重复创建fragment的解决办法

直接上代码：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {    private FrameLayout mFrameLayout;    private Button btn_pan;    private Button btn_twopan;    private Button btn_sanpan;    private Button btn_sipan;    private List<Fragment> mFragments = new ArrayList<>();    private PanFragment panFragment;    private TwoPanFragment twoPanFragment;    private SanFragment sanPanFragment;    private SiPanFragment siPanFragment;    Fragment currentFragment = new Fragment();    private int currentPostion;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();        initListener();        panFragment = new PanFragment();        twoPanFragment = new TwoPanFragment();        sanPanFragment = new SanFragment();        siPanFragment = new SiPanFragment();        mFragments.add(panFragment);        mFragments.add(twoPanFragment);        mFragments.add(sanPanFragment);        mFragments.add(siPanFragment);        setLayout();    }    private void initListener() {        btn_pan.setOnClickListener(this);        btn_twopan.setOnClickListener(this);        btn_sanpan.setOnClickListener(this);        btn_sipan.setOnClickListener(this);    }    private void initView() {        mFrameLayout = (FrameLayout) findViewById(R.id.fl_fragment);        btn_pan = (Button) findViewById(R.id.btn_pan);        btn_twopan = (Button) findViewById(R.id.btn_twopan);        btn_sanpan = (Button) findViewById(R.id.btn_sanpan);        btn_sipan = (Button) findViewById(R.id.btn_sipan);    }//主要方法    private void setLayout() {        FragmentManager manger = getSupportFragmentManager();        FragmentTransaction transaction = manger.beginTransaction();        if (!mFragments.get(currentPostion).isAdded()) {            transaction.hide(currentFragment).add(R.id.fl_fragment, mFragments.get(currentPostion));        } else {            transaction.hide(currentFragment).show(mFragments.get(currentPostion));        }        currentFragment = mFragments.get(currentPostion);        transaction.commit();    }//    private void setLayout1(Fragment from, Fragment to) {        if (from != to) {            FragmentManager manger = getSupportFragmentManager();            FragmentTransaction transaction = manger.beginTransaction();            if (!to.isAdded()) {                if (from != null) {                    transaction.hide(from);                }                if (to != null) {                    transaction.add(R.id.fl_fragment, to).commit();                }            } else {                if (from != null) {                    transaction.hide(from);                }                if (to != null) {                    transaction.show(to).commit();                }            }        }    }    @Override    public void onClick(View v) {        switch (v.getId()) {            case R.id.btn_pan:                currentPostion = 0;                break;            case R.id.btn_twopan:                currentPostion = 1;                break;            case R.id.btn_sanpan:                currentPostion = 2;                break;            case R.id.btn_sipan:                currentPostion = 3;                break;        }        setLayout();    }}

结果：

07-11 07:57:56.996 10077-10077/com.jetway.fenping D/SiPanFragment: onCreateView: 
07-11 07:57:58.660 10077-10077/com.jetway.fenping D/SanFragment: onCreateView: 
07-11 07:57:59.860 10077-10077/com.jetway.fenping D/TwoPanFragment: onCreateView: （日志没有重复创建）