Php html表单中的文件上载字段具有多个字段，仅对一个字段使用ajax

你好！ 我有一个困难的时间与我的html表单之一，它应该有一个上传图像的字段。 我想做的是能够选择一个文件（图像）并使用ajax将其发送到php文件，而无需提交整个表单。如何在主表单中为该文件类型添加其他表单

例如，我有一张表格：

<form action="submit.php" method="POST" >
<input type="text" name="title" />
<input type="text" name="descriptin" />
<input type="file" name="images" onchange="save_img()" id="file" />
</form>

但它不起作用。有人能帮我举个简单的例子吗？谢谢大家!

PHP代码：

<?php
define('AJAX_REQUEST', isset($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest');
if(!AJAX_REQUEST) {die();}
require_once("../classes/admin.Class.php");
// Checking nline status
$Admin = new Admin;
$Admin -> OnLine();
$link = 'www.'.$_SERVER['SERVER_NAME'];
$name = time().'-'.$_FILES['file']['name'];
$extension = strtolower(substr($name, strpos($name, '.') + 1));
$type = $_FILES['file']['type'];
$size = $_FILES['file']['size'];
$max_size = 20097152;
$tmp_name = $_FILES['file']['tmp_name'];
if(strlen($_FILES['file']['name'])>34)
    exit('Image name must contain less than 30 characters!');
if(isset($name)) {
    if(!empty($name)) {
        if(($extension=='jpg'||$extension=='jpeg')&&($type=='image/jpeg'||$type='image/jpg')&&$size<=$max_size) {
            //picture location
            $location = '../../upload/foto/';
            if(move_uploaded_file($tmp_name, $location.$name)) {
                $size = getimagesize($location.$name);
                if($size[0]>550){
                    $ratio = $size[0]/$size[1]; // width/height
                    if( $ratio > 1) {
                        $width = 550;
                        $height = 550/$ratio;
                    }
                    else {
                        $width = 550*$ratio;
                        $height = 550;
                    }
                    $new_image = imagecreatetruecolor($width,$height);
                    $image_source = imagecreatefromjpeg($location.$name);
                    imagecopyresampled($new_image, $image_source, 0, 0, 0, 0, $width, $height, $size[0], $size[1]);
                    imagejpeg($new_image,$location.$name,100);
                    imagedestroy($new_image);
                    imagedestroy($image_source);
                }
                $db = new Connect;
                $user_id = $db->prepare("SELECT id FROM vr_users WHERE id=:id");
                $user_id -> execute(array(
                    'id' => intval($_COOKIE['check'])
                ));
                $check = $user_id->fetch(PDO::FETCH_ASSOC);
                $user_id = $check['id'];
                $insert = $db->prepare("INSERT INTO vr_images SET id_post=0, link=:link, 
                id_user=:id_user");
                $insert -> execute(array(
                        'link'      => '/upload/foto/'.$name,
                        'id_user'   => $user_id
                ));
                echo "<div class='alerta_upload_index'><img src='/upload/ok.png' /><br/>Your image was uploaded successfully!<br />
                <strong>http://$link/upload/foto/$name</strong></div>";
                $images=$db->prepare("SELECT id, link FROM vr_images 
                WHERE id_user=:id_user AND id_post=:id_post ORDER BY id DESC");
                $images -> execute(array(
                        'id_user' => $user_id,
                        'id_post' => 0
                ));
                while ($check = $images->fetch(PDO::FETCH_ASSOC))
                {
                    $dimensiune = getimagesize('../../'.$check['link']);
                    echo "<div class='fisier_incarcat'>
                            <div class='info_fisier'>
                                $dimensiune[0] x $dimensiune[1] - <a onclick='delete_img(".$check['id'].");' style='cursor:pointer'>[x]</a>
                            </div>
                            <img style='width:auto;height:auto;max-width:100px;max-height:90px;' src='".$check['link']."' />
                        </div>";
                }
            } else {
                echo "Eroare";
            }
        } else {
            echo "<div class='alerta_upload_eroare'>Your file should be a jpg/jpeg picture and less than 2 MB!</div>";
        }
    } else {
        echo "Please, choose a file!";
    }
}else {
    echo "Error!";
}
?>

OnLine（）；
$link='www.$\u服务器['SERVER\u NAME']；
$name=time（）.'-'.$\文件['file']['name']；
$extension=strtolower（substr（$name，strpos（$name，'.'）+1））；
$type=$_文件['file']['type']；
$size=$_文件['file']['size']；
$max_size=20097152；
$tmp_name=$_FILES['file']['tmp_name']；
如果（strlen（$_FILES['file']['name']）>34）
退出（'图像名称必须包含少于30个字符！'）；
如果（isset（$名称））{
如果（！空（$name））{
如果（$extension=='jpg'| |$extension=='jpeg'）&&（$type=='image/jpeg'| |$type='image/jpg'）&&&$size550）{
$ratio=$size[0]/$size[1]；//宽度/高度
如果（$ratio>1）{
$width=550；
$height=550/$ratio；
}
否则{
$width=550*$ratio；
$height=550；
}
$new_image=imageCreateTureColor（$width，$height）；
$image\u source=imagecreatefromjpeg（$location.$name）；
imagecopyresampled（$new_image，$image_source，0,0,0，$width，$height，$size[0]，$size[1]）；
图像JPEG（$new_image，$location.$name，100）；
imagedestroy（$new_image）；
imagedestroy（$image\u source）；
}
$db=新连接；
$user\u id=$db->prepare（“从vr\u用户中选择id，其中id=：id”）；
$user\u id->执行（数组）(
'id'=>intval（$\u COOKIE['check']））
));
$check=$user\U id->fetch（PDO:：fetch\U ASSOC）；
$user_id=$check['id']；
$insert=$db->prepare（“插入到vr_图像集id_post=0，link=：link，
id_user=：id_user”）；
$insert->execute（数组）(
'link'=>'/upload/foto/'。$name，
'id\u user'=>$user\u id
));
echo“
您的图像已成功上载！

http://$link/upload/foto/$name”；
$images=$db->prepare（“选择id，从vr\U图像链接
其中id_user=：id_user和id_post=：id_post ORDER BY id DESC”）；
$images->execute（数组）(
'id\u user'=>$user\u id，
“id_post”=>0
));
而（$check=$images->fetch（PDO:：fetch_ASSOC））
{
$dimensune=getimagesize（“../../.”.$check['link']）；
回声“
$dimensune[0]x$dimensune[1]-[x]
";
}
}否则{
回声“爱神”；
}
}否则{
echo“您的文件应该是jpg/jpeg图片，并且小于2MB！”；
}
}否则{
echo“请选择一个文件！”；
}
}否则{
回声“错误！”；
}
?>

粘贴您的php代码我想了解如何将图像发送到我的php文件中，从那里我就可以开始了。非常感谢。在js上，在success函数中尝试console.log（JSON.stringify（data）），看看我们得到了什么。在调用AjaxNothing changed之前，还要对映像进行控制台日志。如何从该字段获取值？我使用var data=new FormData（）；每个（jQuery（'#file'）[0]。文件，函数（i，file）{data.append（'file-'+i，file）；}）；但它不明白。

<?php
define('AJAX_REQUEST', isset($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest');
if(!AJAX_REQUEST) {die();}
require_once("../classes/admin.Class.php");
// Checking nline status
$Admin = new Admin;
$Admin -> OnLine();
$link = 'www.'.$_SERVER['SERVER_NAME'];
$name = time().'-'.$_FILES['file']['name'];
$extension = strtolower(substr($name, strpos($name, '.') + 1));
$type = $_FILES['file']['type'];
$size = $_FILES['file']['size'];
$max_size = 20097152;
$tmp_name = $_FILES['file']['tmp_name'];
if(strlen($_FILES['file']['name'])>34)
    exit('Image name must contain less than 30 characters!');
if(isset($name)) {
    if(!empty($name)) {
        if(($extension=='jpg'||$extension=='jpeg')&&($type=='image/jpeg'||$type='image/jpg')&&$size<=$max_size) {
            //picture location
            $location = '../../upload/foto/';
            if(move_uploaded_file($tmp_name, $location.$name)) {
                $size = getimagesize($location.$name);
                if($size[0]>550){
                    $ratio = $size[0]/$size[1]; // width/height
                    if( $ratio > 1) {
                        $width = 550;
                        $height = 550/$ratio;
                    }
                    else {
                        $width = 550*$ratio;
                        $height = 550;
                    }
                    $new_image = imagecreatetruecolor($width,$height);
                    $image_source = imagecreatefromjpeg($location.$name);
                    imagecopyresampled($new_image, $image_source, 0, 0, 0, 0, $width, $height, $size[0], $size[1]);
                    imagejpeg($new_image,$location.$name,100);
                    imagedestroy($new_image);
                    imagedestroy($image_source);
                }
                $db = new Connect;
                $user_id = $db->prepare("SELECT id FROM vr_users WHERE id=:id");
                $user_id -> execute(array(
                    'id' => intval($_COOKIE['check'])
                ));
                $check = $user_id->fetch(PDO::FETCH_ASSOC);
                $user_id = $check['id'];
                $insert = $db->prepare("INSERT INTO vr_images SET id_post=0, link=:link, 
                id_user=:id_user");
                $insert -> execute(array(
                        'link'      => '/upload/foto/'.$name,
                        'id_user'   => $user_id
                ));
                echo "<div class='alerta_upload_index'><img src='/upload/ok.png' /><br/>Your image was uploaded successfully!<br />
                <strong>http://$link/upload/foto/$name</strong></div>";
                $images=$db->prepare("SELECT id, link FROM vr_images 
                WHERE id_user=:id_user AND id_post=:id_post ORDER BY id DESC");
                $images -> execute(array(
                        'id_user' => $user_id,
                        'id_post' => 0
                ));
                while ($check = $images->fetch(PDO::FETCH_ASSOC))
                {
                    $dimensiune = getimagesize('../../'.$check['link']);
                    echo "<div class='fisier_incarcat'>
                            <div class='info_fisier'>
                                $dimensiune[0] x $dimensiune[1] - <a onclick='delete_img(".$check['id'].");' style='cursor:pointer'>[x]</a>
                            </div>
                            <img style='width:auto;height:auto;max-width:100px;max-height:90px;' src='".$check['link']."' />
                        </div>";
                }
            } else {
                echo "Eroare";
            }
        } else {
            echo "<div class='alerta_upload_eroare'>Your file should be a jpg/jpeg picture and less than 2 MB!</div>";
        }
    } else {
        echo "Please, choose a file!";
    }
}else {
    echo "Error!";
}
?>