Question

在我的应用程序中有一个SQLite数据库。我需要从表中的单独列（两列 - 名称和组织）中检索数据，我需要将这些值设置为单独的文本视图。这就是我的尝试。

这是我将表格数据添加到列表中的类。

DBAccess类

public class DBAccess {
private SQLiteOpenHelper openHelper;
private SQLiteDatabase database;
private static DBAccess instance;
String passedVar = null;
private ListView listView;

public DBAccess(Context context) {

    this.openHelper = new AppDB(context);
}

public static DBAccess getInstance(Context context) {
    if (instance == null) {
        instance = new DBAccess(context);
    }
    return instance;
}

public void open() {
    this.database = openHelper.getWritableDatabase();
}

public void close() {
    if (database != null) {
        this.database.close();
    }
}


public List<Contacts>getContacts(){
List<Contacts>list = new ArrayList<>();
    if (id != null) {
        Cursor cursor = database.rawQuery("SELECT * FROM Contacts WHERE mId = \"" + id + "\"", null);

    cursor.moveToFirst();
    while (!cursor.isAfterLast()) {

        Contacts con = new Contacts(cursor.getString(2),
                cursor.getString(cursor.getColumnIndex("name")));
        list.add(con);

        Contacts con1 = new Contacts(cursor.getString(4),cursor.getString(cursor.getColumnIndex("organization")));
        list.add(con1);

        cursor.moveToNext();
    }

    cursor.close();
}
return list;
}}

如何检索这些项目并在这些文本视图（tv1，tv2）上设置它们？

MainActivity类

public class MantraActivity extends MainActivity {
private ViewPager viewPager;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.mantra_view);


    DBAccess dba=  new DBAccess(MantraActivity.this);
    dba.open();


    TextView tv1= (TextView)findViewById(R.id.textView1);
    TextView tv2= (TextView)findViewById(R.id.textView2);

}}

联系人课程

public class Contacts {

public String mid;
public String name;
public String organization;


public Contacts(String mid, String name, String organization) {
    this.mid = mid;
    this.name = name;
    this.organization = organization;
}

public String getMid() {
    return mid;
}

public void setMid(String mid) {
    this.mid = mid;
}

public String getMantra() {
    return mantra;
}

public void setMantra(String mantra) {
    this.mantra = mantra;
}


   public String getOrganization() {
        return organization;
    }

public void setOrganization(String organization) {
    this.organization = organization;
}

}

Answer 1

首先，你要从数据库中为每一行添加两个联系人......不确定是否有意，但这是修复。

for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) {
    String mId = cursor.getString(2);
    String name = cursor.getString(cursor.getColumnIndex("name"));
    String organization = cursor.getString(cursor.getColumnIndex("organization"));

    Contacts con = new Contacts(mId, name, organization);
    list.add(con);
}

我需要将这些值设置为单独的文本视图。

为什么单独使用TextView？
您有一个ArrayList，因此使用ListView + ArrayAdapter将每个Contact加载到列表的一行中。

List<Contacts> contacts = db.getContacts();
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.id.simple_list_item_1);
for (Contact c : contacts) {
    adapter.add(c.getName() + " - " + c.getOrganization());
}
ListView listView = (ListView) findViewById(R.id.listView);
listView.setAdapter(adapter);

如何设置SQLite数据库的单独列值以分离文本视图？ - Android

1 个答案: