upload_max_filesize = 300M
post_max_size = 300M

php_value upload_max_filesize "300M"
php_value post_max_size "300M"

$error=$myfile['myfile']['error'];
  if ($error==0){//為0，代表上傳成功
    if (move_uploaded_file($tmp,"userpic/".$picname)) {
      echo "移動(dòng)文件成功";
    }else{
      echo "移動(dòng)文件失敗";
    }
  }else{//不為0，匹配錯(cuò)誤信息
    switch ($error){
      case 1:
        echo "超過(guò)文件最大上傳限制";//php.ini中upload_max_filesize
        break;
      case 2:
        echo "超過(guò)表單文件大小限制";//HTML表單中MAX_FILE_SIZE選項(xiàng)
        break;
      case 3:
        echo "文件部分被上傳";
        break;
      case 4:
        echo "未選擇上傳文件";
        break;
      case 7://文件寫(xiě)入失敗
      case 8:
        echo "系統(tǒng)錯(cuò)誤";
        break;
    }
  }

<!--表單隱藏域?qū)ι蟼鞔笮∵M(jìn)行限制-->
<input type="hidden" name="MAX_FILE_SIZE" value="2097152">
<!--accept 對(duì)文件類(lèi)型限制-->
<input type="file" name="myfile" accept="image/jpeg,image/png">

$size=$myfile['size'];//獲取文件大小
$MaxSize=2097152;//設(shè)置最大允許字節(jié)
$type=$myfile['type'];//獲取圖片類(lèi)型
$AllowTypr=array('image/jpeg','image/png','image/gif');//允許類(lèi)型數(shù)組
if ($error==0){//為0，代表上傳成功
  if ($size>$MaxSize){
    echo "<script>alert('文件大小超過(guò)限制');</script>";
    echo "<script>history.back(1);</script>";
    exit();
  }
  if (!in_array($type,$AllowTypr)){
    echo "<script>alert('請(qǐng)上傳正確圖片類(lèi)型');</script>";
    echo "<script>history.back(1);</script>";
    exit();
  }