第一次創建數據庫時的進度對話框

Question

我有一個應用程序可以創建一個SQLite數據庫（有24條記錄），我注意到當我第一次加載應用程序時，它需要一些實際加載主查看，我認爲這是因爲該應用程序是第一次創建數據庫。這是它在做什麼。 1）顯示開機畫面 2）黑屏 - 或以任何佈局不編程，這就是它的創建數據庫，我再次承擔 3）顯示主要佈局 - 目標

我喜歡找出在黑屏過程中顯示進度條的最好方法，如果可能的話，可以通過計算數據庫的插入數據，這裏不太確定。

這裏是我的代碼

SplashActivity.java

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(); 
     } 
    } 
} 
} 

Database.java

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"); 
} 
} 

MainActivity.java

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; 
    } 
} 
} 

不知道把這個最好的地方或者ho w才能正確實現，只有在創建數據庫時才顯示。任何想法或建議？

Answer 1

好吧，所以我決定改變整個過程，並最終用AsyncTask從我的網站下載文件並將它存儲在SD卡上。然後我只是打開數據庫，似乎都工作得更快，它顯示下載文件時的進度對話框。對於這裏感興趣的任何人是代碼：

注意：您必須在此之前創建您的數據庫。

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; 
    } 
} 
} 

然後你只想做訪問以下內容：

db = SQLiteDatabase.openDatabase(<file location on sd card>, null, SQLiteDatabase.OPEN_READWRITE); 

Answer 2

請測試：

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(); 

     } 

Answer 3

您需要用戶Handler & Runnable班這樣的操作。

請檢查我的回答here。