-1

大家好,我已经制作我的应用程序 6 个月了。我一直在研究我的布局和编码等。现在上个月我一直在尝试创建一个数据库。但我就是无法解决这个问题。我已经完成了 android 记事本教程,并且我已经下载了 SQLite 数据库浏览器。即使我有一个来自notepad v3(添加和删除数据)的工作数据库,我只是不知道我是否可以在我的项目中使用这个数据库演示。

我也在一些堆栈溢出页面上(现在找不到它),有人放了一个指向我下载并运行它的数据库演示 zip 文件的链接。它正是我所追求的。希望你们能帮助我,让我知道我是否可以将这个数据库演示用作我自己的..

不要误会我的意思,我不是在寻找一种简单的方法来制作我自己的数据库或学习它。

在安卓世界里有很多东西要学。如果我有一个可以在其他项目中使用的工作数据库,我将一路学习编码。这是数据库演示的 java 代码,如果您想查看我的 XML,粘贴所有这些内容有点重请说..

     package mina.android.DatabaseDemo;
      import android.app.Activity;
      import android.app.Dialog;
      import android.database.Cursor;
      import android.os.Bundle;
      import android.text.Spannable;
      import android.view.View;
      import android.widget.AdapterView;
      import android.widget.EditText;
      import android.widget.SimpleCursorAdapter;
       import android.widget.Spinner;
      import android.widget.TextView;
      import android.widget.AdapterView.OnItemSelectedListener;

       public class AddEmployee extends Activity {
       EditText txtName;
       EditText txtAge;
       TextView txtEmps;
       DatabaseHelper dbHelper;
        Spinner spinDept;

       @Override
         public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.addemployee);
         txtName=(EditText)findViewById(R.id.txtName);
         txtAge=(EditText)findViewById(R.id.txtAge);
         txtEmps=(TextView)findViewById(R.id.txtEmps);
         spinDept=(Spinner)findViewById(R.id.spinDept);
        }

    @Override
    public void onStart()
   {
    try
    {
    super.onStart();
    dbHelper=new DatabaseHelper(this);



        txtEmps.setText(txtEmps.getText()+String.valueOf(dbHelper.getEmployeeCount()));

    Cursor c=dbHelper.getAllDepts();
    startManagingCursor(c);



    //SimpleCursorAdapter ca=new  

       SimpleCursorAdapter(this,android.R.layout.simple_spinner_item, c, new String [] 

       {DatabaseHelper.colDeptName}, new int []{android.R.id.text1});
    SimpleCursorAdapter ca=new   

         SimpleCursorAdapter(this,R.layout.deptspinnerrow, c, new String []


        {DatabaseHelper.colDeptName,"_id"}, new int []{R.id.txtDeptName});



        //ca.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    spinDept.setAdapter(ca);
    spinDept.setOnItemSelectedListener(new OnItemSelectedListener() {

        public void onItemSelected(AdapterView<?> parent, View   
                    selectedView,
                int position, long id) {
            // TODO Auto-generated method stub

        }

        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub

        }
    });


    //never close cursor
    }
    catch(Exception ex)
    {
        CatchError(ex.toString());
    }
    }

     public void btnAddEmp_Click(View view)
   {
    boolean ok=true;
    try
    {
        Spannable spn=txtAge.getText();
        String name=txtName.getText().toString();
        int age=Integer.valueOf(spn.toString());
        int deptID=Integer.valueOf((int)spinDept.getSelectedItemId());
        Employee emp=new Employee(name,age,deptID);

        dbHelper.AddEmployee(emp);

    }
    catch(Exception ex)
    {
        ok=false;
        CatchError(ex.toString());
    }
    finally
    {
        if(ok)
        {
            //NotifyEmpAdded();
            Alerts.ShowEmpAddedAlert(this);
            txtEmps.setText("Number of employees 

                        "+String.valueOf(dbHelper.getEmployeeCount()));
        }
      }
     }

      void CatchError(String Exception)
   {
    Dialog diag=new Dialog(this);
    diag.setTitle("Add new Employee");
    TextView txt=new TextView(this);
    txt.setText(Exception);
    diag.setContentView(txt);
    diag.show();
     }

     void NotifyEmpAdded()
    {
    Dialog diag=new Dialog(this);
    diag.setTitle("Add new Employee");
    TextView txt=new TextView(this);
    txt.setText("Employee Added Successfully");
    diag.setContentView(txt);
    diag.show();
    try {
        diag.wait(1000);
    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        CatchError(e.toString());
    }
    diag.notify();
    diag.dismiss();
     }

       }

   package mina.android.DatabaseDemo;


    import android.app.AlertDialog;
    import android.app.Dialog;
    import android.content.Context;
    import android.content.DialogInterface;
    import android.content.DialogInterface.OnClickListener;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.widget.Spinner;
    import android.widget.TextView;

    public class Alerts {
    public static void ShowEmpAddedAlert(Context con)
     {
     AlertDialog.Builder builder=new AlertDialog.Builder(con);
     builder.setTitle("Add new Employee");
     builder.setIcon(android.R.drawable.ic_dialog_info);
     DialogListner listner=new DialogListner();
     builder.setMessage("Employee Added successfully");
     builder.setPositiveButton("ok", listner);

    AlertDialog diag=builder.create();
    diag.show();
        }




    public static AlertDialog ShowEditDialog(final Context con,final Employee emp)
    {
   AlertDialog.Builder b=new AlertDialog.Builder(con);
   b.setTitle("Employee Details");
   LayoutInflater li=LayoutInflater.from(con);
   View v=li.inflate(R.layout.editdialog, null);

   b.setIcon(android.R.drawable.ic_input_get);

   b.setView(v);
   final TextView txtName=(TextView)v.findViewById(R.id.txtDelName);
   final TextView txtAge=(TextView)v.findViewById(R.id.txtDelAge);
   final Spinner spin=(Spinner)v.findViewById(R.id.spinDiagDept);
   Utilities.ManageDeptSpinner(con, spin);
   for(int i=0;i<spin.getCount();i++)
   {
    long id=spin.getItemIdAtPosition(i);
    if(id==emp.getDept())
    {
        spin.setSelection(i, true);
        break;
        }
       }


   txtName.setText(emp.getName());
    txtAge.setText(String.valueOf(emp.getAge()));

   b.setPositiveButton("Modify", new OnClickListener() {

    public void onClick(DialogInterface dialog, int which) {
        // TODO Auto-generated method stub
        emp.setName(txtName.getText().toString());
        emp.setAge(Integer.valueOf(txtAge.getText().toString()));


        emp.setDept((int)spin.getItemIdAtPosition(spin.getSelectedItemPosition()));



        try
        {
        DatabaseHelper db=new DatabaseHelper(con);
        db.UpdateEmp(emp);

        }
        catch(Exception ex)
        {
            CatchError(con, ex.toString());
        }
       }
      });

      b.setNeutralButton("Delete", new OnClickListener() {

    public void onClick(DialogInterface dialog, int which) {
        // TODO Auto-generated method stub
        DatabaseHelper db=new DatabaseHelper(con);
        db.DeleteEmp(emp);
       }
    });
     b.setNegativeButton("Cancel", null);

      return b.create();
      //diag.show();

          }

         static public void CatchError(Context con, String Exception)
        {
     Dialog diag=new Dialog(con);
     diag.setTitle("Error");
     TextView txt=new TextView(con);
     txt.setText(Exception);
     diag.setContentView(txt);
     diag.show();
          }
            }


        package mina.android.DatabaseDemo

        import android.app.TabActivity;
        import android.content.Intent;
         import android.os.Bundle;
        import android.view.Menu;
        import android.view.MenuItem;
        import android.widget.GridView;
        import android.widget.TabHost;
        import android.widget.TextView;

        public class DatabaseDemo extends TabActivity {
    DatabaseHelper dbHelper;
    GridView grid;
    TextView txtTest;
        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        SetupTabs();

       }





         @Override
       public boolean onCreateOptionsMenu(Menu menu)
        {
        menu.add(1, 1, 1, "Add Employee");
       return true;
       }







        public boolean onOptionsItemSelected(MenuItem item)
       {
       switch (item.getItemId())
       {
        //Add employee
       case 1:
        Intent addIntent=new Intent(this,AddEmployee.class);
        startActivity(addIntent);
        break;
       }
       super.onOptionsItemSelected(item);
      return false;
       }

      void SetupTabs()
      {

       TabHost host=getTabHost();

       TabHost.TabSpec spec=host.newTabSpec("tag1");
       Intent in1=new Intent(this, AddEmployee.class);
       spec.setIndicator("Add Employee");
       spec.setContent(in1);

       TabHost.TabSpec spec2=host.newTabSpec("tag2");
       Intent in2=new Intent(this, GridList.class);

       spec2.setIndicator("Employees");
       spec2.setContent(in2);
       host.addTab(spec);
       host.addTab(spec2);
        }
       }

       package mina.android.DatabaseDemo;

       import android.content.ContentValues;
       import android.content.Context;
       import android.database.Cursor;
       import android.database.sqlite.SQLiteDatabase;
       import android.database.sqlite.SQLiteOpenHelper;

      public class DatabaseHelper extends SQLiteOpenHelper {

    static final String dbName="demoDB";
    static final String employeeTable="Employees";
    static final String colID="EmployeeID";
    static final String colName="EmployeeName";
    static final String colAge="Age";
     static final String colDept="Dept";

    static final String deptTable="Dept";
    static final String colDeptID="DeptID";
    static final String colDeptName="DeptName";

     static final String viewEmps="ViewEmps";


     public DatabaseHelper(Context context) {
    super(context, dbName, null,33);

    // TODO Auto-generated constructor stub
    }

   @Override
    public void onCreate(SQLiteDatabase db) {
    // TODO Auto-generated method stub

    db.execSQL("CREATE TABLE "+deptTable+" ("+colDeptID+ " INTEGER PRIMARY KEY 
          , "+
            colDeptName+ " TEXT)");

    db.execSQL("CREATE TABLE "+employeeTable+" ("+colID+" INTEGER PRIMARY KEY 
          AUTOINCREMENT, "+
            colName+" TEXT, "+colAge+" Integer, "+colDept+" INTEGER 

        NOT NULL ,FOREIGN KEY ("+colDept+") REFERENCES "+deptTable+"  
        ("+colDeptID+"));");


    db.execSQL("CREATE TRIGGER fk_empdept_deptid " +
            " BEFORE INSERT "+
            " ON "+employeeTable+

            " FOR EACH ROW BEGIN"+
            " SELECT CASE WHEN ((SELECT "+colDeptID+" FROM 

            "+deptTable+" WHERE "+colDeptID+"=new."+colDept+" ) IS NULL)"+
            " THEN RAISE (ABORT,'Foreign Key Violation') END;"+
            "  END;");

    db.execSQL("CREATE VIEW "+viewEmps+
            " AS SELECT "+employeeTable+"."+colID+" AS _id,"+
            " "+employeeTable+"."+colName+","+
            " "+employeeTable+"."+colAge+","+
            " "+deptTable+"."+colDeptName+""+
            " FROM "+employeeTable+" JOIN "+deptTable+
            " ON "+employeeTable+"."+colDept+" 

        ="+deptTable+"."+colDeptID
            );
    //Inserts pre-defined departments
    InsertDepts(db);

     }

    @Override
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // TODO Auto-generated method stub

    db.execSQL("DROP TABLE IF EXISTS "+employeeTable);
    db.execSQL("DROP TABLE IF EXISTS "+deptTable);

    db.execSQL("DROP TRIGGER IF EXISTS dept_id_trigger");
    db.execSQL("DROP TRIGGER IF EXISTS dept_id_trigger22");
    db.execSQL("DROP TRIGGER IF EXISTS fk_empdept_deptid");
    db.execSQL("DROP VIEW IF EXISTS "+viewEmps);
    onCreate(db);
    }

    void AddEmployee(Employee emp)
    {


     SQLiteDatabase db= this.getWritableDatabase();


    ContentValues cv=new ContentValues();

    cv.put(colName, emp.getName());
    cv.put(colAge, emp.getAge());
    cv.put(colDept, emp.getDept());
    //cv.put(colDept,2);

    db.insert(employeeTable, colName, cv);
    db.close();


   }

    int getEmployeeCount()
   {
    SQLiteDatabase db=this.getWritableDatabase();
    Cursor cur= db.rawQuery("Select * from "+employeeTable, null);
    int x= cur.getCount();
    cur.close();
    return x;
    }

    Cursor getAllEmployees()
    {
     SQLiteDatabase db=this.getWritableDatabase();



     //Cursor cur= db.rawQuery("Select "+colID+" as _id , "+colName+", 

        "+colAge+" from "+employeeTable, new String [] {});
     Cursor cur= db.rawQuery("SELECT * FROM "+viewEmps,null);
     return cur;

   }

   Cursor getAllDepts()
   {
     SQLiteDatabase db=this.getReadableDatabase();
     Cursor cur=db.rawQuery("SELECT "+colDeptID+" as _id, "+colDeptName+" from 

        "+deptTable,new String [] {});

     return cur;
   }

      void InsertDepts(SQLiteDatabase db)
     {
     ContentValues cv=new ContentValues();
        cv.put(colDeptID, 1);
        cv.put(colDeptName, "Sales");
        db.insert(deptTable, colDeptID, cv);
        cv.put(colDeptID, 2);
        cv.put(colDeptName, "IT");
        db.insert(deptTable, colDeptID, cv);
        cv.put(colDeptID, 3);
        cv.put(colDeptName, "HR");
        db.insert(deptTable, colDeptID, cv);
        db.insert(deptTable, colDeptID, cv);

        }

         public String GetDept(int ID)
     {
     SQLiteDatabase db=this.getReadableDatabase();

     String[] params=new String[]{String.valueOf(ID)};
     Cursor c=db.rawQuery("SELECT "+colDeptName+" FROM"+ deptTable+" WHERE 

        "+colDeptID+"=?",params);
     c.moveToFirst();
     int index= c.getColumnIndex(colDeptName);
     return c.getString(index);
    }

    public Cursor getEmpByDept(String Dept)
    {
     SQLiteDatabase db=this.getReadableDatabase();
     String [] columns=new String[]{"_id",colName,colAge,colDeptName};
     Cursor c=db.query(viewEmps, columns, colDeptName+"=?", new String[] 

         {Dept}, null, null, null);
     return c;
    }

    public int GetDeptID(String Dept)
    {
     SQLiteDatabase db=this.getReadableDatabase();
     Cursor c=db.query(deptTable, new String[]{colDeptID+" as 

            _id",colDeptName},colDeptName+"=?", new String[]{Dept}, null, null, null);
     //Cursor c=db.rawQuery("SELECT "+colDeptID+" as _id FROM "+deptTable+" 

            WHERE "+colDeptName+"=?", new String []{Dept});
     c.moveToFirst();
     return c.getInt(c.getColumnIndex("_id"));

     }

     public int UpdateEmp(Employee emp)
     {
     SQLiteDatabase db=this.getWritableDatabase();
     ContentValues cv=new ContentValues();
     cv.put(colName, emp.getName());
     cv.put(colAge, emp.getAge());
     cv.put(colDept, emp.getDept());
     return db.update(employeeTable, cv, colID+"=?", new String  

          []{String.valueOf(emp.getID())});

    }

     public void DeleteEmp(Employee emp)
   {
     SQLiteDatabase db=this.getWritableDatabase();
     db.delete(employeeTable,colID+"=?", new String []    

            {String.valueOf(emp.getID())});
     db.close();
            }
             }

       package mina.android.DatabaseDemo;

      import android.content.DialogInterface;

      public class DialogListner implements  
      android.content.DialogInterface.OnClickListener {


public DialogListner()
{

}

public void onClick(DialogInterface dialog, int which) {
    // TODO Auto-generated method stub

}

    }


       package mina.android.DatabaseDemo;

     import android.content.Context;

     public class Employee {

int _id;
String _name;
int _age;
int _dept;

public Employee(String Name,int Age,int Dept)
{

    this._name=Name;
    this._age=Age;
    this._dept=Dept;
}

public Employee(String Name,int Age)
{
    this._name=Name;
    this._age=Age;
}

public int getID()
{
    return this._id;
}
public void SetID(int ID)
{
    this._id=ID;
}

public String getName()
{
    return this._name;
}

public int getAge()
{
    return this._age;
}

public void setName(String Name)
{
    this._name=Name;
}
public void setAge(int Age)
{
    this._age=Age;
}



public void setDept(int Dept)
{
    this._dept=Dept;
}

public String getDeptName(Context con, int Dept)
{
    return new DatabaseHelper(con).GetDept(Dept);
}
public int getDept()
{
    return this._dept;
}
     }


      package mina.android.DatabaseDemo;

      import android.app.Activity;
     import android.app.AlertDialog;
     import android.content.DialogInterface;
     import android.content.DialogInterface.OnDismissListener;
     import android.database.Cursor;
     import android.database.sqlite.SQLiteCursor;
     import android.os.Bundle;
     import android.view.View;
     import android.widget.AdapterView;
     import android.widget.GridView;
     import android.widget.SimpleCursorAdapter;
     import android.widget.Spinner;
     import android.widget.TextView;
     import android.widget.AdapterView.OnItemClickListener;
    import android.widget.AdapterView.OnItemSelectedListener;

    public class GridList extends Activity {
DatabaseHelper dbHelper;
static public GridView grid;
TextView txtTest;
Spinner spinDept1;
/** Called when the activity is first created. */
     @Override
     public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.gridview);
    grid=(GridView)findViewById(R.id.grid);
    txtTest=(TextView)findViewById(R.id.txtTest);
    spinDept1=(Spinner)findViewById(R.id.spinDept1);

    Utilities.ManageDeptSpinner(this.getParent(),spinDept1);
    final DatabaseHelper db=new DatabaseHelper(this);
    try
    {

http://img856.imageshack.us/img856/446/hoop.png

     spinDept1.setOnItemSelectedListener(new OnItemSelectedListener() {

        public void onItemSelected(AdapterView<?> arg0, View arg1,
                int arg2, long arg3) {
            // TODO Auto-generated method stub
            LoadGrid();
            //sca.notifyDataSetChanged();

        }

        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub

        }
    });

        }
        catch(Exception ex)
        {
        txtTest.setText(ex.toString());
        }



        try
       {
         grid.setOnItemClickListener(new OnItemClickListener()
        {

        public void onItemClick(AdapterView<?> parent, View v, int position,
                long id) {
            // TODO Auto-generated method stub
            try
            {

            SQLiteCursor 
            cr=(SQLiteCursor)parent.getItemAtPosition(position);
            String 
             name=cr.getString(cr.getColumnIndex(DatabaseHelper.colName));
            int  
               age=cr.getInt(cr.getColumnIndex(DatabaseHelper.colAge));
            String 
               Dept=cr.getString(cr.getColumnIndex(DatabaseHelper.colDeptName));
            Employee emp=new Employee(name, age,db.GetDeptID(Dept));
            emp.SetID((int)id);
            AlertDialog diag= Alerts.ShowEditDialog(GridList.this,emp);
            diag.setOnDismissListener(new OnDismissListener() {

                public void onDismiss(DialogInterface dialog) {
                    // TODO Auto-generated method stub
                    txtTest.setText("dismissed");

            //((SimpleCursorAdapter)grid.getAdapter()).notifyDataSetChanged();
                    LoadGrid();
                }
            });
            diag.show();
            }
            catch(Exception ex)
            {
                Alerts.CatchError(GridList.this, ex.toString());
            }
        }


       }
        );
        }
        catch(Exception ex)
        {

        }

         }

           @Override
           public void onStart()
        {
        super.onStart();
         //LoadGrid();
          }

           public void LoadGrid()
          {
         dbHelper=new DatabaseHelper(this);
        try
         {
        //Cursor c=dbHelper.getAllEmployees();
        View v=spinDept1.getSelectedView();
        TextView txt=(TextView)v.findViewById(R.id.txtDeptName);
        String Dept=String.valueOf(txt.getText());
        Cursor c=dbHelper.getEmpByDept(Dept);
        startManagingCursor(c);

        String [] from=new String 
          []{DatabaseHelper.colName,DatabaseHelper.colAge,DatabaseHelper.colDeptName};
        int [] to=new int [] {R.id.colName,R.id.colAge,R.id.colDept};
        SimpleCursorAdapter sca=new  
          SimpleCursorAdapter(this,R.layout.gridrow,c,from,to);
        grid.setAdapter(sca);



        }
         catch(Exception ex)
        {
        AlertDialog.Builder b=new AlertDialog.Builder(this);
        b.setMessage(ex.toString());
        b.show();
       }
          }

          }

       package mina.android.DatabaseDemo;


        import android.content.Context;
        import android.database.Cursor;
        import android.widget.SimpleCursorAdapter;
        import android.widget.Spinner;

       public class Utilities {
       static public void ManageDeptSpinner(Context context,Spinner view)
       {
    DatabaseHelper dbHelper=new DatabaseHelper(context);
    Cursor c=dbHelper.getAllDepts();
    //context.startManagingCursor(c);



   //SimpleCursorAdapter ca=new 
       SimpleCursorAdapter(this,android.R.layout.simple_spinner_item, c, new String [] 
       {DatabaseHelper.colDeptName}, new int []{android.R.id.text1});
   SimpleCursorAdapter ca=new   
     SimpleCursorAdapter(context,R.layout.deptspinnerrow,c, 
       new String [] {DatabaseHelper.colDeptName,"_id"}, new int []{R.id.txtDeptName});
    view.setAdapter(ca);

        }
        }
4

1 回答 1

0

大多数 Android 演示,包括当前版本的记事本,都使用Apache License v2.0。该许可证规定您可以自由使用和重新分发代码,但您必须保留所有现有的通知和归属,并明确承认您已经修改了代码。(具体措辞见第 4 段。)

于 2012-06-18T18:11:55.193 回答