Question

我有启动画面，可以在进入主要活动之前加载数据库sqlite。而我的问题，进度条布局运行后加载数据库。如果我们lauch app，app变成空白布局（加载数据库） - ＆gt;进度条运行 - ＆gt;主要活动。那么，如何在启动画面中使进度条和加载数据库一起运行？

IntroActivity.java：

public class IntroActivity extends Activity implements LoadingTaskFinishedListener {
private SQLiteDatabase db = null;
private DataKamus datakamus = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    datakamus = new DataKamus(this);
    db = datakamus.getWritableDatabase();
    datakamus.createTable(db);
    datakamus.generateData(db);

    setContentView(R.layout.activity_intro);

    ProgressBar progressBar = (ProgressBar) findViewById(R.id.progressbar_Horizontal);
     new Loading(progressBar, this).execute("");

}

@Override
public void onTaskFinished() {
    completeSplash();
}
private void completeSplash(){
    startApp();
    finish(); // Don't forget to finish this Splash Activity so the user can't return to it!
}
private void startApp() {
    Intent intent = new Intent(IntroActivity.this, MainActivity.class);
    startActivity(intent);
}

Loading.java：

public class Loading extends AsyncTask<String, Integer, Integer> {
public interface LoadingTaskFinishedListener {
    void onTaskFinished();
}

private final ProgressBar progressBar;
private final LoadingTaskFinishedListener finishedListener;

public Loading(ProgressBar progressBar,
        LoadingTaskFinishedListener finishedListener) {
    this.progressBar = progressBar;
    this.finishedListener = finishedListener;
}

@Override
protected Integer doInBackground(String... params) {
    Log.i("Tutorial", "Starting task with url: " + params[0]);
    if (resourcesDontAlreadyExist()) {
        downloadResources();
    }
    return 1234;

}

private boolean resourcesDontAlreadyExist() {

    return true;
}

private void downloadResources() {

    int count = 25;
    for (int i = 0; i < count; i++) {

        int progress = (int) ((i / (float) count) * 100);
        publishProgress(progress);

        try {
            Thread.sleep(100);
        } catch (InterruptedException ignore) {
        }
    }
}

@Override
protected void onProgressUpdate(Integer... values) {
    super.onProgressUpdate(values);
    progressBar.setProgress(values[0]);
}

@Override
protected void onPostExecute(Integer result) {
    super.onPostExecute(result);
    finishedListener.onTaskFinished();
}

Answer 1

您应该将所有数据库加载代码移动到asynctask。

Answer 2

您的简介活动，加载构造函数更改

public class IntroActivity extends Activity implements LoadingTaskFinishedListener {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_intro);

    ProgressBar progressBar = (ProgressBar) findViewById(R.id.progressbar_Horizontal);
     new Loading(progressBar, this, IntroActivity.this).execute("");

}

@Override
public void onTaskFinished() {
    completeSplash();
}
private void completeSplash(){
    startApp();
    finish(); // Don't forget to finish this Splash Activity so the user can't return to it!
}
private void startApp() {
    Intent intent = new Intent(IntroActivity.this, MainActivity.class);
    startActivity(intent);
}

}

你的异步类，

public class Loading extends AsyncTask<String, Integer, Integer> {
public interface LoadingTaskFinishedListener {
    void onTaskFinished();
}

private SQLiteDatabase db = null;
private DataKamus datakamus = null;

private final ProgressBar progressBar;
private final LoadingTaskFinishedListener finishedListener;

public Loading(ProgressBar progressBar,
        LoadingTaskFinishedListener finishedListener, Context context) {
    this.progressBar = progressBar;
    this.finishedListener = finishedListener;
    this.datakamus = new DataKamus(context);
}

@Override
protected Integer doInBackground(String... params) {
    /*
     * database
     */
    db = datakamus.getWritableDatabase();
    datakamus.createTable(db);
    datakamus.generateData(db);

    Log.i("Tutorial", "Starting task with url: " + params[0]);
    if (resourcesDontAlreadyExist()) {
        downloadResources();
    }
    return 1234;

}

private boolean resourcesDontAlreadyExist() {

    return true;
}

private void downloadResources() {

    int count = 25;
    for (int i = 0; i < count; i++) {

        int progress = (int) ((i / (float) count) * 100);
        publishProgress(progress);

        try {
            Thread.sleep(100);
        } catch (InterruptedException ignore) {
        }
    }
}

@Override
protected void onProgressUpdate(Integer... values) {
    super.onProgressUpdate(values);
    progressBar.setProgress(values[0]);
}

@Override
protected void onPostExecute(Integer result) {
    super.onPostExecute(result);
    finishedListener.onTaskFinished();
}
}

看，如果有效。

如何在启动画面中使进度条和加载数据库一起运行？

2 个答案: