如何将数据从活动发送到 java 类

Posted 2023-02-26

【中文标题】如何将数据从活动发送到 java 类

【英文标题】：How to send data from an activity to a java class

【发布时间】：2017-03-03 04:59:24

【问题描述】：

如何通过微调器选择将 int 值从 locwebsActivity 发送到 DbBackend.java。我正在尝试将微调器的位置发送到该类，以便它从数据库中读取相关数据。

谢谢

public class locwebsActivity extends AppCompatActivity 

private ArrayAdapter<String> listAdapter;


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

    Spinner spinner = (Spinner) findViewById(R.id.spinner);

    final DbBackend dbBackend = new DbBackend(locwebsActivity.this);
    String[] spinnerLists = dbBackend.getAllSpinnerContent();

    ArrayAdapter<String> spinnerAdapter = new ArrayAdapter<String>(locwebsActivity.this,android.R.layout.simple_spinner_item, spinnerLists);
    spinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(spinnerAdapter);
    spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() 
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) 

            return;
        
        @Override
        public void onNothingSelected(AdapterView<?> parent) 

        
    );

java类：

public class DbBackend extends DbObject 

public DbBackend(Context context) 
    super(context);


public String[] getAllSpinnerContent()

    String query = "Select * from content";
    Cursor cursor = this.getDbConnection().rawQuery(query, null);
    ArrayList<String> spinnerContent = new ArrayList<String>();
    if(cursor.moveToFirst())
        do
            String word = cursor.getString(cursor.getColumnIndexOrThrow("content"));
            spinnerContent.add(word);
        while(cursor.moveToNext());
    
    cursor.close();

    String[] allSpinner = new String[spinnerContent.size()];
    allSpinner = spinnerContent.toArray(allSpinner);

    return allSpinner;

【参考方案1】：

你可以用这个：

@Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) 

            SharedPreferences sendnumber = getSharedPreferences("name", MODE_PRIVATE);
            SharedPreferences.Editor editor = sendnumber.edit();
            editor.putString("edtTextValue", pro);
            editor.commit();

            return;
        

在 DbBackend 中使用这个：

    Context c = Main212Activity.getContext();

    SharedPreferences sendnumber = c.getSharedPreferences("name", c.MODE_PRIVATE);
    String Uname = sendnumber.getString("edtTextValue", "");

    int Unameint = Integer.valueOf(Uname);

【讨论】：

@Damien Paul 我可以对这个答案发表你的看法吗？