FrameLayout和Fragment处理Android应用UI布局实例
将fragment与layout结合使用,一般都是主activity以frame填充activity的方式交互管理fragment :
1.由于用到getsupportfragmentmanager()之类,所以主activity的extends需为fragmentactivity:
public class mainactivity extends fragmentactivity{ .......... }
2.主activity的layout(xml文件)中建立多个frame并定义其android:id="@+id/xxx"
3.主activity内操作函数中,由查找id来对这些framelayout进行activity填充:
添加语句如下
getsupportfragmentmanager().begintransaction().add(r.id.fragment_container2,new nullfrag()).commit();
取得支持fragment管理()->开始交易()->添加(frame的id , fragment).交付();
替换语句如下
getsupportfragmentmanager().begintransaction().replace(r.id.fragment_container2,new nullfrag()).commit();
取得支持fragment管理()->开始交易()->替代(frame的id , fragment).交付();
例:
public void click_btn_flag02(view view){
getsupportfragmentmanager().begintransaction().replace(r.id.fragment_container2,new midfrag()).commit();
}
注:函数参数要用view
下面我们来看实例:
效果图的左边是一个列表,右边是列表item的详情。
先看一下布局文件(layout):
<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="match_parent"> <fragment class="com.fragment.main.titlesfragment" android:id="@+id/titles" android:layout_weight="1" android:layout_width="0px" android:layout_height="match_parent" /> <framelayout android:id="@+id/details" android:layout_weight="1" android:layout_width="0px" android:layout_height="match_parent" android:background="?android:attr/detailselementbackground" /> </linearlayout>
布局文件中使用了fragment标签和framelayout标签。android fragment使用 中介绍了2中嵌入fragment的方法,这个实例中都用到,从布局文件看到有了fragment标签,这是一种使用方法,framelayout标签将会成为第二种加载fragment的载体view。
看一下程序实现(com.fragment.main.titlesfragment):
public class titlesfragment extends listfragment { int mcurcheckposition = 0; int mshowncheckposition = -1; @override public void onactivitycreated(bundle savedinstancestate) { super.onactivitycreated(savedinstancestate); setlistadapter(new arrayadapter<string>(getactivity(), android.r.layout.simple_list_item_activated_1, shakespeare.titles)); //使用静态数组填充列表 if (savedinstancestate != null) { mcurcheckposition = savedinstancestate.getint("curchoice", 0); mshowncheckposition = savedinstancestate.getint("shownchoice", -1); } getlistview().setchoicemode(listview.choice_mode_single); showdetails(mcurcheckposition); } @override public void onsaveinstancestate(bundle outstate) { super.onsaveinstancestate(outstate); outstate.putint("curchoice", mcurcheckposition); outstate.putint("shownchoice", mshowncheckposition); } @override public void onlistitemclick(listview l, view v, int position, long id) { showdetails(position); } /** *显示listview item 详情 */ void showdetails(int index) { mcurcheckposition = index; getlistview().setitemchecked(index, true); if (mshowncheckposition != mcurcheckposition) { detailsfragment df = detailsfragment.newinstance(index); fragmenttransaction ft = getfragmentmanager() .begintransaction(); ft.replace(r.id.details, df); ft.settransition(fragmenttransaction.transit_fragment_fade); ft.commit(); mshowncheckposition = index; } } }
titlesfragment
titlesfragment继承自fragment的子类listfragment,使用了一个静态数组填充列表,重写了onlistitemclick方法,showdetails方法展示listview item的详情。
detailsfragment df = detailsfragment.newinstance(index);//获取详情fragment的实例 fragmenttransaction ft = getfragmentmanager().begintransaction();//获取fragmenttransaction 实例 ft.replace(r.id.details, df); //使用detailsfragment 的实例 ft.settransition(fragmenttransaction.transit_fragment_fade); ft.commit();//提交
看一下detailsfragment :
public class detailsfragment extends fragment { /** * create a new instance of detailsfragment, initialized to * show the text at 'index'. */ public static detailsfragment newinstance(int index) { detailsfragment f = new detailsfragment(); // supply index input as an argument. bundle args = new bundle(); args.putint("index", index); f.setarguments(args); return f; } @override public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) { if (container == null) { return null; } scrollview scroller = new scrollview(getactivity()); textview text = new textview(getactivity()); int padding = (int) typedvalue.applydimension( typedvalue.complex_unit_dip, 4, getactivity().getresources() .getdisplaymetrics()); text.setpadding(padding, padding, padding, padding); scroller.addview(text); text.settext(shakespeare.dialogue[getarguments().getint("index", 0)]); return scroller; } }
detailsfragment 中使用newinstance(int index)方法产生detailsfragment 实例并接受整型参数,重载了oncreateview方法创建view。
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