大家好，我现在已经开了6个月了。 iv一直在制作我的布局和编码等。 现在为上个月iv一直试图建立一个数据库。但我无法理解这个问题。我已经完成了android记事本教程，我已经下载了SQLite数据库浏览器。甚至我有一个来自记事本v3的工作数据库（添加和删除数据）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（现在找不到），有人把链接到我下载的数据库演示zip文件，当我运行它。它只是在追求什么。 希望你们可以帮助我，让我知道我是否可以将这个数据库演示作为我自己的...
不要误解我不是在寻找一个简单的方法来制作我自己的数据库或了解它。
在android世界中有很多东西需要学习。如果我有一个工作DB，我可以在其他项目上使用，我将学习编码的方式.. 这里是数据库演示的java代码，它有点沉重的粘贴所有这些对不起 如果您想查看我的XML，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);
}
}
答案 0 :(得分：0)
大多数Android演示，包括当前版本的Notepad，都使用Apache License v2.0。此许可证表明您可以自由使用和重新分发代码，但您必须保留所有现有通知和归属，并清楚地确认您已修改代码。 （准确的措辞见第4段。）