Question

忍受我，这是我的第一个Android应用程序我需要帮助将arraylist（n）从片段转移到另一个（frag1到frag2）。我读了关于捆绑和接口但我无法实现这些解决方案。任何详细的解决方案都会有所帮助。

这是我的主要活动

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    Intent intent = getIntent();
    String message = intent.getStringExtra("array_list");

    TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
    tabLayout.setTabTextColors(R.color.colorPrimaryDark, R.color.colorAccent);
    tabLayout.addTab(tabLayout.newTab().setText("Split").setIcon(R.drawable.money));
    tabLayout.addTab(tabLayout.newTab().setText("Item List").setIcon(R.drawable.list));
    tabLayout.addTab(tabLayout.newTab().setText("Rates").setIcon(R.drawable.settings));
    tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);


    final ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
    final PagerAdapter adapter = new PagerAdapter
            (getSupportFragmentManager(), tabLayout.getTabCount());
    viewPager.setAdapter(adapter);
    viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
    tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            viewPager.setCurrentItem(tab.getPosition());
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }

这是我的frag1

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View frag1v = inflater.inflate(R.layout.activity_frag1, container, false);

    //Add Button//
    Button b = (Button) frag1v.findViewById(R.id.add_btn);
    final ArrayList<Double> n = new ArrayList<Double>();
    final EditText e = (EditText) frag1v.findViewById(R.id.sum);
    final EditText d = (EditText) frag1v.findViewById(R.id.editText3);
    final TextView tx = (TextView) frag1v.findViewById(R.id.textView4);
    final Double div = Double.parseDouble(d.getText().toString());

    // Shared Setting //
    SharedPreferences Setting_pre = getActivity().getSharedPreferences("Setting", Context.MODE_PRIVATE);
    final String Discount_shared = Setting_pre.getString("Discount", "0");
    final String Service_shared = Setting_pre.getString("Service", "1.1");
    final String Tax_shared = Setting_pre.getString("Tax", "1.16");


    b.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (e.getText().length() > 0) {
                Double e_double = Double.parseDouble(e.getText().toString());
                Double div = Double.parseDouble(d.getText().toString());
                Double sum_d = e_double / div;
                n.add(sum_d);
            }
            Double sum = 0.0;
            for (int i = 0; i < n.size(); i++) {
                sum += n.get(i);
            }
            e.setText("");

            if (Discount_shared.equals("0")) {
                Double Discount_M = 1.0;
                Double sum_d = sum / div;
                Double Discount_Sum = sum_d * Discount_M;
                Double Service_M = Double.parseDouble(Service_shared.toString());
                Double Service_Sum = Discount_Sum * Service_M;
                Double Tax_M = Double.parseDouble(Tax_shared.toString());
                Double Tax_Sum = Service_Sum * Tax_M;
                String Total = Tax_Sum.toString().format("%.2f", Tax_Sum);
                tx.setText(Total);
            } else {
                Double Discount_M = Double.parseDouble(Discount_shared.toString());
                Double sum_d = sum / div;
                Double Discount_Sum = sum_d * Discount_M;
                Double Service_M = Double.parseDouble(Service_shared.toString());
                Double Service_Sum = Discount_Sum * Service_M;
                Double Tax_M = Double.parseDouble(Tax_shared.toString());
                Double Tax_Sum = Service_Sum * Tax_M;
                String Total = Tax_Sum.toString().format("%.2f", Tax_Sum);
                tx.setText(Total);
            }


        }
    });

    //clear//
    Button c = (Button) frag1v.findViewById(R.id.clear_btn);
    c.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            n.clear();
            tx.setText("0");
        }
    });


    return frag1v;

}

这是我的frag2

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View frag2v = inflater.inflate(R.layout.activity_frag2, container, false);



    return frag2v;
}

Answer 1

由于你的问题是你想知道如何使用意图发送它，这篇文章解决了这个问题：Pass ArrayList<Double> from one activity to another activity on android

代码示例：

FirstActivity：

Intent intent = new Intent(this, OtherActivity.class);
ArrayList<Double> listDouble = new ArrayList<Double>();
listDouble.add(1111.00000);
listDouble.add(13331.00000);
intent.putExtra("arraylist", listDouble);
startActivity(intent);

OtherActivity :(检索Double ArrayList）

ArrayList<Double> listDouble = (ArrayList<Double>) getIntent().getSerializableExtra("arraylist");
System.out.println("...serialized data.." + listDouble);

对于片段通讯，请查看以下帖子：Basic Communication between two fragments或官方文档：https://developer.android.com/training/basics/fragments/communicating.html

public class YourActivity implements FragmentA.TextClicked{
@Override
public void sendText(String text){
    // Get Fragment B
    FraB frag = (FragB)
        getSupportFragmentManager().findFragmentById(R.id.fragment_b);
    frag.updateText(text);
}

}

// Fragment A定义一个接口，并在需要时调用该方法公共类FragA扩展了Fragment {

TextClicked mCallback;

public interface TextClicked{
    public void sendText(String text);
}

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);

    // This makes sure that the container activity has implemented
    // the callback interface. If not, it throws an exception
    try {
        mCallback = (TextClicked) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString()
            + " must implement TextClicked");
    }
}

public void someMethod(){
    mCallback.sendText("YOUR TEXT");
}

@Override
public void onDetach() {
    mCallback = null; // => avoid leaking, thanks @Deepscorn
    super.onDetach();
}

}

//片段B有一个公共方法来处理文本公共类FragB扩展了Fragment {

public void updateText(String text){
    // Here you have it
}

}

在两个片段之间发送Arraylist

1 个答案: