Fragment

Fragment

>片段,碎片  

1. 定义某一个片段的界面 继承Fragment类
public class BlueToothFragment extends Fragment {}
2. 重写Fragment里面的方法
显示Fragment的ui,把布局文件转化成view对象
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.blue_tooth_layout, null);
}
3. 获取Fragment管理器
fm = getFragmentManager();
4. 动态的修改界面
f1 = new BlueToothFragment();//先把要显示的f1new出来
FragmentTransaction ft = fm.beginTransaction();//开启事务
ft.replace(R.id.fl_container, f1);

ft.commit();

activity_main布局

<LinearLayout 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:orientation="vertical"
    tools:context=".MainActivity" >

    <FrameLayout
        android:id="@+id/fl_container"
        android:layout_width="fill_parent"
        android:layout_weight="1"
        android:layout_height="0dip" >
    </FrameLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:background="#22000000"
        android:orientation="horizontal" >

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="setting01"
            android:text="蓝牙设置" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="setting02"
            android:text="声音设置" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="setting03"
            android:text="显示设置" />
    </LinearLayout>

</LinearLayout>

public class MainActivity extends Activity {
	private FragmentManager fm;
	BlueToothFragment f1;
	SoundFragment f2;
	ShowFragment f3;
	

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		fm = getFragmentManager();
		initFragment();
		//默认加载 BlueToothFragment 
		FragmentTransaction ft = fm.beginTransaction();//开启事务
		ft.replace(R.id.fl_container, f1);
		ft.commit();
	}

	private void initFragment() {
		f1 = new BlueToothFragment();
		f2 = new SoundFragment();
		f3 = new ShowFragment();
	}

	//--------------- 3个点击事件-------------------------
	//点击蓝牙
	public void setting01(View view) {
		FragmentTransaction ft = fm.beginTransaction();//这里要重新开启，不能在上面定义成成员
		ft.replace(R.id.fl_container, f1);
		ft.commit();
	}
	//点击声音
	public void setting02(View view) {
		FragmentTransaction ft = fm.beginTransaction();
		ft.replace(R.id.fl_container, f2);
		ft.commit();
	}
	//点击显示
	public void setting03(View view) {
		FragmentTransaction ft = fm.beginTransaction();
		ft.replace(R.id.fl_container, f3);
		ft.commit();
	}

}

public class BlueToothFragment extends Fragment {
	//显示Fragment的ui的
	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {
		return inflater.inflate(R.layout.blue_tooth_layout, null);
	}
}

Fragment的向下兼容
>使用support-v4的jar包
>1. MainActivity extends FragmentActivity
>2. 所有的fragment的导包, android.support.v4.app.Fragment
>3. getSupportFragmentManager();
>4. 注意两个导包
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;

public class MainActivity extends FragmentActivity {
	private FragmentManager fm;
	BlueToothFragment f1;
	ShowFragment f3;
	SoundFragment f2;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		//为了向下兼容采用v4包里面的FragmentManager
		fm = getSupportFragmentManager();
		initFragment();
		//事务的概念
		FragmentTransaction ft = fm.beginTransaction();
		ft.replace(R.id.fl_container, f1);
		ft.commit();//保证了 要么同时成功,要么同时失败
	}

	private void initFragment() {
		f1 = new BlueToothFragment();
		f2 = new SoundFragment();
		f3 = new ShowFragment();
	}

	
	public void setting01(View view) {
		FragmentTransaction ft = fm.beginTransaction();
		ft.replace(R.id.fl_container, f1);
		ft.commit();
	}
	
	public void setting02(View view) {
		FragmentTransaction ft = fm.beginTransaction();
		ft.replace(R.id.fl_container, f2);
		ft.commit();
	}
	
	public void setting03(View view) {
		
		FragmentTransaction ft = fm.beginTransaction();
		ft.replace(R.id.fl_container, f3);
		ft.commit();
	}

}