变量在活动之间丢失数据，我不知道为什么？

Question

I am currently creating an android app that scans a network and outputs results in a ListView but I am trying to make it to where I tap on the network and it saves the data in a database then sends you to a page to show you what you selected but when I click an item it substrings the values correctly and displays work fine on the main activity but when I try to use the variables on my display page activity there values are set null.

Here is the main activity in the click listener:

networklist.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            String grabItemInfo = wifis[position];

            Network_Info info1 = new Network_Info();

            info1.setMainBSSID( grabItemInfo.substring(grabItemInfo.indexOf('#') +1, grabItemInfo.lastIndexOf('#')));
            info1.setMainSSID( grabItemInfo.substring(0,(grabItemInfo.indexOf('#'))));
            info1.setMainCAP( grabItemInfo.substring(grabItemInfo.lastIndexOf('#')+1, grabItemInfo.length()));


            Toast toastTest = Toast.makeText(getApplicationContext(), info1.getMainSSID(), Toast.LENGTH_SHORT);
            Toast toastTest2 = Toast.makeText(getApplicationContext(), info1.getMainBSSID(), Toast.LENGTH_SHORT);
            Toast toastTest3 = Toast.makeText(getApplicationContext(), info1.getMainCAP(), Toast.LENGTH_SHORT);
            toastTest.show();
            toastTest2.show();
            toastTest3.show();

            ContentValues dbv = new ContentValues();

            dbv.put("SSID", info1.getMainSSID());
            dbv.put("BSSID", info1.getMainBSSID());
            dbv.put("CAPABILITIES", info1.getMainCAP());




            netDataBase.insert("netDataTable", "NULL", dbv);


            Intent intent = new Intent(getApplicationContext(), Attack_Page.class);
            startActivity(intent);



        }
    });

Here is my display page:

public class Attack_Page extends Network_List {


protected void onCreate(Bundle SavedIS){

    super.onCreate(SavedIS);
    setContentView(R.layout.attack_page);


    TextView SSIDview = (TextView) findViewById(R.id.SSIDView);
    TextView BSSIDview = (TextView) findViewById(R.id.BSSIDView);
    TextView CAPview = (TextView) findViewById(R.id.CAPView);
    Button backButton = (Button) findViewById(R.id.backbutton);
    Intent intent = getIntent();

    //String MainSSIDP = intent.getStringExtra(getMainSSID());

    Network_Info info1 = new Network_Info();

    Toast testToast = Toast.makeText(getApplicationContext(),  info1.getMainSSID(), Toast.LENGTH_SHORT);
    testToast.show();

    //Cursor IDselect = netDataBase.rawQuery("SELECT SSID FROM netDataTable WHERE SSID = "+getMainSSID()+"", wifis);

    //SSIDview.setText(IDselect.toString());


    backButton.setOnClickListener(new View.OnClickListener(){

        public void onClick(View v){

            Intent bintent = new Intent(getApplicationContext(), Network_List.class);
            startActivity(bintent);

        }


    });

}

}

Here is my setters and getters class:

public class Network_Info {
   private String mainCAP;
   private String mainSSID;
   private String mainBSSID;

public void setMainSSID(String newMainSSID){

    mainSSID = newMainSSID;

}

public void setMainBSSID(String newMainBSSID){

    mainBSSID = newMainBSSID;

}

public void setMainCAP(String newMainCAP){

    mainCAP = newMainCAP;

}

public String getMainSSID(){

    return mainSSID;

}
public String getMainBSSID(){

    return mainBSSID;

}
public String getMainCAP(){

    return mainCAP;

}

}

Answer 1

Figured out you have to pass the variable with the intent:

Intent intent = new Intent(getApplicationContext(), Attack_Page.class);
            intent.putExtra("EXTRA_SSID", info1.getMainSSID());
            intent.putExtra("EXTRA_BSSID", info1.getMainBSSID());
            intent.putExtra("EXTRA_CAP", info1.getMainCAP());
            startActivity(intent);

Then use the key that you set in putExtra()

 String MainSSIDP = intent.getStringExtra("EXTRA_SSID");

Thanks for the help though!