Php内容插入页面不工作

我一直在尝试用php制作一个内容插入页面，下面是我的代码

    <?php // Initialize variables to null.
$title =""; // Sender Name
$author =''; // Sender's email ID
$date =date('d-m-y'); // Subject of mail
$desc="";//meta description
$keywords="";//meta keywords
$content =""; // Sender's Message
$category="";//chosen category
$pattern1="";//preg_match pattern
$nameError ="";
$contentError ="";
$purposeError ="";
$messageError ="";
$successMessage =""; // On submittingform below function will execute.
$img_dir=$_SERVER["DOCUMENT_ROOT"] . '/practise/grafitti/images/';
$img;


if(isset($_POST['submit'])) { // Checking null values in message.
        //check and assign title title
        if(empty($_POST["title_post"])){
            $nameError = "A title is required";
             errors($nameError);
             exit();

        }
        else{
         if (preg_match("/^(\w|\s)$/",$_POST['title_post']))
        {
            $titleError = "Only letters,numbers and white space allowed";
            errors($titleError);

        }else{
          $title=$_POST['title_post'];
        }
        }


       // Checking null values inthe content.
        if (empty($_POST["content_post"]))
        {
            $contentError = "You have not posted any content.<br/> Please do to proceed";
            errors($contentError);
            exit();
        }else {
          $content=$_POST["content_post"];
        }

        //check and assign category
        if(!empty($_POST["categories_post"]))
         {
            $category=$_POST["categories_post"];
        }

        //Chexk and assign authors name
        if (!empty($_POST["author_post"]))
        {
        $author=$_POST["author_post"];
        }

        //check and assign value of description
        if (!empty($_POST["desc_post"]))
        {
        $desc=$_POST["desc_post"];
        }

        //check and assign keywords
        if (!empty($_POST["keywords_post"]))
        {
        $keywords=$_POST["keywords_post"];
        }

        //process images
        if(isset($_FILES["img_post"])){
          echo "good to go";
               $name=$_FILES["img_post"]["name"];
               $tmp_name=$_FILES["img_post"]["tmp_name"];
               $type=$_FILES["img_post"]["type"];
               $size=$_FILES["img_post"]["size"];
               $img_dir;

            if(upload($name,$type,$size,$tmp_name,$img_dir)){
                if(move_uploaded_file($tmp_name,$img_dir.$name)){
                    echo "success";
                }else{echo php_info;}

                $img_upload_Success="File was uploaded successfully";
               errors($img_upload_Success);

            }else{
               $img_upload_Error="File could not be uploaded";
               errors($img_upload_Error);
               exit();
            }
        }

         echo $title."<br/>";
         echo $author."<br/>";
         echo $desc."<br/>";
         echo $keywords."<br/>";
         echo $category."<br/>";
         echo $date."<br/>";
}

      // Function for filtering input values.function test_input($data)


         function errors($err){
        echo "<script>
         var err='$err'
        alert(err)
         </script>
          ";
         }

  #validate file upload
  function upload($fl_name,$fl_type,$fl_size,$fl_tmp_name,$dir){
     #check to see if the file is an image or not
      if($fl_type!="image/jpeg" && $fl_type!="image/png" && $fl_type!="image/jpg" && $fl_type!="image/gif"){
        $typeError="The file type you uploaded is not supported";
        errors($fl_type);
        exit();
        }

      #check file size limits
      if($fl_size>512000){
        $sizeError="Size of the file is too big. Should be at least 500KB";
        errors($sizeError);
        exit();
       }

      if(file_exists($dir.$fl_name)){
        $existError="Sorry. File already exists";
        errors($existError);
        exit();
      }
  }
?>

---

返回一个假值，但执行了上载（）。有人能告诉我如何处理isset问题，以及至少一种显示导致文件无法上载的错误的方法吗使用以下条件：

if($_FILES['img_post']['error'] == 0){
   //uplode file
}

这将检查它是空的还是文件已被选中。如果选中，则它将仅上载文件。

您可以尝试此操作

  if($_FILES['img_post']['error']==0) { 
  // process 
} else { 
  $error_message = $error_types[$_FILES['img_post']['error']]; 
  // do whatever with the error message 
} 

有关更多详细信息，请参阅。

更改此代码

if(isset($_FILES["img_post"])){

到

if(isset($_FILES["img_post"]["tmp_name"])){

使用以下代码：-

if(isset($_FILES["img_post"]["tmp_name"]) && $_FILES["img_post"]["tmp_name"] != ''){
   //uplode file
}

或

---

只需检查

$\u文件[“img\u post”][“tmp\u name”]！=“

与您的

isset（$\u文件[“img\u post”]）

。因此，如果（isset（$\u FILES[“img\u post”]）和&$\u FILES[“img\u post”][“tmp\u name”！=”）{。您好，您可以检查是否为文件组件设置了名称或tmp\u名称。\\u FILES[“img\u post”][“tmp\u name”]或$\u FILES[“img\u post”][“name”]。如果要检查上传成功与否，请检查文件[“img\u post”[“错误”]将返回状态，=0表示成功

$\u文件[“img\u post”]

所有文件都已工作，但文件仍无法上载。我认为问题可能是

upload（）

，因为

如果（upload（$name，$type，$size，$tmp\u name，$img\u dir））

返回错误结果

if(isset($_FILES["img_post"]["tmp_name"]) && $_FILES["img_post"]["tmp_name"] != ''){
   //uplode file
}

if(!empty($_FILES["img_post"]["tmp_name"])){
   //uplode file
}