Question

我有以下FragmentActivity：

public class DiagramsActivity extends FragmentActivity implements TabListener, OnPageChangeListener {
    private ViewPager viewPager = null;
    private FragmentPagerAdapter fragmentPager = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        this.fragmentPager = new DiagramsFragmentPagerAdapter(this.getSupportFragmentManager());

        this.setContentView(R.layout.activity_diagrams); 

        this.viewPager = (ViewPager) this.findViewById(R.id.diagrams_pager);
        this.viewPager.setOnPageChangeListener(this);
        this.viewPager.setAdapter(this.fragmentPager);
        this.actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
        this.actionBar.addTab(actionBar.newTab().setText(this.getResources().getString(R.string.text_line)).setTabListener(this));
        this.actionBar.addTab(actionBar.newTab().setText(this.getResources().getString(R.string.text_bar)).setTabListener(this));
        this.actionBar.addTab(actionBar.newTab().setText(this.getResources().getString(R.string.text_scatter)).setTabListener(this));
        this.actionBar.addTab(actionBar.newTab().setText(this.getResources().getString(R.string.text_pie)).setTabListener(this));
    }

    @Override
    public void onTabSelected(Tab tab, FragmentTransaction fragmentTransaction) {
        this.viewPager.setCurrentItem(tab.getPosition());
    }

    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction fragmentTransaction) {}

    @Override
    public void onTabReselected(Tab tab, FragmentTransaction fragmentTransaction) {}

    @Override
    public void onPageScrollStateChanged(int state) {}

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {}

    @Override
    public void onPageSelected(int position) {
        this.actionBar.setSelectedNavigationItem(position);
    }
}

采用这种布局：

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/diagrams_pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000000"
    android:padding="10dip"
    tools:context="de.controller.activities.DiagramsActivity" >

</android.support.v4.view.ViewPager>

适配器：

public class DiagramsFragmentPagerAdapter extends FragmentPagerAdapter {

    public DiagramsFragmentPagerAdapter(FragmentManager fragmentManager) {
        super(fragmentManager);
    }

    @Override
    public Fragment getItem(int index) {
        switch (index) {
            case 0 : {
                return new LineFragment();
            } 
            case 1 : {
                return new BarFragment();
            } 
            case 2 : {
                return new ScatterFragment();
            }
            case 3 : {
                return new PieFragment();
            }
        }

        return null;
    }

    @Override
    public int getCount() {
        return 4;
    }
}

我有几个标签，例如以下内容：

public class LineFragment extends Fragment {
    private GraphicalView graphicalView = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        this.getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.activity_diagrams_line_fragment, container, false);
    }

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
    }

    @Override
    public void onResume() {
        super.onResume();

        if (this.graphicalView == null) {
            List<Double> xValues = Arrays.asList(1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0);
            List<Double> yValues = Arrays.asList(30.0, 34.0, 45.0, 57.0, 77.0, 89.0, 100.0, 111.0, 123.0, 145.0);

            this.graphicalView = new LineGraph().getLineGraph(this.getActivity().getApplicationContext(), xValues, yValues);

            LinearLayout layout = (LinearLayout) this.getActivity().findViewById(R.id.diagrams_line_layout);

            layout.addView(this.graphicalView, new LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, 500));
        } else {
            this.graphicalView.repaint();
        }
    }
}

我在此处创建的用于绘制图表的数据在onResume()内手动设置以进行测试。我现在要做的是创建/加载我想在我的FragmentActivity中表示的数据，我希望我的所有标签都使用FragmentActivity中的数据，并在{onResume时更新它1}}被调用。因为我需要在每个标签中有一个按钮，它启动用于选择数据的对话框。

如何在每个标签页面中创建一个对话框，将数据返回到FragmentActivity，之后更新新数据中的所有标签？

Answer 1

有两个直接的选择：

在您的片段getActivity()中使用onResume()来获取“父”活动的属性或“意图”
通过Fragment instantiation使用bundle和数据：

公共类DiagramsFragmentPagerAdapter扩展了FragmentPagerAdapter {

  @Override
  public Fragment getItem(int index) {
    Bundle b = new Bundle();
    b.putString( "someString", this.someString );
    b.putParcelable( "someObject", this.someObject() );
    switch (index) {
        case 0 : {
            return Fragment.instantiate( this, LineFragment.class.getName(), b );
    }
  }
}

使用父FragmentActivity中的数据创建片段选项卡

1 个答案: