如何使用捆绑包一次从多个活动中获取数据

Question

我创建了一个应用程序，该应用程序从sql server的2个表中获取多个所选数据。 我使用了2个edittext来放置该数据； 我正在使用包从2个活动中获取数据，但是我没有获取数据。 我的代码是：

try{

     Bundle bn = getIntent().getExtras();

      ArrayList<String> data=  bn.getStringArrayList("selectedItems");
      ArrayList<String> data2=  bn.getStringArrayList("selectedItems2");
     //  String[] resultArr = b.getStringArray("selectedItems");
        StringBuilder string = new StringBuilder();
        for(int i=0;i<data.size();i++){
            string.append(data.get(i).toString()+"\n");
        }

        for(int i=0;i<data2.size();i++){
            string2.append(data2.get(i).toString()+"\n");
        }
        area.setText(string2);
        wwith.setText(string);
    } catch(Exception e){
            e.printStackTrace();
        }

谁能建议我如何使用捆绑软件从多个活动中获取数据？

主要活动的完整代码

public class DcrOpen extends Activity {
StringBuilder string=null;
StringBuilder string2=null;
EditText date,wwith,area;
Spinner with;
Button save,back,get,get1;
String paid5;
String dcrdate;
MyConnection mycon;
String mydate;







public void onCreate(Bundle b){
    super.onCreate(b);
    setContentView(R.layout.dcropen);

    date=(EditText)findViewById(R.id.date);
    wwith=(EditText)findViewById(R.id.workwith);
    area=(EditText)findViewById(R.id.area);

    with=(Spinner)findViewById(R.id.worktype);

    save=(Button)findViewById(R.id.save);
    back=(Button)findViewById(R.id.bkdays);
    get=(Button)findViewById(R.id.get);
    get1=(Button)findViewById(R.id.get1);


    mycon=new MyConnection(DcrOpen.this);
    int paid=MyConnection.PA_ID;

    try{

     Bundle bn = getIntent().getExtras();

      ArrayList<String> data=  bn.getStringArrayList("selectedItems");
      ArrayList<String> data2=  bn.getStringArrayList("selectedItems2");
     //  String[] resultArr = b.getStringArray("selectedItems");
        StringBuilder string = new StringBuilder();
        for(int i=0;i<data.size();i++){
            string.append(data.get(i).toString()+"\n");
        }

        for(int i=0;i<data2.size();i++){
            string2.append(data2.get(i).toString()+"\n");
        }
        area.setText(string2);
        wwith.setText(string);
    } catch(Exception e){
            e.printStackTrace();
        }















     ResultSet rs2;
try{

    Statement smt=mycon.connection().createStatement();
    rs2=smt.executeQuery("DCRDATEDDL "+paid+"");

     if(rs2.next()==false){

     }
        String mydate3=rs2.getString("DATE_NAME");

    date.setText(mydate3);
    rs2=smt.executeQuery("WORKINGTYPE");
    List<String>data1=new ArrayList<String>();
    while(rs2.next()){
        data1.add(rs2.getString("FIELD_NAME"));
    }
    ArrayAdapter<String>dataadapter=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,data1);
       dataadapter.setDropDownViewResource(android.R.layout.simple_list_item_single_choice);
       with.setAdapter(dataadapter);


}catch(Exception e){

}









    back.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent i=new Intent(getApplicationContext(),DcrMenu.class);
            startActivity(i);

        }
    });
    get.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent i=new Intent(getApplicationContext(),ListviewHelper.class);
            startActivity(i);

        }
    });

    get1.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent in=new Intent(getApplicationContext(),ListviewHelper2.class);
            startActivity(in);

        }
    });

}
}

活动ListviewHelper

public class ListviewHelper extends Activity implements OnClickListener {

                        Button button;
                        ListView listView;
                        ArrayAdapter<String> adapter;
                        MyConnection mycon;

                        /** Called when the activity is first created. */
                        @Override
                        public void onCreate(Bundle savedInstanceState) {
                        super.onCreate(savedInstanceState);
                        setContentView(R.layout.data_list);
                        mycon=new MyConnection(ListviewHelper.this);
                        int pa_id=mycon.PA_ID;
                        ResultSet rs;
                        List<String>data=new ArrayList<String>();
                        try{
                        Statement smt=mycon.connection().createStatement();
                        rs=smt.executeQuery("WORKWITH "+pa_id+",'','','','','','',''");

                        while(rs.next())
                        {
                            data.add(rs.getString("PA_NAME"));
                        }
                        }catch(Exception e){
                            e.printStackTrace();
                        }

                        findViewsById();


                        adapter = new ArrayAdapter<String>(this,
                                android.R.layout.simple_list_item_multiple_choice, data);
                        listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
                        listView.setAdapter(adapter);

                        button.setOnClickListener(this);
                        }

                        private void findViewsById() {
                        listView = (ListView) findViewById(R.id.list);
                        button = (Button) findViewById(R.id.testbutton);
                        }

                        public void onClick(View v) {
                        SparseBooleanArray checked = listView.getCheckedItemPositions();
                        ArrayList<String> selectedItems = new ArrayList<String>();
                        for (int i = 0; i < checked.size(); i++) {
                            // Item position in adapter
                            int position = checked.keyAt(i);
                            // Add sport if it is checked i.e.) == TRUE!
                            if (checked.valueAt(i))
                                selectedItems.add(adapter.getItem(position));
                        }

                        String[] outputStrArr = new String[selectedItems.size()];
                        List<String>data=new ArrayList<String>(selectedItems.size());
                        for (int i = 0; i < selectedItems.size(); i++) {
                           // outputStrArr[i] = selectedItems.get(i);
                        }

                        Intent intent = new Intent(getApplicationContext(),
                                DcrOpen.class);

                        // Create a bundle object
                        Bundle b = new Bundle();
                        b.putStringArrayList("selectedItems", selectedItems);

                        // Add the bundle to the intent.
                        intent.putExtras(b);

                        // start the ResultActivity
                        startActivity(intent);
                        }

}

活动ListviewHelper2

public class ListviewHelper2 extends Activity implements OnClickListener {

                        Button button;
                        ListView listView;
                        ArrayAdapter<String> adapter;
                        MyConnection mycon;

                        /** Called when the activity is first created. */
                        @Override
                        public void onCreate(Bundle savedInstanceState) {
                        super.onCreate(savedInstanceState);
                        setContentView(R.layout.data_list2);
                        mycon=new MyConnection(ListviewHelper2.this);
                        int pa_id=mycon.PA_ID;
                        ResultSet rs;
                        List<String>data=new ArrayList<String>();
                        try{
                        Statement smt=mycon.connection().createStatement();
                        rs=smt.executeQuery("DCRAREADDL "+pa_id+",'','','',''");

                        while(rs.next())
                        {
                            data.add(rs.getString("AREA"));
                        }
                        }catch(Exception e){
                            e.printStackTrace();
                        }

                        findViewsById();


                        adapter = new ArrayAdapter<String>(this,
                                android.R.layout.simple_list_item_multiple_choice, data);
                        listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
                        listView.setAdapter(adapter);

                        button.setOnClickListener(this);
                        }

                        private void findViewsById() {
                        listView = (ListView) findViewById(R.id.list2);
                        button = (Button) findViewById(R.id.testbutton2);
                        }

                        public void onClick(View v) {
                        SparseBooleanArray checked = listView.getCheckedItemPositions();
                        ArrayList<String> selectedItems = new ArrayList<String>();
                        for (int i = 0; i < checked.size(); i++) {
                            // Item position in adapter
                            int position = checked.keyAt(i);
                            // Add sport if it is checked i.e.) == TRUE!
                            if (checked.valueAt(i))
                                selectedItems.add(adapter.getItem(position));
                        }

                        String[] outputStrArr = new String[selectedItems.size()];
                        List<String>data=new ArrayList<String>(selectedItems.size());
                        for (int i = 0; i < selectedItems.size(); i++) {
                           // outputStrArr[i] = selectedItems.get(i);
                        }

                        Intent intent = new Intent(getApplicationContext(),
                                DcrOpen.class);

                        // Create a bundle object
                        Bundle b = new Bundle();
                        b.putStringArrayList("selectedItems2", selectedItems);

                        // Add the bundle to the intent.
                        intent.putExtras(b);

                        // start the ResultActivity
                        startActivity(intent);
                        }

}

Answer 1

填充导致您进入此活动的意图时，可以使用getIntent.getExtras() 。 例如：在活动1中：

Intent intent = new Intent(activity1.this, activity2.class);
intent.putExtra("test", test);
startActivity(intent);

然后，在第二个活动（活动2）中，您可以使用以下命令：

String test = getIntent().getExtras().get("test");

但是OnCreate（）中的onSaveInstanceState(Bundle)是在当前活动中通过使用onSaveInstanceState(Bundle)设置数据以保存数据时（例如在onStop（）调用时onSaveInstanceState(Bundle)使用的onSaveInstanceState(Bundle) 。