[CodeIgniter] 解決 CI 下載函數 force_download 在 IE 底下檔案標題亂碼

CodeIgniter CodeIgniter 底下提供了 force_download 函數,讓使用者可以直接下載檔案,但是會遇到中文的問題,IE 底下開起來檔名會是亂碼,force_download(‘filename’, ‘data’) 如果 filename 使用中文,測試 FireFoxChrome 都是沒問題的,唯獨 IE 開起來就是有問題,所以麻煩請修改 helpers/download_helper.php 這隻程式。
if ( ! function_exists('force_download'))
{
	function force_download($filename = '', $data = '')
	{
		if ($filename == '' OR $data == '')
		{
			return FALSE;
		}

		// Try to determine if the filename includes a file extension.
		// We need it in order to set the MIME type
		if (FALSE === strpos($filename, '.'))
		{
			return FALSE;
		}
	
		// Grab the file extension
		$x = explode('.', $filename);
		$extension = end($x);

		// Load the mime types
		@include(APPPATH.'config/mimes'.EXT);
	
		// Set a default mime if we can't find it
		if ( ! isset($mimes[$extension]))
		{
			$mime = 'application/octet-stream';
		}
		else
		{
			$mime = (is_array($mimes[$extension])) ? $mimes[$extension][0] : $mimes[$extension];
		}
	
		// Generate the server headers
		if (strstr($_SERVER['HTTP_USER_AGENT'], "MSIE"))
		{
			header('Content-Type: "'.$mime.'"');
			header('Content-Disposition: attachment; filename="'.iconv('utf-8', 'big5', $filename).'"');
			header('Expires: 0');
			header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
			header("Content-Transfer-Encoding: binary");
			header('Pragma: public');
			header("Content-Length: ".strlen($data));
		}
		else
		{
			header('Content-Type: "'.$mime.'"');
			header('Content-Disposition: attachment; filename="'.$filename.'"');
			header("Content-Transfer-Encoding: binary");
			header('Expires: 0');
			header('Pragma: no-cache');
			header("Content-Length: ".strlen($data));
		}
	
		exit($data);
	}
}
裡面利用了 iconv 把 utf-8 編碼,改成 big5,這樣在 IE 底下就不會出現問題了
header('Content-Disposition: attachment; filename="'.iconv('utf-8', 'big5', $filename).'"');