[Android] supportv4 fragment camera 問題

第一次使用supportv4 TabManager TabHost的功能來製作fragment分頁，在呼叫內建相機返回之後，有機率遇到java.lang.IllegalStateException: Fragment already added:的錯誤，網路上有很多相關討論，但感覺和此並沒有很相關。試了一陣子，發現原來是內建相機預設是橫向模式(landscape)，照出來的照片會自動轉+-90度，在返回fragment的時候，這照片有機會自己再轉-+90度，(即使手機的畫面旋轉關閉)，導致(個人猜測)supportv4誤判而再把fragment全部加回去，造成錯誤。

解決方法：因為此app只打算直式使用，所以manifest加入
<activity android:name="xxx.xxx.YourFragmentActivity"
            android:screenOrientation="portrait"
            android:configChanges="orientation|screenSize"/>

It's my first time to use the function of supportv4 TabManager TabHost to make fragments. When calling the camera and back to the fragment, the error "java.lang.IllegalStateException: Fragment already added:" may occurs. There are many discussion about this error, but few about this case. After trying for hours, I suppose the reason is: The default android camera is landscape. After taking a picture, the picture may automatically rotates +-90 degree(even the auto rotation is off). When back to a fragment, the picture rotates -+90 degree again. supportv4 may make a wrong decision to add all the fragment back and error occurs.

Solution：Since this app is design for portrait mode, add these in manifest
<activity android:name="xxx.xxx.YourFragmentActivity"
            android:screenOrientation="portrait"
            android:configChanges="orientation|screenSize"/>