使用jquery更改向上和向下箭头

Question

Why won't this jQuery change my image to a down arrow like I want it to? When a user opens a drop down, the up arrow changes to a down arrow. I'm doing this with an if else because I don't know any easier way, but it's not working. The arrow stays up the entire time, no matter how many times I click. Here is the jQuery. Should be all thats needed. Thanks!

    $("h3#mpcClients").click(function() {
            $("#hidden0").slideToggle(500); 

            var up = true;

            if (up == true) {

            $("td h3").css("background-image", "url(http://www.crm-newsletter.com/client-emails/images/arrowDown.png)");
            up=false;
          }
            else if(up == false) {
                $("td h3").css("background-image", "url(http://www.crm-newsletter.com/client-emails/images/arrowUp.png)");
            up=true;
            }
            });

Answer 1

See .toggleClass() and set up some css like so:

.up {
    background-image: url("http://www.crm-newsletter.com/client-emails/images/arrowDown.png")
}
.down {
    background-image: url("http://www.crm-newsletter.com/client-emails/images/arrowDown.png")
}

Make sure you set up the html to a default arrow direction like so:

<td>
    <h3 class="up">Some text</h3>
</td>

Now for the js to change the css classes of the element:

$("h3#mpcClients").click(function() {
        $("#hidden0").slideToggle(500);

        // This adds a class if the element doesn't already have it
        // if the element already has the class it will remove it.
        $("td h3").toggleClass("up down"); 
});

Answer 2

Everytime the function is called it will set a var up to true. It will go into this clause everytime

    var up = true;

    if (up == true) {

    $("td h3").css("background-image", "url(http://www.crm-newsletter.com/client-emails/images/arrowDown.png)");
    up=false;
  }

Answer 3

<script type="text/javascript">
function slideT(id)
{   

    var n=id.split(" ");
    $('#panel'+n[1]).slideToggle('fastest');

    if(n[2]=='up')
    {
        $('#img'+n[1]).find('img').remove();

        $('#img'+n[1]).find('td').append('<img src="../images/down.png" id="'+n[0]+' '+n[1]+' down" style="float:left" onclick="slideT(this.id)" >');

    }
    else
    {
        $('#img'+n[1]).find('img').remove();
        $('#img'+n[1]).find('td').append('<img src="../images/up.png" id="'+n[0]+' '+n[1]+' up" style="float:left" onclick="slideT(this.id)" >');        
    }    
}
</script>

this answer will open ur table panel wich its HTML is sth like this:

<tr  style="cursor: pointer" id="img">
        <td align="center">&nbsp;<?=$value?><img src="../images/down.png" style="float: left;" id="slide>" onclick="slideT(this.id)"></td>
    </tr>

<table class="list_row_container" style="display: none;" id="panel">
</table>   

Answer 4

 $("h3#mpcClients").click(function() {
            $("#hidden0").slideToggle(500); 

            $("td h3").toggleClass('up');
});

In your css, by default add the rules for showing the down arrow and in a rule for .up set the background arrow image accordingly.

td h3 { background-image : url(http://www.crm-newsletter.com/client-emails/images/arrowDown.png);}

td h3.up { background-image : url(http://www.crm-newsletter.com/client-emails/images/arrowUp.png);}

Much neater.