Magento Set Multiple Currencies - magento

Question

I have a problem with Magento currency: My code is working fine otherwise, now I want to redirect the page after a change of currency.
Suppose my current URL is http://www.example.com/women/?color=black.
Now, When I change currency it will redirect to: http://www.example.com/women/; so it removes ?color=black.
Code:
if($this->getCurrencyCount()>1): ?>
<div class="block block-currency">
<div class="block-title">
<strong><span><?php echo $this->__('Select Your Currency') ?></span></strong>
</div>
<div class="block-content">
<select name="currency" title="<?php echo $this->__('Select Your Currency') ?>" onchange="setLocation(this.value)">
<?php foreach ($this->getCurrencies() as $_code => $_name): ?>
<option value="<?php echo $this->getSwitchCurrencyUrl($_code) ?>"<?php if($_code==$this->getCurrentCurrencyCode()): ?> selected="selected"<?php endif; ?>>
<?php echo $_name ?> - <?php echo $_code ?>
</option>
<?php endforeach; ?>
</select>
</div>
</div>
<?php endif;
Updated Code:
<?PHP $currentParams = $this->getRequest()->getParams(); ?>
<div style="float:left; margin-top:10px; color:#727478;">
<!--Change 1 to 0 if you wish to output selector always-->
<?php if($this->getCurrencyCount() > 1): ?>
<span>Select Currency:</span>
<select name="custom-currency-selector" id="custom-currency-selector">
<?php foreach ($this->getCurrencies() as $_code => $_name):
$currencyUrl = $this->getSwitchCurrencyUrl($_code);
foreach ($currentParams as $_param) {
$currencyUrl = $this->helper('core/url')->addRequestParam($currencyUrl, $_param);
}
?>
<option value="<?php echo $currencyUrl; ?>"
<?php if($_code == $this->getCurrentCurrencyCode()): ?>
selected="SELECTED"
<?php endif; ?>>
<?php echo $_code ?>
</option>
<?php endforeach; ?>
</select>
<?php endif;?>
Updated Code:
<!--Change 1 to 0 if you wish to output selector always-->
<?php if($this->getCurrencyCount() > 1):
$currentParams = $this->getRequest()->getParams();
?>
<span>Select Currency:</span>
<select name="custom-currency-selector" id="custom-currency-selector">
<?php foreach ($this->getCurrencies() as $_code => $_name):
$currencyUrl = $this->helper('core/url')->addRequestParam($this->getSwitchCurrencyUrl($_code),$currentParams)
?>
<option value="<?php echo $currencyUrl ?>"
<?php if($_code == $this->getCurrentCurrencyCode()): ?>
selected="SELECTED"
<?php endif; ?>>
<?php echo $_code ?>
</option>
<?php endforeach; ?>
</select>
<?php endif; ?>

Answer 1

You should add these params to the new url:
$currentParams = $this->getRequest()->getParams();
$currencyUrl = $this->helper('core/url')->addRequestParam(
$this->getSwitchCurrencyUrl($_code),
$currentParams
)
Then use $currencyUrl as url for redirect.