Java 第一次创建数据库时的进度对话框
我有一个创建SQLite数据库的应用程序（有24条记录），我注意到当我第一次加载应用程序时，实际加载主视图需要花费一些时间，我认为这是因为应用程序第一次创建数据库。这就是它所做的。 1.）显示启动屏幕 2.）空白屏幕-未在任何布局中编程，我想这也是创建数据库的地方 3.）显示主要布局-目标 我想找出在空白屏幕上显示进度条的最佳方法，如果可能的话，可能是通过计算数据库的插入，这里不确定。 这是我的密码 SplashActivity.javaJava 第一次创建数据库时的进度对话框,java,android,sqlite,progressdialog,Java,Android,Sqlite,Progressdialog,我有一个创建SQLite数据库的应用程序（有24条记录），我注意到当我第一次加载应用程序时，实际加载主视图需要花费一些时间，我认为这是因为应用程序第一次创建数据库。这就是它所做的。 1.）显示启动屏幕 2.）空白屏幕-未在任何布局中编程，我想这也是创建数据库的地方 3.）显示主要布局-目标 我想找出在空白屏幕上显示进度条的最佳方法，如果可能的话，可能是通过计算数据库的插入，这里不确定。 这是我的密码 SplashActivity.java package com.ondrovic.boomboz
package com.ondrovic.boombozzpassport;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
public class SplashActivity extends Activity{
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
SplashHandler sHandler = new SplashHandler();
setContentView(R.layout.splash);
Message msg = new Message();
msg.what = 0;
sHandler.sendMessageDelayed(msg, 3000);
}
private class SplashHandler extends Handler {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
default:
break;
case 0:
super.handleMessage(msg);
startActivity(new Intent(getApplicationContext(), MainActivity.class));
SplashActivity.this.finish();
}
}
}
}
package com.ondrovic.boombozzpassport;
import java.util.concurrent.atomic.AtomicBoolean;
import com.pushlink.android.PushLink;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.CursorAdapter;
import android.widget.ListView;
import android.widget.RatingBar;
import android.widget.TextView;
public class MainActivity extends Activity {
AtomicBoolean isActive = new AtomicBoolean(true);
BeerAdapter adapter = null;
Cursor model = null;
SQLiteDatabase db = null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
PushLink.start(this, R.drawable.ic_launcher, 10, "269f78b325ebda1c", true);
setContentView(R.layout.main);
db = (new Database(this)).getWritableDatabase();
ListView list = (ListView) findViewById(R.id.ListViewBeers);
model = Beer.getAll(db);
startManagingCursor(model);
adapter = new BeerAdapter(model);
list.setAdapter(adapter);
list.setOnItemClickListener(onListClick);
}
private AdapterView.OnItemClickListener onListClick = new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View v, int pos, long id) {
startActivity(new Intent(getApplicationContext(), BeerForm.class).putExtra(BeerForm.INTENT_BEER_ID, String.valueOf(id)));
}
};
@Override
public void onPause() {
super.onPause();
isActive.set(false);
}
@Override
public void onResume() {
super.onResume();
isActive.set(true);
}
@Override
public void onDestroy() {
super.onDestroy();
isActive.set(false);
db.close();
}
class BeerAdapter extends CursorAdapter {
public BeerAdapter(Cursor c) {
super(MainActivity.this, c);
}
@Override
public void bindView(View row, Context ctxt, Cursor c) {
BeerWrapper wrapper = (BeerWrapper)row.getTag();
wrapper.populateFrom(c);
}
@Override
public View newView(Context context, Cursor c, ViewGroup parent) {
LayoutInflater inflater = getLayoutInflater();
View row = inflater.inflate(R.layout.row, parent, false);
BeerWrapper wrapper = new BeerWrapper(row);
row.setTag(wrapper);
wrapper.populateFrom(c);
return row;
}
}
class BeerWrapper {
private TextView name = null;
private TextView brewer = null;
private TextView bdesc = null;
private RatingBar rating = null;
private View row = null;
BeerWrapper(View row) {
this.row = row;
}
void populateFrom(Cursor c) {
getName().setText(c.getString(c.getColumnIndex("name")));
getBrewer().setText(c.getString(c.getColumnIndex("brewer")));
getDesc().setText(c.getString(c.getColumnIndex("breifdescription")));
getRating().setRating(c.getFloat(c.getColumnIndex("rating")));
}
TextView getName() {
if (name == null) {
name = (TextView)row.findViewById(R.id.TextViewRowName);
}
return name;
}
TextView getBrewer() {
if (brewer == null) {
brewer = (TextView)row.findViewById(R.id.TextViewRowBrewer);
}
return brewer;
}
TextView getDesc() {
if (bdesc == null) {
bdesc = (TextView)row.findViewById(R.id.TextViewRowBriefDescription);
}
return bdesc;
}
RatingBar getRating() {
if (rating == null) {
rating = (RatingBar)row.findViewById(R.id.RatingBarRatingSmall);
}
return rating;
}
}
}
package com.ondrovic.boombozzpassport;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.provider.BaseColumns;
import android.util.Log;
public class Database extends SQLiteOpenHelper implements BaseColumns {
private final static String DB_NAME = "boombozz.db";
private final static int DB_VERSION = 1;
static final String TABLE_BEERS = "beers";
static final String COL_NAME = "name";
static final String COL_BREWER = "brewer";
static final String COL_ABV = "abv";
static final String COL_RATE = "rating";
static final String COL_BDESC = "breifdescription";
static final String COL_FDESC = "fulldescription";
static final String COL_TYPE = "type";
static final String COL_PIC = "picture";
private Context mContext;
public Database(Context context) {
super(context, DB_NAME, null, DB_VERSION);
mContext = context;
}
@Override
public void onCreate(SQLiteDatabase db) {
Log.w("onCreate : ","Creating Database Version: " + DB_VERSION);
db.execSQL("CREATE TABLE beers (" + "_id INTEGER PRIMARY KEY, "
+ "name TEXT, " + "brewer TEXT, " + "abv REAL, "
+ "rating REAL, " + "breifdescription TEXT, "
+ "fulldescription TEXT, " + "type TEXT, " + "picture BLOB);");
Log.w("onCreate","Inserting records into database");
addBeer(db, "NAME 1", "BREWER 1", "TYPE 1", "BDESC 1", "FDESC 1", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 2", "BREWER 2", "TYPE 2", "BDESC 2", "FDESC 2", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 3", "BREWER 3", "TYPE 3", "BDESC 3", "FDESC 3", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 4", "BREWER 4", "TYPE 4", "BDESC 4", "FDESC 4", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 5", "BREWER 5", "TYPE 5", "BDESC 5", "FDESC 5", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 6", "BREWER 6", "TYPE 6", "BDESC 6", "FDESC 6", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 7", "BREWER 7", "TYPE 7", "BDESC 7", "FDESC 7", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 8", "BREWER 8", "TYPE 8", "BDESC 8", "FDESC 8", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 9", "BREWER 9", "TYPE 9", "BDESC 9", "FDESC 9", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 10", "BREWER 10", "TYPE 10", "BDESC 10", "FDESC 10", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 11", "BREWER 11", "TYPE 11", "BDESC 11", "FDESC 11", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 12", "BREWER 12", "TYPE 12", "BDESC 12", "FDESC 12", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 13", "BREWER 13", "TYPE 13", "BDESC 13", "FDESC 13", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 14", "BREWER 14", "TYPE 14", "BDESC 14", "FDESC 14", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 15", "BREWER 15", "TYPE 15", "BDESC 15", "FDESC 15", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 16", "BREWER 16", "TYPE 16", "BDESC 16", "FDESC 16", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 17", "BREWER 17", "TYPE 17", "BDESC 17", "FDESC 17", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 18", "BREWER 18", "TYPE 18", "BDESC 18", "FDESC 18", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 19", "BREWER 19", "TYPE 19", "BDESC 19", "FDESC 19", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 20", "BREWER 20", "TYPE 20", "BDESC 20", "FDESC 20", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 21", "BREWER 21", "TYPE 21", "BDESC 21", "FDESC 21", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 22", "BREWER 22", "TYPE 22", "BDESC 22", "FDESC 22", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 23", "BREWER 23", "TYPE 23", "BDESC 23", "FDESC 23", 0, 0, R.drawable.beer1);
addBeer(db, "NAME 24", "BREWER 24", "TYPE 24", "BDESC 24", "FDESC 24", 0, 0, R.drawable.beer1);
}
private void addBeer(SQLiteDatabase db, String name, String brewer,
String type, String bdesc, String fdesc, int abv, int rate, int icon) {
final ContentValues cv = new ContentValues();
cv.put(COL_NAME, name);
cv.put(COL_BREWER, brewer);
cv.put(COL_TYPE, type);
cv.put(COL_BDESC, bdesc);
cv.put(COL_FDESC, fdesc);
cv.put(COL_ABV, abv);
cv.put(COL_RATE, rate);
final Bitmap bitmap = BitmapFactory.decodeResource(mContext.getResources(), icon);
writeBitmap(cv, COL_PIC, bitmap);
db.insert(TABLE_BEERS, null, cv);
}
static void writeBitmap(ContentValues cv, String name, Bitmap bitmap) {
if (bitmap != null) {
ByteArrayOutputStream out = new ByteArrayOutputStream();
try {
bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
out.flush();
out.close();
cv.put(name, out.toByteArray());
} catch (IOException e) {
// Ignore
}
}
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w("onUpgrade", "Upgrading database from version: " + oldVersion
+ " to version: " + newVersion);
db.execSQL("DROP TABLE IF EXISTS beers");
}
}
package com.ondrovic.boombozzpassport;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
public class SplashActivity extends Activity{
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
SplashHandler sHandler = new SplashHandler();
setContentView(R.layout.splash);
Message msg = new Message();
msg.what = 0;
sHandler.sendMessageDelayed(msg, 3000);
}
private class SplashHandler extends Handler {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
default:
break;
case 0:
super.handleMessage(msg);
startActivity(new Intent(getApplicationContext(), MainActivity.class));
SplashActivity.this.finish();
}
}
}
}
package com.ondrovic.boombozzpassport;
import java.util.concurrent.atomic.AtomicBoolean;
import com.pushlink.android.PushLink;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.CursorAdapter;
import android.widget.ListView;
import android.widget.RatingBar;
import android.widget.TextView;
public class MainActivity extends Activity {
AtomicBoolean isActive = new AtomicBoolean(true);
BeerAdapter adapter = null;
Cursor model = null;
SQLiteDatabase db = null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
PushLink.start(this, R.drawable.ic_launcher, 10, "269f78b325ebda1c", true);
setContentView(R.layout.main);
db = (new Database(this)).getWritableDatabase();
ListView list = (ListView) findViewById(R.id.ListViewBeers);
model = Beer.getAll(db);
startManagingCursor(model);
adapter = new BeerAdapter(model);
list.setAdapter(adapter);
list.setOnItemClickListener(onListClick);
}
private AdapterView.OnItemClickListener onListClick = new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View v, int pos, long id) {
startActivity(new Intent(getApplicationContext(), BeerForm.class).putExtra(BeerForm.INTENT_BEER_ID, String.valueOf(id)));
}
};
@Override
public void onPause() {
super.onPause();
isActive.set(false);
}
@Override
public void onResume() {
super.onResume();
isActive.set(true);
}
@Override
public void onDestroy() {
super.onDestroy();
isActive.set(false);
db.close();
}
class BeerAdapter extends CursorAdapter {
public BeerAdapter(Cursor c) {
super(MainActivity.this, c);
}
@Override
public void bindView(View row, Context ctxt, Cursor c) {
BeerWrapper wrapper = (BeerWrapper)row.getTag();
wrapper.populateFrom(c);
}
@Override
public View newView(Context context, Cursor c, ViewGroup parent) {
LayoutInflater inflater = getLayoutInflater();
View row = inflater.inflate(R.layout.row, parent, false);
BeerWrapper wrapper = new BeerWrapper(row);
row.setTag(wrapper);
wrapper.populateFrom(c);
return row;
}
}
class BeerWrapper {
private TextView name = null;
private TextView brewer = null;
private TextView bdesc = null;
private RatingBar rating = null;
private View row = null;
BeerWrapper(View row) {
this.row = row;
}
void populateFrom(Cursor c) {
getName().setText(c.getString(c.getColumnIndex("name")));
getBrewer().setText(c.getString(c.getColumnIndex("brewer")));
getDesc().setText(c.getString(c.getColumnIndex("breifdescription")));
getRating().setRating(c.getFloat(c.getColumnIndex("rating")));
}
TextView getName() {
if (name == null) {
name = (TextView)row.findViewById(R.id.TextViewRowName);
}
return name;
}
TextView getBrewer() {
if (brewer == null) {
brewer = (TextView)row.findViewById(R.id.TextViewRowBrewer);
}
return brewer;
}
TextView getDesc() {
if (bdesc == null) {
bdesc = (TextView)row.findViewById(R.id.TextViewRowBriefDescription);
}
return bdesc;
}
RatingBar getRating() {
if (rating == null) {
rating = (RatingBar)row.findViewById(R.id.RatingBarRatingSmall);
}
return rating;
}
}
}
package com.ondrovic.boombozzpassport；
导入java.util.concurrent.AtomicBoolean；
导入com.pushlink.android.pushlink；
导入android.app.Activity；
导入android.content.Context；
导入android.content.Intent；
导入android.database.Cursor；
导入android.database.sqlite.SQLiteDatabase；
导入android.os.Bundle；
导入android.view.LayoutInflater；
导入android.view.view；
导入android.view.ViewGroup；
导入android.widget.AdapterView；
导入android.widget.CursorAdapter；
导入android.widget.ListView；
导入android.widget.RatingBar；
导入android.widget.TextView；
公共类MainActivity扩展了活动{
AtomicBoolean isActive=新的AtomicBoolean（真）；
BeerAdapter适配器=null；
游标模型=空；
SQLiteDatabase db=null；
/**在首次创建活动时调用*/
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
PushLink.start（这是R.drawable.ic_发射器，10，“269f78b325ebda1c”，正确）；
setContentView（R.layout.main）；
db=（新数据库（this））.getWritableDatabase（）；
ListView列表=（ListView）findViewById（R.id.ListViewBeers）；
模型=Beer.getAll（db）；
开始管理光标（模型）；
适配器=新BeerAdapter（型号）；
list.setAdapter（适配器）；
list.setOnItemClickListener（onListClick）；
}
private AdapterView.OnItemClickListener onListClick=new AdapterView.OnItemClickListener（）{
@凌驾
public void onItemClick（AdapterView父视图、视图v、整数位置、长id）{
startActivity（新的Intent（getApplicationContext（），BeerForm.class）.putExtra（BeerForm.Intent\u BEER\u ID，String.valueOf（ID））；
}
};
@凌驾
公共无效暂停（）{
super.onPause（）；
isActive.set（false）；
}
@凌驾
恢复时公开作废（）{
super.onResume（）；
isActive.set（真）；
}
@凌驾
公共空间{
super.ondestory（）；
isActive.set（false）；
db.close（）；
}
类BeerAdapter扩展游标适配器{
公共蜂王器（光标c）{
super（MainActivity.this，c）；
}
@凌驾
public void bindView（视图行、上下文ctxt、光标c）{
啤酒包装器=（啤酒包装器）行。getTag（）；
包装器。从（c）开始普及；
}
@凌驾
公共视图newView（上下文上下文、光标c、视图组父对象）{
LayoutInflater充气机=getLayoutInflater（）；
视图行=充气机。充气（R.layout.row，父级，false）；
啤酒瓶包装=新啤酒瓶（世界其他地区）；
row.setTag（包装器）；
包装器。从（c）开始普及；
返回行；
}
}
啤酒瓶{
私有文本视图名称=null；
私有TextView brewer=null；
私有文本视图bdesc=null；
私人评级条评级=空；
私有视图行=null；
啤酒桶（视图行）{
this.row=行；
}
无效populateFrom（光标c）{
getName（）.setText（c.getString（c.getColumnIndex（“name”））；
getBrewer（）.setText（c.getString（c.getColumnIndex（“brewer”））；
getDesc（）.setText（c.getString（c.getColumnIndex（“breifdescription”））；
getRating（）.setRating（c.getFloat（c.getColumnIndex（“rating”）））；
}
TextView getName（）{
if（name==null）{
name=（TextView）row.findViewById（R.id.TextViewRowName）；
}
返回名称；
}
text视图getBrewer（）{
if（brewer==null）{
brewer=（TextView）row.findViewById（R.id.TextViewRowBrewer）；
}
返酒机；
}
TextView getDesc（）{
如果（bdesc==null）{
bdesc=（TextView）row.findViewById（R.id.textViewRowDescription）；
}
返回bdesc；
}
RatingBar getRating（）{
如果（额定值==null）{
评级=（评级条）行。findViewById（R.id.RatingBarRatingSmall）；
}
回报率；
}
}
}
ProgressDialog bar;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
loading();
bar.dismiss();
}
private void loading() {
bar = ProgressDialog.show(this, "Please wait",
"Long operation starts...", true);
new Thread((new Runnable() {
@Override
public void run() {
bar.setMessage("Loading...");
db = (new Database(this)).getWritableDatabase();
ListView list = (ListView) findViewById(R.id.ListViewBeers);
model = Beer.getAll(db);
startManagingCursor(model);
adapter = new BeerAdapter(model);
list.setAdapter(adapter);
list.setOnItemClickListener(onListClick);
}
})).start();
}
您需要使用
处理程序可运行请检查我的答案。好的，所以我决定改变整个过程，最后执行一个异步任务，从我的站点下载文件并将其存储在SD卡上。然后我刚刚打开数据库，一切似乎都运行得更快，下载文件时显示进度对话框。对于任何感兴趣的人，请参见以下代码： 注意：在此之前，您必须已经创建了数据库 Downloader.java
package com.ondrovic.downloader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.Intent;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
public class Downloader extends Activity {
SQLiteDatabase db = null;
public static final String LOG_TAG = "DOWNLOADER";
private ProgressDialog bar;
public static final int PROGRESS = 0;
File rDIR = Environment.getExternalStorageDirectory();
public String fDIR = "<location you want to store file on SD card>";
public String fNAME = "<your database.db>";
public String fURL = "<your url>";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
checkDB();
//DIRExists(fDIR);
//new Download().execute(fURL);
}
class Download extends AsyncTask <String, String, String> {
@Override
public void onPreExecute() {
super.onPreExecute();
showDialog(PROGRESS);
}
@Override
protected String doInBackground(String... aurl) {
try {
URL url = new URL(fURL);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("GET");
con.setDoOutput(true);
con.connect();
int fSIZE = con.getContentLength();
FileOutputStream out = new FileOutputStream(new File(rDIR + fDIR, fNAME));
InputStream in = con.getInputStream();
byte[] buffer = new byte[1024];
int len = 0;
long total = 0;
while ((len = in.read(buffer)) > 0) {
total += len;
publishProgress("" + (int)((total*100)/fSIZE));
out.write(buffer, 0, len);
}
out.close();
} catch (Exception e) {
Log.d(LOG_TAG, e.getMessage());
}
return null;
}
protected void onProgressUpdate(String... progress) {
Log.d(LOG_TAG, progress[0]);
bar.setProgress(Integer.parseInt(progress[0]));
}
@Override
protected void onPostExecute(String unused) {
dismissDialog(PROGRESS);
startActivity(new Intent(getApplicationContext(), Main.class));
Downloader.this.finish();
}
}
public void DIRExists(String dirName) {
File nDIR = new File(rDIR + dirName);
if (!nDIR.exists()) {
nDIR.mkdirs();
}
}
private boolean checkDB() {
try {
db = SQLiteDatabase.openDatabase(rDIR + fDIR + fNAME, null,
SQLiteDatabase.OPEN_READONLY);
db.close();
startActivity(new Intent(getApplicationContext(), Main.class));
Downloader.this.finish();
} catch (SQLException sqle) {
Log.d(LOG_TAG, sqle.getMessage());
DIRExists(fDIR);
new Download().execute(fURL);
}
return db != null;
}
@Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case PROGRESS:
bar = new ProgressDialog(this);
bar.setTitle("Database");
bar.setMessage("Downloading database...");
bar.setIndeterminate(false);
bar.setMax(100);
bar.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
bar.setCancelable(false);
bar.show();
return bar;
default:
return null;
}
}
}
package com.ondrovic.downloader；
导入java.io.File；
导入java.io.FileOutputStream；
导入java.io.InputStream；
导入java.net.HttpURLConnection；
导入java.net.URL；
导入android.app.Activity；
导入android.app.Dialog；
导入android.app.ProgressDialog；
导入android.content.Intent；
导入android.database.SQLException；
导入android.database.sqlite.SQLiteDatabase；
导入android.os.AsyncTask；
导入android.os.Bundle；
导入android.os.Environment；
导入android.util.Log；
公共类下载程序扩展活动{
SQLiteDatabase db=null；
公共静态最终字符串日志\u TAG=“DOWNLOADER”；
专用对话框栏；