thinkPHP 框架下 導出excel

public function exportSN(){
       
		//$objReader = PHPExcel_IOFactory::createReader('Excel5');
		header("Content-Type: text/html; charset=utf-8");
		header("Content-type:application/vnd.ms-execl");
		header("Content-Disposition:filename=彙總.xls");
        
		//   如下\t表明橫向跨越一格，\n 表明跳到下一行，能夠根據本身的要求，增長相應的輸出相，要和循環中的對應哈
		//字段
		$letterArr=explode(',',strtoupper('a,b,c,d,e,f,g'));
		$arr=array(
    		array('en'=>'sn','cn'=>'SN碼(中獎號)'),
    		array('en'=>'prize','cn'=>'獎項'),
    		array('en'=>'sendstutas','cn'=>'是否已發獎品'),
    		array('en'=>'sntime','cn'=>'獎品發送時間'),
    		array('en'=>'openid','cn'=>'openid'),
    		array('en'=>'name','cn'=>'中獎者微信碼'),
    		array('en'=>'prizedate','cn'=>'中獎時間'),
		);
		$chengItem=array('piaomianjia','shuifei','yingshoujine','yingfupiaomianjia','yingfushuifei','yingfujine','dailishouru','fandian','jichangjianshefei','ranyoufei');

		$i=0;
		$fieldCount=count($arr);
		$s=0;
		//thead
		foreach ($arr as $f){
			if ($s<$fieldCount-1){
			    echo $f['cn']."\t";
				// echo iconv('gbk','utf-8',$f['cn'])."\t";//thinkphp無需轉utf－8
			}else {
			    echo $f['cn']."\n";
// 				echo iconv('gbk','utf-8',$f['cn'])."\n";
			}
				
			$s++;
		}
	
		$db=M('AddonAutumns_box');
		$id=intval($_GET['id']);
		$sns=$db->where(array('bid'=>$id,'isprize'=>1))->order('id ASC')->select();
		if ($sns){
			
			foreach($sns as $key=>$val){
			$user =  M('User')->where(array('openid'=>$val['wecha_id']))->field('username,openid')->find();
				$sns[$key]['openid'] = $user['openid'];
				$sns[$key]['name'] = $user['username'];
			}
			foreach ($sns as $sn){
				$j=0;
				foreach ($arr as $field){
					$fieldValue=$sn[$field['en']];
					switch ($field['en']){
						default:
							break;
						case 'time':
						case 'sntime':
							if ($fieldValue){
								$fieldValue=date('Y-m-d H:i:s',$fieldValue);
							}else {
								$fieldValue='';
							}
							break;
						case 'name':
						case 'prize':
				// 			$fieldValue=iconv('gbk','utf-8',$fieldValue);
							break;
					}
					if ($j<$fieldCount-1){
					    
						echo $fieldValue."\t";
					}else {
						echo $fieldValue."\n";
					}
					$j++;
				}
				$i++;
			}
		}
	
		exit();
	}