Java 无法从Android中的数据库填充listView中的数据

我正在开发一个android应用程序，我想在其中存储我的员工详细信息。我无法从数据库加载ListView中的数据

DatabaseHelper.java

\\import statement 
 public class DatabaseHelper extends SQLiteOpenHelper{

    public static final String EMPLOYEE_ID = "EmployeeId";
    public static final String EMPLOYEE_NAME = "Name";
    public static final String EMPLOYEE_USERNAME = "Username";
    public static final String EMPLOYEE_PASSWORD = "Password";
    public static final String EMPLOYEE_MANGER_ID = "ManagerId";

    public static final String CREATE_TABLE_EMPLOYEE = "CREATE TABLE "+TABLE_NAME_EMPLOYEE+" ("+EMPLOYEE_ID+" INTEGER PRIMARY KEY AUTOINCREMENT, "+EMPLOYEE_NAME+" varchar(30), "+EMPLOYEE_USERNAME+" varchar(8), "+EMPLOYEE_PASSWORD+" varchar(10), "+EMPLOYEE_MANGER_ID+" Int);";

    public static final String DROP_TABLE_EMPLOYEE = "DROP TABLE "+TABLE_NAME_EMPLOYEE+" IF EXISTS";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        this.context = context;         
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        try {
            db.execSQL(CREATE_TABLE_EMPLOYEE);
        } catch (SQLException e) {
            //toast message
        }
        //toast message
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

        try {
            db.execSQL(DROP_TABLE_EMPLOYEE);
            onCreate(db);
        } catch (SQLException e) {
            //toast message 
        }
        //toast message
    }   
}

\\import statement
public class EmployeeDatabaseHelper extends DatabaseHelper{

public EmployeeDatabaseHelper(Context context) {
    super(context); 
}

public Cursor getAllEmployee(){

    ArrayList<Employee> employeeArrayList = new ArrayList<Employee>();
    String sql = "select * from tblEmployee";
    SQLiteDatabase db = getWritableDatabase();
    Cursor cursor = db.rawQuery(sql, null);
    if (cursor.moveToFirst()) {
        do{
            Employee e  = new Employee();
            e.name = cursor.getString(cursor.getColumnIndex(EMPLOYEE_NAME));
            employeeArrayList.add(e);               
        } while (cursor.moveToNext());
    }       
    return cursor;  
}
}

public class EmployeeFragment extends Fragment {

EmployeeDatabaseHelper dbHelper;
ListView employeeList;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_employee, container, false);
    employeeList = (ListView) rootView.findViewById(R.id.employeeList);
    populateEmployeeList();
    return rootView;
}

public void populateEmployeeList(){

    Cursor cursor = dbHelper.getAllEmployee();
    String[] data = new String[] {dbHelper.EMPLOYEE_ID, dbHelper.EMPLOYEE_NAME};
    int[] id = new int[] {R.id.mainTextView, R.id.subTextView};
    SimpleCursorAdapter myAdapter = new SimpleCursorAdapter(getActivity(), R.layout.row, cursor, data, id);
    employeeList.setAdapter(myAdapter);

}
}

public class EmployeeDatabaseHelper {
DatabaseHelper dbhelper;

public EmployeeDatabaseHelper(Context applicationContext) {
    dbhelper= new DatabaseHelper(applicationContext);
}

public long insertEmployee(String name, String username, String password){
    SQLiteDatabase db = dbhelper.getWritableDatabase();
    ContentValues cv = new ContentValues();
    cv.put(EMPLOYEE_NAME,name);
    cv.put(EMPLOYEE_USERNAME,username);
    cv.put(EMPLOYEE_PASSWORD,password);
    long id = db.insert(TABLE_NAME_EMPLOYEE, null, cv);
    db.close();
    return id;      
}

public ArrayList<Employee> getAllEmployee(){

    ArrayList<Employee> employeeArrayList = new ArrayList<Employee>();
    SQLiteDatabase db = dbhelper.getWritableDatabase();
    Cursor cursor = db.query(TABLE_NAME_EMPLOYEE, null,null,null,null,null,null);

        while (cursor.moveToNext()) {
            Employee e  = new Employee();
            e.name = cursor.getString(cursor.getColumnIndex(EMPLOYEE_NAME));
            e.username = cursor.getString(cursor.getColumnIndex(EMPLOYEE_USERNAME));
            employeeArrayList.add(e);
        } 

    db.close();
    return employeeArrayList;
}
}

public class EmployeeFragment extends Fragment {

EmployeeDatabaseHelper dbHelper;
ListView employeeList;
public Cursor employees;
private ArrayList<Employee> arrlst;
private myadapter myadapter;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_employee, container, false);

    employeeList = (ListView) rootView.findViewById(R.id.employeeList);
    return rootView;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    populateEmployeeList();
}

public void populateEmployeeList(){

    dbHelper=new EmployeeDatabaseHelper(getActivity());
     arrlst = dbHelper.getAllEmployee();
    myadapter = new myadapter(getActivity());
    employeeList.setAdapter(myadapter);

}

class myadapter extends ArrayAdapter<Employee>{
Activity con;
private LayoutInflater Inflater;

public myadapter(Activity context) {
    super(context,R.layout.row);
    con=context;
     Inflater = (LayoutInflater)con.getSystemService(con.LAYOUT_INFLATER_SERVICE);
}

class ViewHolder{
    TextView tvid;
    TextView tvname;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    View vi = convertView;
     ViewHolder vh;
    if(vi==null){
        vh = new ViewHolder();
        vi= Inflater.inflate(R.layout.row, null);
        vh.tvid=(TextView)vi.findViewById(R.id.mainTextView);

        vh.tvname=(TextView)vi.findViewById(R.id.subTextView);
        vi.setTag(vh);

    }else{
        vh=(ViewHolder)vi.getTag();
    }
    Employee e =arrlst.get(position);
    vh.tvid.setText(e.name);
    vh.tvname.setText(e.username);
    return vi;
}
@Override
public int getCount() {
    // TODO Auto-generated method stub
    return arrlst.size();
}
}
}

我有另一个只处理employeetable的类，如插入、删除等，即从DatabaseHelper派生的EmployeeDatabaseHelper

EmployeeDatabaseHelper.java

\\import statement 
 public class DatabaseHelper extends SQLiteOpenHelper{

    public static final String EMPLOYEE_ID = "EmployeeId";
    public static final String EMPLOYEE_NAME = "Name";
    public static final String EMPLOYEE_USERNAME = "Username";
    public static final String EMPLOYEE_PASSWORD = "Password";
    public static final String EMPLOYEE_MANGER_ID = "ManagerId";

    public static final String CREATE_TABLE_EMPLOYEE = "CREATE TABLE "+TABLE_NAME_EMPLOYEE+" ("+EMPLOYEE_ID+" INTEGER PRIMARY KEY AUTOINCREMENT, "+EMPLOYEE_NAME+" varchar(30), "+EMPLOYEE_USERNAME+" varchar(8), "+EMPLOYEE_PASSWORD+" varchar(10), "+EMPLOYEE_MANGER_ID+" Int);";

    public static final String DROP_TABLE_EMPLOYEE = "DROP TABLE "+TABLE_NAME_EMPLOYEE+" IF EXISTS";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        this.context = context;         
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        try {
            db.execSQL(CREATE_TABLE_EMPLOYEE);
        } catch (SQLException e) {
            //toast message
        }
        //toast message
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

        try {
            db.execSQL(DROP_TABLE_EMPLOYEE);
            onCreate(db);
        } catch (SQLException e) {
            //toast message 
        }
        //toast message
    }   
}

\\import statement
public class EmployeeDatabaseHelper extends DatabaseHelper{

public EmployeeDatabaseHelper(Context context) {
    super(context); 
}

public Cursor getAllEmployee(){

    ArrayList<Employee> employeeArrayList = new ArrayList<Employee>();
    String sql = "select * from tblEmployee";
    SQLiteDatabase db = getWritableDatabase();
    Cursor cursor = db.rawQuery(sql, null);
    if (cursor.moveToFirst()) {
        do{
            Employee e  = new Employee();
            e.name = cursor.getString(cursor.getColumnIndex(EMPLOYEE_NAME));
            employeeArrayList.add(e);               
        } while (cursor.moveToNext());
    }       
    return cursor;  
}
}

public class EmployeeFragment extends Fragment {

EmployeeDatabaseHelper dbHelper;
ListView employeeList;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_employee, container, false);
    employeeList = (ListView) rootView.findViewById(R.id.employeeList);
    populateEmployeeList();
    return rootView;
}

public void populateEmployeeList(){

    Cursor cursor = dbHelper.getAllEmployee();
    String[] data = new String[] {dbHelper.EMPLOYEE_ID, dbHelper.EMPLOYEE_NAME};
    int[] id = new int[] {R.id.mainTextView, R.id.subTextView};
    SimpleCursorAdapter myAdapter = new SimpleCursorAdapter(getActivity(), R.layout.row, cursor, data, id);
    employeeList.setAdapter(myAdapter);

}
}

public class EmployeeDatabaseHelper {
DatabaseHelper dbhelper;

public EmployeeDatabaseHelper(Context applicationContext) {
    dbhelper= new DatabaseHelper(applicationContext);
}

public long insertEmployee(String name, String username, String password){
    SQLiteDatabase db = dbhelper.getWritableDatabase();
    ContentValues cv = new ContentValues();
    cv.put(EMPLOYEE_NAME,name);
    cv.put(EMPLOYEE_USERNAME,username);
    cv.put(EMPLOYEE_PASSWORD,password);
    long id = db.insert(TABLE_NAME_EMPLOYEE, null, cv);
    db.close();
    return id;      
}

public ArrayList<Employee> getAllEmployee(){

    ArrayList<Employee> employeeArrayList = new ArrayList<Employee>();
    SQLiteDatabase db = dbhelper.getWritableDatabase();
    Cursor cursor = db.query(TABLE_NAME_EMPLOYEE, null,null,null,null,null,null);

        while (cursor.moveToNext()) {
            Employee e  = new Employee();
            e.name = cursor.getString(cursor.getColumnIndex(EMPLOYEE_NAME));
            e.username = cursor.getString(cursor.getColumnIndex(EMPLOYEE_USERNAME));
            employeeArrayList.add(e);
        } 

    db.close();
    return employeeArrayList;
}
}

public class EmployeeFragment extends Fragment {

EmployeeDatabaseHelper dbHelper;
ListView employeeList;
public Cursor employees;
private ArrayList<Employee> arrlst;
private myadapter myadapter;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_employee, container, false);

    employeeList = (ListView) rootView.findViewById(R.id.employeeList);
    return rootView;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    populateEmployeeList();
}

public void populateEmployeeList(){

    dbHelper=new EmployeeDatabaseHelper(getActivity());
     arrlst = dbHelper.getAllEmployee();
    myadapter = new myadapter(getActivity());
    employeeList.setAdapter(myadapter);

}

class myadapter extends ArrayAdapter<Employee>{
Activity con;
private LayoutInflater Inflater;

public myadapter(Activity context) {
    super(context,R.layout.row);
    con=context;
     Inflater = (LayoutInflater)con.getSystemService(con.LAYOUT_INFLATER_SERVICE);
}

class ViewHolder{
    TextView tvid;
    TextView tvname;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    View vi = convertView;
     ViewHolder vh;
    if(vi==null){
        vh = new ViewHolder();
        vi= Inflater.inflate(R.layout.row, null);
        vh.tvid=(TextView)vi.findViewById(R.id.mainTextView);

        vh.tvname=(TextView)vi.findViewById(R.id.subTextView);
        vi.setTag(vh);

    }else{
        vh=(ViewHolder)vi.getTag();
    }
    Employee e =arrlst.get(position);
    vh.tvid.setText(e.name);
    vh.tvname.setText(e.username);
    return vi;
}
@Override
public int getCount() {
    // TODO Auto-generated method stub
    return arrlst.size();
}
}
}

java是我的另一个类

public class Employee {
 public String username;
 public String name;
 public String password;        
}

在row.xml中，我没有什么好东西，只有两个文本视图。（即mainTextView、subTextView） 在fragment_employee.xml中，我有一个按钮可以添加新员工。和一个列表以查看所有员工。我在这里结巴了。如果我对这个populateEmployeeList（）类进行注释，那么我的程序就可以运行了。否则它会意外关闭

日志目录

 FATAL EXCEPTION: main
  Process: com.threepin.deepakcorporation, PID: 9393
  java.lang.IllegalArgumentException: column '_id' does not exist
  at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:303)
  at android.widget.CursorAdapter.init(CursorAdapter.java:172)
  at android.widget.CursorAdapter.<init>(CursorAdapter.java:120)
  at android.widget.ResourceCursorAdapter.<init>(ResourceCursorAdapter.java:52)
  at android.widget.SimpleCursorAdapter.<init>(SimpleCursorAdapter.java:78)
  at com.threepin.deepakcorporation.EmployeeFragment.populateEmployeeList(EmployeeFragment.java:61)
  at com.threepin.deepakcorporation.EmployeeFragment.onActivityCreated(EmployeeFragment.java:52)
  at android.app.Fragment.performActivityCreated(Fragment.java:1708)
  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:908)
  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1062)
  at android.app.BackStackRecord.run(BackStackRecord.java:684)
  at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1447)
  at android.app.FragmentManagerImpl$1.run(FragmentManager.java:443)
  at android.os.Handler.handleCallback(Handler.java:733)
  at android.os.Handler.dispatchMessage(Handler.java:95)
  at android.os.Looper.loop(Looper.java:136)
  at android.app.ActivityThread.main(ActivityThread.java:5127)
  at java.lang.reflect.Method.invokeNative(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:515)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:825)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:641)
  at dalvik.system.NativeStart.main(Native Method)

致命异常：main
流程：com.threepin.deepakcorporation，PID:9393
java.lang.IllegalArgumentException:列“\u id”不存在
位于android.database.AbstractCursor.getColumnIndexOrThrow（AbstractCursor.java:303）
位于android.widget.CursorAdapter.init（CursorAdapter.java:172）
位于android.widget.CursorAdapter.（CursorAdapter.java:120）
位于android.widget.ResourceCursorAdapter。（ResourceCursorAdapter.java:52）
在android.widget.SimpleCursorAdapter。（SimpleCursorAdapter.java:78）
位于com.threepin.deepakcorporation.EmployeeFragment.populateEmployeeList（EmployeeFragment.java:61）
位于com.threepin.deepakcorporation.EmployeeFragment.onActivityCreated（EmployeeFragment.java:52）
位于android.app.Fragment.performActivityCreated（Fragment.java:1708）
在android.app.FragmentManagerImpl.moveToState（FragmentManager.java:908）
位于android.app.FragmentManagerImpl.moveToState（FragmentManager.java:1062）
运行（BackStackRecord.java:684）
位于android.app.FragmentManagerImpl.execPendingActions（FragmentManager.java:1447）
在android.app.FragmentManagerImpl$1.run（FragmentManager.java:443）
位于android.os.Handler.handleCallback（Handler.java:733）
位于android.os.Handler.dispatchMessage（Handler.java:95）
位于android.os.Looper.loop（Looper.java:136）
位于android.app.ActivityThread.main（ActivityThread.java:5127）
位于java.lang.reflect.Method.Invokenactive（本机方法）
位于java.lang.reflect.Method.invoke（Method.java:515）
在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run上（ZygoteInit.java:825）
位于com.android.internal.os.ZygoteInit.main（ZygoteInit.java:641）
在dalvik.system.NativeStart.main（本机方法）

如果我对这个populateEmployeeList（）类进行注释，那么我的程序就可以运行了。 否则它会意外关闭

因为从

EmployeeDatabaseHelper

类调用

getAllEmployee

方法时，

dbHelper

为

null

要解决此问题，请在使用

dbHelper

对象从类访问方法之前，通过在类构造函数中传递上下文来创建

EmployeeDatabaseHelper

类的对象：

 dbHelper=new EmployeeDatabaseHelper(getActivity());
 Cursor cursor = dbHelper.getAllEmployee();

如果我对这个populateEmployeeList（）类进行注释，那么我的程序就可以运行了。 否则它会意外关闭

因为从

EmployeeDatabaseHelper

类调用

getAllEmployee

方法时，

dbHelper

为

null

要解决此问题，请在使用

dbHelper

对象从类访问方法之前，通过在类构造函数中传递上下文来创建

EmployeeDatabaseHelper

类的对象：

 dbHelper=new EmployeeDatabaseHelper(getActivity());
 Cursor cursor = dbHelper.getAllEmployee();

---

尝试在片段的

onActivityCreated（）

方法中使用

populateEmployeeList（）

。

---

因为根据您的代码，您的视图尚未完成，您正试图通过调用

populateEmployeeList（）

来填充

listview

，

尝试使用
onActivityCreated（）
方法中的
populateEmployeeList（）
。
因为根据您的代码，您的视图尚未完成，并且您正试图通过调用
populateEmployeeList（）
列
\u id
来填充
列表视图
，请仔细阅读您的错误。您必须使用
\u id
字段：

@Override
public void onCreate(SQLiteDatabase paramSQLiteDatabase) {
    String sql="CREATE TABLE tableEQ (_ID INTEGER PRIMARY KEY," ...

}

列
\u id
不存在，请仔细阅读错误。您必须使用
\u id
字段：

@Override
public void onCreate(SQLiteDatabase paramSQLiteDatabase) {
    String sql="CREATE TABLE tableEQ (_ID INTEGER PRIMARY KEY," ...

}

我已经更改了代码。它正在运行。我不知道它是否会帮助别人，但仍然

DatabaseHelper.java中没有更改

EmployeeDatabaseHelper.java

\\import statement 
 public class DatabaseHelper extends SQLiteOpenHelper{

    public static final String EMPLOYEE_ID = "EmployeeId";
    public static final String EMPLOYEE_NAME = "Name";
    public static final String EMPLOYEE_USERNAME = "Username";
    public static final String EMPLOYEE_PASSWORD = "Password";
    public static final String EMPLOYEE_MANGER_ID = "ManagerId";

    public static final String CREATE_TABLE_EMPLOYEE = "CREATE TABLE "+TABLE_NAME_EMPLOYEE+" ("+EMPLOYEE_ID+" INTEGER PRIMARY KEY AUTOINCREMENT, "+EMPLOYEE_NAME+" varchar(30), "+EMPLOYEE_USERNAME+" varchar(8), "+EMPLOYEE_PASSWORD+" varchar(10), "+EMPLOYEE_MANGER_ID+" Int);";

    public static final String DROP_TABLE_EMPLOYEE = "DROP TABLE "+TABLE_NAME_EMPLOYEE+" IF EXISTS";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        this.context = context;         
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        try {
            db.execSQL(CREATE_TABLE_EMPLOYEE);
        } catch (SQLException e) {
            //toast message
        }
        //toast message
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

        try {
            db.execSQL(DROP_TABLE_EMPLOYEE);
            onCreate(db);
        } catch (SQLException e) {
            //toast message 
        }
        //toast message
    }   
}

\\import statement
public class EmployeeDatabaseHelper extends DatabaseHelper{

public EmployeeDatabaseHelper(Context context) {
    super(context); 
}

public Cursor getAllEmployee(){

    ArrayList<Employee> employeeArrayList = new ArrayList<Employee>();
    String sql = "select * from tblEmployee";
    SQLiteDatabase db = getWritableDatabase();
    Cursor cursor = db.rawQuery(sql, null);
    if (cursor.moveToFirst()) {
        do{
            Employee e  = new Employee();
            e.name = cursor.getString(cursor.getColumnIndex(EMPLOYEE_NAME));
            employeeArrayList.add(e);               
        } while (cursor.moveToNext());
    }       
    return cursor;  
}
}

public class EmployeeFragment extends Fragment {

EmployeeDatabaseHelper dbHelper;
ListView employeeList;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_employee, container, false);
    employeeList = (ListView) rootView.findViewById(R.id.employeeList);
    populateEmployeeList();
    return rootView;
}

public void populateEmployeeList(){

    Cursor cursor = dbHelper.getAllEmployee();
    String[] data = new String[] {dbHelper.EMPLOYEE_ID, dbHelper.EMPLOYEE_NAME};
    int[] id = new int[] {R.id.mainTextView, R.id.subTextView};
    SimpleCursorAdapter myAdapter = new SimpleCursorAdapter(getActivity(), R.layout.row, cursor, data, id);
    employeeList.setAdapter(myAdapter);

}
}

public class EmployeeDatabaseHelper {
DatabaseHelper dbhelper;

public EmployeeDatabaseHelper(Context applicationContext) {
    dbhelper= new DatabaseHelper(applicationContext);
}

public long insertEmployee(String name, String username, String password){
    SQLiteDatabase db = dbhelper.getWritableDatabase();
    ContentValues cv = new ContentValues();
    cv.put(EMPLOYEE_NAME,name);
    cv.put(EMPLOYEE_USERNAME,username);
    cv.put(EMPLOYEE_PASSWORD,password);
    long id = db.insert(TABLE_NAME_EMPLOYEE, null, cv);
    db.close();
    return id;      
}

public ArrayList<Employee> getAllEmployee(){

    ArrayList<Employee> employeeArrayList = new ArrayList<Employee>();
    SQLiteDatabase db = dbhelper.getWritableDatabase();
    Cursor cursor = db.query(TABLE_NAME_EMPLOYEE, null,null,null,null,null,null);

        while (cursor.moveToNext()) {
            Employee e  = new Employee();
            e.name = cursor.getString(cursor.getColumnIndex(EMPLOYEE_NAME));
            e.username = cursor.getString(cursor.getColumnIndex(EMPLOYEE_USERNAME));
            employeeArrayList.add(e);
        } 

    db.close();
    return employeeArrayList;
}
}

public class EmployeeFragment extends Fragment {

EmployeeDatabaseHelper dbHelper;
ListView employeeList;
public Cursor employees;
private ArrayList<Employee> arrlst;
private myadapter myadapter;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_employee, container, false);

    employeeList = (ListView) rootView.findViewById(R.id.employeeList);
    return rootView;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    populateEmployeeList();
}

public void populateEmployeeList(){

    dbHelper=new EmployeeDatabaseHelper(getActivity());
     arrlst = dbHelper.getAllEmployee();
    myadapter = new myadapter(getActivity());
    employeeList.setAdapter(myadapter);

}

class myadapter extends ArrayAdapter<Employee>{
Activity con;
private LayoutInflater Inflater;

public myadapter(Activity context) {
    super(context,R.layout.row);
    con=context;
     Inflater = (LayoutInflater)con.getSystemService(con.LAYOUT_INFLATER_SERVICE);
}

class ViewHolder{
    TextView tvid;
    TextView tvname;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    View vi = convertView;
     ViewHolder vh;
    if(vi==null){
        vh = new ViewHolder();
        vi= Inflater.inflate(R.layout.row, null);
        vh.tvid=(TextView)vi.findViewById(R.id.mainTextView);

        vh.tvname=(TextView)vi.findViewById(R.id.subTextView);
        vi.setTag(vh);

    }else{
        vh=(ViewHolder)vi.getTag();
    }
    Employee e =arrlst.get(position);
    vh.tvid.setText(e.name);
    vh.tvname.setText(e.username);
    return vi;
}
@Override
public int getCount() {
    // TODO Auto-generated method stub
    return arrlst.size();
}
}
}

公共类EmployeeDatabaseHelper{
数据库助手dbhelper；
公共EmployeeDatabaseHelper（上下文应用程序上下文）{
dbhelper=新的DatabaseHelper（applicationContext）；
}
public long insertEmployee（字符串名称、字符串用户名、字符串密码）{
SQLiteDatabase db=dbhelper.getWritableDatabase（）；
ContentValues cv=新的ContentValues（）；
简历（员工姓名、姓名）；
简历输入（员工用户名、用户名）；
简历输入（员工密码、密码）；
long id=db.insert（表\u NAME\u EMPLOYEE，null，cv）；
db.close（）；
返回id；
}
公共阵列列表getAllEmployee（）{
ArrayList employeeArrayList=新的ArrayList（）；
SQLiteDatabase db=dbhelper.getWritableDatabase（）；
Cursor Cursor=db.query（表\u NAME\u EMPLOYEE，null，null，null，null，null）；
while（cursor.moveToNext（））{
员工e=新员工（）；
e、 name=cursor.getString（cursor.getColumnIndex（EMPLOYEE_name））；
e、 username=cursor.getString（cursor.getColumnIndex（EMPLOYEE_username））；
新增（e）项；
} 
db.close（）；
返回员工列表；
}
}

EmployeeFragment.java

\\import statement 
 public class DatabaseHelper extends SQLiteOpenHelper{

    public static final String EMPLOYEE_ID = "EmployeeId";
    public static final String EMPLOYEE_NAME = "Name";
    public static final String EMPLOYEE_USERNAME = "Username";
    public static final String EMPLOYEE_PASSWORD = "Password";
    public static final String EMPLOYEE_MANGER_ID = "ManagerId";

    public static final String CREATE_TABLE_EMPLOYEE = "CREATE TABLE "+TABLE_NAME_EMPLOYEE+" ("+EMPLOYEE_ID+" INTEGER PRIMARY KEY AUTOINCREMENT, "+EMPLOYEE_NAME+" varchar(30), "+EMPLOYEE_USERNAME+" varchar(8), "+EMPLOYEE_PASSWORD+" varchar(10), "+EMPLOYEE_MANGER_ID+" Int);";

    public static final String DROP_TABLE_EMPLOYEE = "DROP TABLE "+TABLE_NAME_EMPLOYEE+" IF EXISTS";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        this.context = context;         
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        try {
            db.execSQL(CREATE_TABLE_EMPLOYEE);
        } catch (SQLException e) {
            //toast message
        }
        //toast message
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

        try {
            db.execSQL(DROP_TABLE_EMPLOYEE);
            onCreate(db);
        } catch (SQLException e) {
            //toast message 
        }
        //toast message
    }   
}

\\import statement
public class EmployeeDatabaseHelper extends DatabaseHelper{

public EmployeeDatabaseHelper(Context context) {
    super(context); 
}

public Cursor getAllEmployee(){

    ArrayList<Employee> employeeArrayList = new ArrayList<Employee>();
    String sql = "select * from tblEmployee";
    SQLiteDatabase db = getWritableDatabase();
    Cursor cursor = db.rawQuery(sql, null);
    if (cursor.moveToFirst()) {
        do{
            Employee e  = new Employee();
            e.name = cursor.getString(cursor.getColumnIndex(EMPLOYEE_NAME));
            employeeArrayList.add(e);               
        } while (cursor.moveToNext());
    }       
    return cursor;  
}
}

public class EmployeeFragment extends Fragment {

EmployeeDatabaseHelper dbHelper;
ListView employeeList;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_employee, container, false);
    employeeList = (ListView) rootView.findViewById(R.id.employeeList);
    populateEmployeeList();
    return rootView;
}

public void populateEmployeeList(){

    Cursor cursor = dbHelper.getAllEmployee();
    String[] data = new String[] {dbHelper.EMPLOYEE_ID, dbHelper.EMPLOYEE_NAME};
    int[] id = new int[] {R.id.mainTextView, R.id.subTextView};
    SimpleCursorAdapter myAdapter = new SimpleCursorAdapter(getActivity(), R.layout.row, cursor, data, id);
    employeeList.setAdapter(myAdapter);

}
}

public class EmployeeDatabaseHelper {
DatabaseHelper dbhelper;

public EmployeeDatabaseHelper(Context applicationContext) {
    dbhelper= new DatabaseHelper(applicationContext);
}

public long insertEmployee(String name, String username, String password){
    SQLiteDatabase db = dbhelper.getWritableDatabase();
    ContentValues cv = new ContentValues();
    cv.put(EMPLOYEE_NAME,name);
    cv.put(EMPLOYEE_USERNAME,username);
    cv.put(EMPLOYEE_PASSWORD,password);
    long id = db.insert(TABLE_NAME_EMPLOYEE, null, cv);
    db.close();
    return id;      
}

public ArrayList<Employee> getAllEmployee(){

    ArrayList<Employee> employeeArrayList = new ArrayList<Employee>();
    SQLiteDatabase db = dbhelper.getWritableDatabase();
    Cursor cursor = db.query(TABLE_NAME_EMPLOYEE, null,null,null,null,null,null);

        while (cursor.moveToNext()) {
            Employee e  = new Employee();
            e.name = cursor.getString(cursor.getColumnIndex(EMPLOYEE_NAME));
            e.username = cursor.getString(cursor.getColumnIndex(EMPLOYEE_USERNAME));
            employeeArrayList.add(e);
        } 

    db.close();
    return employeeArrayList;
}
}

public class EmployeeFragment extends Fragment {

EmployeeDatabaseHelper dbHelper;
ListView employeeList;
public Cursor employees;
private ArrayList<Employee> arrlst;
private myadapter myadapter;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_employee, container, false);

    employeeList = (ListView) rootView.findViewById(R.id.employeeList);
    return rootView;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    populateEmployeeList();
}

public void populateEmployeeList(){

    dbHelper=new EmployeeDatabaseHelper(getActivity());
     arrlst = dbHelper.getAllEmployee();
    myadapter = new myadapter(getActivity());
    employeeList.setAdapter(myadapter);

}

class myadapter extends ArrayAdapter<Employee>{
Activity con;
private LayoutInflater Inflater;

public myadapter(Activity context) {
    super(context,R.layout.row);
    con=context;
     Inflater = (LayoutInflater)con.getSystemService(con.LAYOUT_INFLATER_SERVICE);
}

class ViewHolder{
    TextView tvid;
    TextView tvname;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    View vi = convertView;
     ViewHolder vh;
    if(vi==null){
        vh = new ViewHolder();
        vi= Inflater.inflate(R.layout.row, null);
        vh.tvid=(TextView)vi.findViewById(R.id.mainTextView);

        vh.tvname=(TextView)vi.findViewById(R.id.subTextView);
        vi.setTag(vh);

    }else{
        vh=(ViewHolder)vi.getTag();
    }
    Employee e =arrlst.get(position);
    vh.tvid.setText(e.name);
    vh.tvname.setText(e.username);
    return vi;
}
@Override
public int getCount() {
    // TODO Auto-generated method stub
    return arrlst.size();
}
}
}

公共类EmployeeFragment扩展了片段{
EmployeeDatabaseHelper dbHelper；
ListView员工列表；
公职人员；
私人ArrayList arrlst；
私有myadapter myadapter；
@凌驾
创建视图上的公共视图（布局、充气机、视图组容器、，
Bundle savedInstanceState）{
视图根视图