PHP除開BOM頭後出現亂碼

PHP去除BOM頭後出現亂碼
程式用的是Notepad++文字編輯器編寫的，當選擇格式->以UTF-8格式編碼後，中文字元（從資料庫讀取，儲存到$_SESSION中）可以正常顯示，但是會出現以下警告

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at E:\wamp\www\biyesheji\login_check.php:1) in E:\wamp\www\biyesheji\login_check.php on line 1

Warning: Cannot modify header information - headers already sent by (output started at E:\wamp\www\biyesheji\login_check.php:1) in E:\wamp\www\biyesheji\login_check.php
Array ( [username] => 張三 [userid] => 2009011105 [role] => 3 )

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去掉BOM頭後，警告消失，但是中文字元全部變成亂碼

Array ( [username] => 寮犱笁 [userid] => 2009011105 [role] => 3 )
鐧誨綍鎴愬姛!
5縐掗挓鍚庤繘琛岃煩杞

求解決方案

------解決方案--------------------

header('Content-type: text/html; charset=utf-8');

加一句申明是UTF-8編碼，不然瀏覽器可能會自己去檢測

