Android：UI控件Fragment、FragmentStack

Fragment的实现有两种方法：xml直接添加和通过代码添加。
下面xml中的<fragment和<RelativeLayout分别使用xml添加和代码添加：
XML代码：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".FragmentActivity" >
<fragment
android:id="@+id/fragment1"
android:name="com.example.aexh32_fragment.MyFragment"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView1"
android:layout_below="@+id/textView1"
android:layout_marginTop="52dp" />
<RelativeLayout
android:id="@+id/relayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
>
</RelativeLayout>
</RelativeLayout>

MyFragment类：（通过xml添加，直接新建一个Fragment类，从ui面板选择Fragment添加）

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebView.FindListener;
import android.widget.TextView;
public class MyFragment extends Fragment
{
//指定Fragment的layout，设置对应的控件事件
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View layout = inflater.inflate(R.layout.frangment_layout, null);
TextView textView = (TextView) layout.findViewById(R.id.textView1);

return layout;
}
}

FragmentActivity类：

import android.os.Bundle;
import android.app.Activity;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.view.Menu;
public class FragmentActivity extends android.support.v4.app.FragmentActivity //导入的必须是support.v4才能支持2.3
{
/**
* 两种方法:
* 1.xml可视化添加：
* 先写好Fragment类，添加对应类的Fragment控件
* 2.通过代码添加Fragment
*/

@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fragment);

//通过代码添加
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
MyFragment newFragment = new MyFragment();
ft.add(R.id.relayout, newFragment);//将MyFragment添加到relayout里
ft.commit();//add、remove、replace后，都需要commit提交一下
}
}

其他：
1.将fragment放入栈中

void addFragmentToStack()
{
mStackLevel++;
// Instantiate a new fragment.
Fragment newFragment = CountingFragment.newInstance(mStackLevel);
// Add the fragment to the activity, pushing this transaction
// on to the back stack.
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.simple_fragment, newFragment);

//下面两句是关键
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.addToBackStack(null);
ft.commit();
}

2.管理Fragment：
要在activity中管理fragment,需要使用FragmentManager. 通过调用activity的getFragmentManager()取得它的实例.
可以通过FragmentManager做一些事情, 包括:
1.使用findFragmentById()(用于在activity layout中提供一个UI的fragment)或findFragmentByTag()(适用于有或没有UI的fragment)获取activity中存在的fragment
2.将fragment从后台堆栈中弹出, 使用 popBackStack() (模拟用户按下BACK 命令).
3.使用addOnBackStackChangeListener()注册一个监听后台堆栈变化的listener.
参考资料:http://blog.csdn.net/aomandeshangxiao/article/details/7671533

3.fragment之间传递参数

传递参数的fragment：

FragmentTransaction ft = getActivity().getSupportFragmentManager().beginTransaction();
InfoFragment fragment = new InfoFragment();
Bundle bundle = new Bundle();
bundle.putInt(Contant.KEY_BUNDLE_POSITION, position);
fragment.setArguments(bundle);
ft.replace(R.id.list_fraglayout, fragment);
ft.setCustomAnimations(R.anim.slide_right_enter, R.anim.slide_left_out, R.anim.slide_left_in, R.anim.slide_right_exit);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.addToBackStack(null);
ft.commit();

接收参数的fragment:

int mId = getArguments().getInt(Contant.KEY_BUNDLE_POSITION);

4.找到对应Fragment

FragmentManager fm = getSupportFragmentManager();
Fragment fragment = (LoadRateTypeFragment) fm.findFragmentByTag(HBContant.FRAGMENT_TAG_LOADRATETYPE);
if (fragment == null)
{
fragment = new LoadRateTypeFragment();
fragment.setTargetFragment(fragment, 0);
fm.beginTransaction().add(fragment, HBContant.FRAGMENT_TAG_LOADRATETYPE).commit();
}