未显示Javascript消息

Question

我正试图将用户个人资料图片的数据插入数据库。该功能工作正常，但问题是通知用户的消息没有显示任何内容。我已经附上了下面的控制器代码，因为我正在使用代码点火器。

function fresherImageStore()  
{  
if (isset($_FILES["image_file"]["name"]))  
{  
$user = $this->session->userdata('fresher_id');
$config['upload_path'] = './uploads/fresherimages';  
$config['allowed_types'] = 'jpg|jpeg|png|gif';  
$this->load->library('upload', $config);  
if (!$this->upload->do_upload('image_file'))  
{  
$error =  $this->upload->display_errors(); 
echo json_encode(array('msg' => $error, 'success' => false));
}  
else 
{  
$user = $this->session->userdata('fresher_id');
$data = array('upload_data' => $this->upload->data());
$data1 = array(
'user' => $user,
'name' => $data['upload_data']['file_name']
);  
$query = $this->db->get_where('images',array('user'=>$user));
if ($query->num_rows() > 0) {
$this->db->set('name',$data['upload_data']['file_name'])
->where('user',$user)
->update('images');        
$arr = array('msg' => 'Your image has been uploaded successfully', 'success' => true);
}
else
{
$this->db->insert('images',$data1);
$getId = $this->db->insert_id();
$arr = array('msg' => 'Image has not uploaded successfully', 'success' => false);
if ($getId) {
$arr = array('msg' => 'Image has been uploaded successfully', 'success' => true);
}
echo json_encode($arr);
}  
}  
}
} 

那么这就是html

<form method="POST" id="upload_form" enctype="multipart/form-data">  
<div class="col-md-7">
<h3> Upload your photo</h3></br>
<div id="divMsg" class="alert alert-success" style="display: none">
<span id="ms"></span>
</div>
<input type="file" name="image_file" multiple="true" accept="image/*" id="finput" onchange="readURL(this);"></br></br>
<button class="btn btn-success">Submit</button>
</div>
<div class="col-md-5"></div>

最后是jquery函数

$(document).ready(function(){  
$('#upload_form').on('submit', function(e){  
e.preventDefault();  
if($('#image_file').val() == '')  
{  
alert("Please Select the File");  
}  
else 
{  
$.ajax({  
url:"<?php echo base_url(); ?>images/seekerImageStore",   
method:"POST",  
data:new FormData(this),  
contentType: false,  
cache: false,  
processData:false,  
dataType: "json",
success:function(res)  
{  
console.log(res.success);
if(res.success == true){
$('#blah').attr('src','//www.tutsmake.com/ajax-image-upload-with-preview-in-codeigniter/');   
$('#msg').html(res.msg1);   
$('#divMsg').show();   
}
else if(res.success == false){
$('#msg').html(res.msg); 
$('#divMsg').show(); 
}
setTimeout(function(){
$('#msg').html('');
$('#divMsg').hide(); 
}, 3000);
}  
});  
}  
});  

Answer 1

您的jQuery代码正试图将消息附加到id为msg的元素上，但消息应该指向的span标记被称为ms。

如果你查看浏览器的控制台，你会看到错误。您指向的是一个不存在的ID

Answer 2

您不会收到任何关于"成功"的消息，因为当遇到这种情况时，您不会发送任何json。

只需从嵌套if/else:中取出takeecho json_encode($arr);

if ($query->num_rows() > 0) {
$this->db->set('name',$data['upload_data']['file_name'])
->where('user',$user)
->update('images');        
$arr = array('msg' => 'Your image has been uploaded successfully', 'success' => true);
}
else
{
$this->db->insert('images',$data1);
$getId = $this->db->insert_id();
$arr = array('msg' => 'Image has not uploaded successfully', 'success' => false);
if ($getId) {
$arr = array('msg' => 'Image has been uploaded successfully', 'success' => true);
}   
}  
echo json_encode($arr);

然后在您的视图中(ajax成功(，您可以输出如下消息：

$('#divMsg').show().find('span').html(res.msg);