn't successfull, return 'internal' to AJAX.
                }
            }
            else
            {
                 $response['error'] = 'size'; // If file size is too small or large, return 'size' to AJAX.
            }
        }
        else
        {
             $response['error'] = 'type'; // If file type is not that of defined, return 'type' to AJAX.
        }
        echo json_encode($response); // Returning the response in JSON format to AJAX.
    }
}

如果您需要进一步的帮助，请告诉我。 P.S：如果有效，请不要忘记将其标记为答案。