java - 在 SQLiteOpenHelper onCreate 方法中显示 ProgressDialog

Question

我是 Android 编程新手。我正在编写一个简单的应用程序，应该在第一次运行时执行 sql 文件。但这个过程似乎需要几秒钟，所以我认为应用程序在执行 sql 文件时应该显示进度对话框。但是当我尝试运行应用程序时，对话框显示消息“应用程序已停止...”。请帮助我。

@Override
public void onCreate(SQLiteDatabase database)
{
    String CREATE_BIBLE_TABLE = "CREATE TABLE bible (" +
            "id INTEGER PRIMARY KEY AUTOINCREMENT, " +
            "book INTEGER, " +
            "chapter INTEGER NOT NULL, " +
            "verse INTEGER NOT NULL, " +
            "content TEXT" +
            ")";
    database.execSQL(CREATE_BIBLE_TABLE);

    new FirstLoadAsyncTask(database).execute();
}

public class FirstLoadAsyncTask extends AsyncTask<Void, Void, Void>
{
    private SQLiteDatabase database;
    private ProgressDialog progressDialog;

    public FirstLoadAsyncTask(SQLiteDatabase database)
    {
        this.database = database;
    }

    @Override
    protected void onPreExecute()
    {
        ((Activity) context).runOnUiThread(new Runnable()
        {
            @Override
            public void run()
            {
                progressDialog = ProgressDialog.show(context, "Loading...", "");
            }
        });
    }

    @Override
    protected Void doInBackground(Void... params)
    {
        try
        {
            InputStream inputStream = context.getAssets().open("bible.sql");
            execSqlFile(database, inputStream);
        } catch(IOException e)
        {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void result)
    {
        progressDialog.dismiss();
    }
} 

类扩展了 SQLiteOpenHelper。

编辑:日志猫:

01-06 18:27:53.221  14118-14118/pl.several27.Biblia_Warszawska E/Trace﹕ error opening trace file: No such file or directory (2)
01-06 18:27:53.891  14118-14118/pl.several27.Biblia_Warszawska I/Adreno200-EGL﹕ <qeglDrvAPI_eglInitialize:299>: EGL 1.4 QUALCOMM build: AU_LINUX_ANDROID_JB_REL_2.0.3.04.01.02.21.081_msm7627a_JB_REL_2.0.3_CL2820657_release_AU (CL2820657)
    Build Date: 01/22/13 Tue
    Local Branch:
    Remote Branch: quic/jb_rel_2.0.3
    Local Patches: NONE
    Reconstruct Branch: AU_LINUX_ANDROID_JB_REL_2.0.3.04.01.02.21.081 +  NOTHING
01-06 18:27:54.001  14118-14118/pl.several27.Biblia_Warszawska E/copybit﹕ Error opening frame buffer errno=13 (Permission denied)
01-06 18:27:54.001  14118-14118/pl.several27.Biblia_Warszawska W/Adreno200-EGLSUB﹕ <updater_create_surface_state:342>: updater_create_surface_state failed to open copybit, error: -13
01-06 18:27:54.011  14118-14118/pl.several27.Biblia_Warszawska D/memalloc﹕ ion: Mapped buffer base:0x53be8000 size:1536000 offset:0 fd:61
01-06 18:27:54.021  14118-14118/pl.several27.Biblia_Warszawska D/memalloc﹕ ion: Mapped buffer base:0x5083a000 size:4096 offset:0 fd:63
01-06 18:27:54.381  14118-14118/pl.several27.Biblia_Warszawska D/memalloc﹕ ion: Mapped buffer base:0x541fb000 size:1536000 offset:0 fd:66
01-06 18:27:54.381  14118-14118/pl.several27.Biblia_Warszawska D/memalloc﹕ ion: Mapped buffer base:0x50a50000 size:4096 offset:0 fd:68
01-06 18:27:54.501  14118-14118/pl.several27.Biblia_Warszawska D/memalloc﹕ ion: Mapped buffer base:0x54472000 size:1536000 offset:0 fd:70
01-06 18:27:54.501  14118-14118/pl.several27.Biblia_Warszawska D/memalloc﹕ ion: Mapped buffer base:0x50c75000 size:4096 offset:0 fd:72
01-06 18:27:55.001  14118-14118/pl.several27.Biblia_Warszawska D/memalloc﹕ ion: Mapped buffer base:0x545e9000 size:1536000 offset:0 fd:74
01-06 18:27:55.001  14118-14118/pl.several27.Biblia_Warszawska D/memalloc﹕ ion: Mapped buffer base:0x50d4c000 size:4096 offset:0 fd:76
01-06 18:27:57.231  14118-14118/pl.several27.Biblia_Warszawska D/book choosen﹕ 1
01-06 18:27:57.581  14118-14118/pl.several27.Biblia_Warszawska W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x40ca4540)
01-06 18:27:57.601  14118-14118/pl.several27.Biblia_Warszawska E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.RuntimeException: Unable to start activity ComponentInfo{pl.several27.Biblia_Warszawska/pl.several27.Biblia_Warszawska.ChapterActivity}: java.lang.ClassCastException: android.app.Application cannot be cast to android.app.Activity
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2355)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2391)
            at android.app.ActivityThread.access$600(ActivityThread.java:151)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1335)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:155)
            at android.app.ActivityThread.main(ActivityThread.java:5520)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1029)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:796)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.ClassCastException: android.app.Application cannot be cast to android.app.Activity
            at pl.several27.Biblia_Warszawska.Database$FirstLoadAsyncTask.onPreExecute(Database.java:58)
            at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
            at android.os.AsyncTask.execute(AsyncTask.java:534)
            at pl.several27.Biblia_Warszawska.Database.onCreate(Database.java:42)
            at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:252)
            at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:188)
            at pl.several27.Biblia_Warszawska.Database.countChapters(Database.java:148)
            at pl.several27.Biblia_Warszawska.ChapterActivity.onCreate(ChapterActivity.java:32)
            at android.app.Activity.performCreate(Activity.java:5066)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1101)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2311)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2391)
            at android.app.ActivityThread.access$600(ActivityThread.java:151)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1335)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:155)
            at android.app.ActivityThread.main(ActivityThread.java:5520)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1029)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:796)
            at dalvik.system.NativeStart.main(Native Method)
01-06 18:27:59.511  14118-14118/pl.several27.Biblia_Warszawska D/Process﹕ killProcess, pid=14118
01-06 18:27:59.521  14118-14118/pl.several27.Biblia_Warszawska D/Process﹕ dalvik.system.VMStack.getThreadStackTrace(Native Method)
01-06 18:27:59.521  14118-14118/pl.several27.Biblia_Warszawska D/Process﹕ java.lang.Thread.getStackTrace(Thread.java:599)
01-06 18:27:59.521  14118-14118/pl.several27.Biblia_Warszawska D/Process﹕ android.os.Process.killProcess(Process.java:956)
01-06 18:27:59.521  14118-14118/pl.several27.Biblia_Warszawska D/Process﹕ com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:108)
01-06 18:27:59.531  14118-14118/pl.several27.Biblia_Warszawska D/Process﹕ java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:693)
01-06 18:27:59.531  14118-14118/pl.several27.Biblia_Warszawska D/Process﹕ java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:690)
01-06 18:27:59.531  14118-14118/pl.several27.Biblia_Warszawska D/Process﹕ dalvik.system.NativeStart.main(Native Method)

我也尝试过这种方式display progressdialog in non-activity class但它也不会起作用。

这是整个应用程序源代码，但没有对话框:https://github.com/several27/BibliaWarszawska_Android

请问有人可以帮助我吗？

Answer 1

我在我的应用程序上执行了类似的操作，但我更喜欢在后台执行此操作，因此用户无法访问依赖于我的数据库的屏幕...

你可以尝试这样的事情:

public class BackgroundSyncService extends IntentService {

    public static final String NOTIFICATION = "com.example.sync.service";
public static final String RESULT = "result";

    public BackgroundSyncService() {
    super("BackgroundSyncService");
}

    @Override
protected void onHandleIntent(Intent intent) {
    //Do here what you want with your database

    //After all process you just notify your activitys
    Intent intent = new Intent(NOTIFICATION);
    intent.putExtra(RESULT, result);
sendBroadcast(intent);
    }

}

创建一个接收器(我在我的项目中使用内部类)

private BroadcastReceiver receiver = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            Bundle bundle = intent.getExtras();
            if (bundle != null) {
                    //Do what you want here , like enable a section of your app
            }
        }
    };

然后您需要将服务注册到您的 Activity 中，添加:

registerReceiver(receiver, new IntentFilter(BackgroundSyncService.NOTIFICATION));

不要忘记取消注册接收器:

@Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(receiver);
    }

另外，不要忘记在 AndroidManifest.xml 上注册您的 IntentService

<service android:name="com.example.service.BackgroundSyncService" />

编辑

您还需要包含在您想要的位置启动服务的调用，我在应用程序实例上启动我的服务:

Intent intent = new Intent(this, BackgroundSyncService.class);
startService(intent);

说明

首先，您正在创建一个服务来执行您想要的操作，该服务可以执行您想要的任何操作，在您的情况下，您将填充数据库...

创建此服务后，您将设置何时启动此服务(编辑部分)...

之后，您将注册您的 Activity 来监听服务，这就是我们创建 BroadcastReceiver 的原因，当您的服务执行以下行时将调用 BroadcastReceiver:

 //After all process you just notify your activitys
    Intent intent = new Intent(NOTIFICATION);
    intent.putExtra(RESULT, result);
    sendBroadcast(intent);