如何修复此问题：
致命错误：在中的非对象上调用成员函数is_lock（）/home/u791507189/public_html/wp-content/plugins/private-messageing/app/views/shortcode/inbox_message.php在线12
这是代码：
<?php
$message = array_shift($messages);
if (!isset($render_reply)) {
$render_reply = true;
}
$conversation = MM_Conversation_Model::model()->find($message->conversation_id);
?>
<div class="ig-container">
<section class="message-content">
<div class="message-content-meta pull-left">
<?php do_action('message_content_meta', $message) ?>
<?php if ($conversation->is_lock()): ?> ***/////<----here is error////////***
<div class="clearfix"></div>
<span><?php _e("This conversation has been locked", mmg()->domain) ?></span>
<?php endif; ?>
</div>
<div class="message-content-actions pull-right">
<?php if (mmg()->get('box') != 'sent' && $render_reply == true): ?>
<?php
$from_data = get_userdata($message->send_from);
?>
<div class="btn-group btn-group-sm">
<?php if ($conversation->is_archive()): ?>
<a href="#" title="<?php echo esc_attr(__("Unarchive", mmg()->domain)) ?>"
data-id="<?php echo esc_attr(mmg()->encrypt($message->conversation_id)) ?>"
data-type="<?php echo MM_Message_Status_Model::STATUS_READ ?>"
class="btn btn-sm btn-default mm-status"><i class="fa fa-undo"></i></a>
<a href="#" title="<?php echo esc_attr(__("Delete", mmg()->domain)) ?>"
data-id="<?php echo esc_attr(mmg()->encrypt($message->conversation_id)) ?>"
data-type="<?php echo MM_Message_Status_Model::STATUS_DELETE ?>"
class="btn btn-sm btn-danger mm-status"><i class="fa fa-trash"></i></a>
<?php else: ?>
<?php if ($conversation->is_lock()): ?>
<button type="button" class="btn btn-info btn-sm" disabled>
<i class="fa fa-reply"></i>
</button>
<?php else: ?>
<a href="#reply-form-c"
data-username="<?php echo esc_attr($from_data->user_login) ?>"
data-parentid="<?php echo esc_attr(mmg()->encrypt($message->conversation_id)) ?>"
data-id="<?php echo esc_attr(mmg()->encrypt($message->id)) ?>" type="button"
class="btn btn-info btn-sm mm-reply">
<i class="fa fa-reply"></i>
</a>
<?php endif; ?>
<a href="#" title="<?php echo esc_attr(__("Archive", mmg()->domain)) ?>"
data-id="<?php echo esc_attr(mmg()->encrypt($message->conversation_id)) ?>"
data-type="<?php echo MM_Message_Status_Model::STATUS_ARCHIVE ?>"
class="btn btn-sm btn-default mm-status"><i class="fa fa-archive"></i></a>
<?php endif; ?>
</div>
<?php endif; ?>
<!--<button type="button" class="btn btn-danger btn-sm">
<i class="glyphicon glyphicon-trash"></i>
</button>-->
</div>
<?php /*$this->render_partial('shortcode/_reply_form', array(
'message' => $message
)); */ ?>
<div class="clearfix"></div>
<div class="page-header">
<h3 class="mm-message-subject"><?php echo apply_filters('mm_message_subject', $message->subject) ?></h3>
<div class="row">
<div class="col-md-12">
<div class="row">
<div class="col-md-3">
<img style="width: 100%;max-width: 100px" class="img-responsive img-circle center-block"
src="<?php echo mmg()->get_avatar_url(get_avatar($message->send_from)) ?>">
</div>
<div class="col-md-9">
<strong><?php
if ($message->send_from == get_current_user_id()) {
echo __("me", mmg()->domain) . ' (' . $message->get_name($message->send_from) . ')';
} else {
echo $message->get_name($message->send_from);
} ?></strong>
<div class="clearfix"></div>
<span><?php echo date('F j, Y, g:i a', strtotime($message->date)) ?></span>
<div class="clearfix"></div>
<?php if (mmg()->get('box') == 'sent'): ?>
<small><?php _e("To:", mmg()->domain) ?> <?php echo $message->get_name($message->send_to); ?></small>
<?php endif; ?>
</div>
</div>
</div>
<div class="clearfix"></div>
</div>
</div>
<div class="message-body">
<?php echo mmg()->html_beautifier(apply_filters('mm_message_content', $message->content)) ?>
</div>
<?php $ids = explode(',', $message->attachment);
$ids = array_filter($ids);
if (count($ids)):?>
<hr/>
<div class="message-footer">
<div class="row">
<?php foreach ($ids as $id): ?>
<?php $a_m = IG_Uploader_Model::model()->find($id); ?>
<div class="col-md-6 message-attachment">
<a class="load-attachment-info" data-target="<?php echo $id ?>" href="#">
<i class="fa fa-paperclip fa-2x pull-left"></i>
<?php echo $a_m->name ?> </a>
<div class="clearfix"></div>
<!-- Modal -->
<div class="modal" data-id="<?php echo $id ?>">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
<h4 class="modal-title"><?php echo $a_m->name ?></h4>
</div>
<div class="modal-body sample-pop" style="max-height:450px;overflow-y:scroll">
<?php
$file = $a_m->file;
//check does this file exist
$file_url = '';
$show_image = false;
if ($file) {
$file_url = wp_get_attachment_url($file);
$mime = explode('/', get_post_mime_type($file));
if (array_shift($mime) == 'image') {
$show_image = true;
}
}
if ($show_image) {
echo '<img src="' . $file_url . '"/>';
} elseif ($file) {
//show meta
?>
<ul class="list-group">
<li class="list-group-item upload-item">
<i class="glyphicon glyphicon-floppy-disk"></i>
<?php _e('Size', mmg()->domain) ?>:
<strong><?php
$tfile = get_attached_file($file);
//check does this files has deleted
if ($tfile) {
$size = @filesize($tfile);
echo $size === false ? 'N/A' : $size;
} else {
echo __("N/A", mmg()->domain);
}
?></strong>
</li>
<li class="list-group-item upload-item">
<i class="glyphicon glyphicon-file"></i>
<?php _e('Type', mmg()->domain) ?>:
<strong><?php echo ucwords(get_post_mime_type($file)) ?></strong>
</li>
</ul>
<?php
} else {
?>
<ul class="list-group">
<li class="list-group-item">
<i class="glyphicon glyphicon-link"></i>
<strong><?php _e('Link', mmg()->domain) ?></strong>:
<?php echo $a_m->url ?>
</li>
<div class="clearfix"></div>
</ul>
<?php
} ?>
</div>
<div class="modal-footer">
<?php if ($a_m->url): ?>
<a class="btn btn-info" rel="nofollow"
href="<?php echo esc_attr($a_m->url) ?>" target="_blank">
<?php _e("Visit Link", mmg()->domain) ?>
</a>
<?php endif; ?>
<?php if ($a_m->file): ?>
<a href="<?php echo $file_url ?>" download
class="btn btn-info"><?php _e('Download File', mmg()->domain) ?></a>
<?php endif; ?>
<button type="button" class="btn btn-default attachment-close"
data-dismiss="modal">Close
</button>
</div>
</div>
</div>
</div>
</div>
<?php endforeach; ?>
<div class="clearfix"></div>
</div>
</div>
<?php endif; ?>
</section>
<!--render history-->
<?php if (is_array($messages) && count($messages)): ?>
<div class="well well-sm no-margin">
<?php foreach ($messages as $key => $message): ?>
<section class="message-content">
<div class="page-header">
<h3 class="mm-message-subject"><?php echo apply_filters('mm_message_subject', $message->subject) ?></h3>
<div class="row">
<div class="col-md-12">
<div class="row">
<div class="col-md-3">
<img style="max-width:100px;width: 100%"
class="img-responsive img-circle center-block"
src="<?php echo mmg()->get_avatar_url(get_avatar($message->send_from)) ?>">
</div>
<div class="col-md-9">
<strong><?php echo $message->get_name($message->send_from) ?></strong>
<div class="clearfix"></div>
<span><?php echo date('F j, Y, g:i a', strtotime($message->date)) ?></span>
<div class="clearfix"></div>
<?php if (mmg()->get('box') == 'sent'): ?>
<small><?php _e("To:", mmg()->domain) ?> <?php echo $message->get_name($message->send_to) ?></small>
<?php endif; ?>
</div>
</div>
</div>
<div class="clearfix"></div>
</div>
</div>
<div class="message-body">
<?php echo mmg()->html_beautifier(apply_filters('mm_message_content', $message->content)) ?>
</div>
<?php $ids = explode(',', $message->attachment);
$ids = array_filter($ids);
if (count($ids)):?>
<hr/>
<div class="message-footer">
<div class="row">
<?php foreach ($ids as $id): ?>
<?php $a_m = IG_Uploader_Model::model()->find($id); ?>
<div class="col-md-6 message-attachment">
<a class="load-attachment-info" data-target="<?php echo $id ?>" href="#">
<i class="fa fa-paperclip fa-2x pull-left"></i>
<?php echo $a_m->name ?> </a>
<div class="clearfix"></div>
<!-- Modal -->
<div class="modal" data-id="<?php echo $id ?>">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
<h4 class="modal-title"><?php echo $a_m->name ?></h4>
</div>
<div class="modal-body sample-pop"
style="max-height:450px;overflow-y:scroll">
<?php
$file = $a_m->file;
//check does this file exist
$file_url = '';
$show_image = false;
if ($file) {
$file_url = wp_get_attachment_url($file);
$mime = explode('/', get_post_mime_type($file));
if (array_shift($mime) == 'image') {
$show_image = true;
}
}
if ($show_image) {
echo '<img src="' . $file_url . '"/>';
} elseif ($file) {
//show meta
?>
<ul class="list-group">
<li class="list-group-item upload-item">
<i class="glyphicon glyphicon-floppy-disk"></i>
<?php _e('Size', mmg()->domain) ?>:
<strong><?php
$tfile = get_attached_file($file);
//check does this files has deleted
if ($tfile) {
$size = @filesize($tfile);
echo $size === false ? 'N/A' : $size;
} else {
echo __("N/A", mmg()->domain);
}
?></strong>
</li>
<li class="list-group-item upload-item">
<i class="glyphicon glyphicon-file"></i>
<?php _e('Type', mmg()->domain) ?>:
<strong><?php echo ucwords(get_post_mime_type($file)) ?></strong>
</li>
</ul>
<?php
} else {
?>
<ul class="list-group">
<li class="list-group-item">
<i class="glyphicon glyphicon-link"></i>
<strong><?php _e('Link', mmg()->domain) ?></strong>:
<?php echo $a_m->url ?>
</li>
<div class="clearfix"></div>
</ul>
<?php
} ?>
</div>
<div class="modal-footer">
<?php if ($a_m->url): ?>
<a class="btn btn-info" rel="nofollow"
href="<?php echo esc_attr($a_m->url) ?>" target="_blank">
<?php _e("Visit Link", mmg()->domain) ?>
</a>
<?php endif; ?>
<?php if ($a_m->file): ?>
<a href="<?php echo $file_url ?>" download
class="btn btn-info"><?php _e('Download File', mmg()->domain) ?></a>
<?php endif; ?>
<button type="button" class="btn btn-default attachment-close"
data-dismiss="modal">Close
</button>
</div>
</div>
</div>
</div>
</div>
<?php endforeach; ?>
<div class="clearfix"></div>
</div>
</div>
<?php endif; ?>
</section>
<?php endforeach; ?>
</div>
<?php endif; ?>
</div>
<script type="text/javascript">
jQuery(document).ready(function ($) {
$('.mm-reply').leanModal({
closeButton: ".compose-close",
top: '5%',
width: '90%',
maxWidth: 659
});
/*$('.load-attachment-info').leanModal({
closeButton: '.attachment-close',
top: '5%',
width: '90%',
maxWidth: 659
});*/
})
</script>
问题是$conversation是一个对象，它没有任何方法。
您应该审阅，文档中返回的MM_Conversation_Model::model()->find($message->conversation_id);是什么。