Android Fragment-（一）

话不多说直接上代码：

MainActivity
public class MainActivity extends FragmentActivity implements View.OnClickListener{    PRivate Button button1,button2,button3,button4;    private FrameLayout framelayout;    private FragmentManager fm;    private OneFragment onef;    private BlankFragment twof;    private  FourFragment threef;    protected void onCreate(@Nullable Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        createid();        fm=getSupportFragmentManager();    }    private void createid() {        button1= (Button) findViewById(R.id.button1);        button2= (Button) findViewById(R.id.button2);        button3= (Button) findViewById(R.id.button3);        button4= (Button) findViewById(R.id.button4);        framelayout= (FrameLayout) findViewById(R.id.Fragmentlayout);//        点击事件        button1.setOnClickListener(this);        button2.setOnClickListener(this);        button3.setOnClickListener(this);        button4.setOnClickListener(this);    }    @Override    public void onClick(View view) {//        开启事务        FragmentTransaction fmt=fm.beginTransaction();//        首先隐藏fragment        hidefragment(fmt);        if(view.getId()==R.id.button1){        if (onef==null){            onef=new OneFragment();            fmt.add(R.id.Fragmentlayout,onef);}        else{            fmt.show(onef);        }    }        if(view.getId()==R.id.button2){            if (twof==null){                twof=new BlankFragment();                fmt.add(R.id.Fragmentlayout,twof);}            else{                fmt.show(twof);            }        }        if(view.getId()==R.id.button3){            if (threef==null){                threef=new FourFragment();                fmt.add(R.id.Fragmentlayout,threef);}            else{                fmt.show(threef);            }        }        if (view.getId()==R.id.button4){            Log.e("button4","你还需要努力");        }        fmt.commit();    }    private void hidefragment(FragmentTransaction fmt) {        if (onef!=null){            fmt.hide(onef);        }        if (twof!=null){            fmt.hide(twof);        }        if (threef!=null){            fmt.hide(threef);        }    }}
主界面的xml：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main"    android:layout_width="match_parent" android:layout_height="match_parent"    android:orientation="vertical"    >    <FrameLayout        android:id="@+id/Fragmentlayout"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_weight="1">    </FrameLayout>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_weight="5"       >        <Button            android:id="@+id/button1"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_weight="1"            android:text="Button1"/>        <Button            android:id="@+id/button2"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_weight="1"            android:text="Button2"/>        <Button            android:id="@+id/button3"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_weight="1"            android:text="Button3"/>        <Button            android:id="@+id/button4"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_weight="1"            android:text="Button4"/>    </LinearLayout></LinearLayout>
OneFragment ：
public class OneFragment extends Fragment {    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container,                             Bundle savedInstanceState) {        // Inflate the layout for this fragment        return inflater.inflate(R.layout.fragment_one, container, false);    }其他的Fragment和一样。
fragment的XML：
<TextView    android:layout_width="match_parent"    android:layout_height="match_parent"    android:text="这是第一个" />