android片段是否可重用?

时间:2012-04-26 17:59:20

标签: java android android-fragments

Android片段是否可重用 - 我的意思是如果我可以使用如下代码:

class MyTabActivity extends FragmentActivity implements OnClickListener {

    Fragment[] tabs = new Fragment[3];

    @Override
    protected void onCreate(Bundle bundle) {
        super.onCreate(bundle);
        setContentView(R.layout.settings_activity);
        findViewById(R.id.button1).setOnClickListener(this);
        findViewById(R.id.button2).setOnClickListener(this);
        findViewById(R.id.button3).setOnClickListener(this);

        //first xml-defined fragment, it is inside  
        //FrameLayout with id R.id.loadTarget -> see openTab()
        tabs[0] = getSupportFragmentManager().findFragmentById(
                R.id.firstFragment);
    }

    private void openTab(int i) {
        final FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        ft.replace(R.id.loadTarget, getTabFragment(i));
        ft.addToBackStack(null);
        ft.commit();
    }

    private Fragment getTabFragment(int i) {
        if(tabs[i] == null) {
            switch(i) {

                //0-tab fragment has been allready 
                //retrieved in onCreate

                case 1:
                    tabs[1] = new MySecondTabFragment();
                    break;
                case 2:
                    tabs[2] = new MyThirdTabFragment();
                    break;
            }
        }
        return tabs[i];
    }

    @Override
    public void onClick(View v) {
        switch(v.getId()) {
            case R.id.button1:
                openTab(0);
                break;
            case R.id.button2:
                openTab(1);
                break;
            case R.id.button3:
                openTab(2);
                break;
        }
    }
}

1 个答案:

答案 0 :(得分:0)

是片段是可重复使用的,您可以多次将片段附加/分离到活动。正如您在分离后在文档中看到的那样,片段被销毁,然后在添加到另一个活动时再次创建。