Question

我的启动画面同步了我的应用：

当我使用时：

sd.execute("init_sync", null).get();

我的徽标（以xml定义）消失。如果我退出.get（），它就会出现。

这是我的代码：

 public class SplashScreen extends Activity {
private Context ctx = null;
private Usuario mUser = null;
SharedPreferences prefs;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.splash);
    ctx = this;
    prefs = PreferenceManager.getDefaultSharedPreferences(this);

    new Handler().post(new Runnable() {

        @Override
        public void run() {
            // Check if user exists
            Gson gson = new Gson();
            String jsonUser = prefs.getString("usuario", "");
            mUser = gson.fromJson(jsonUser, Usuario.class);

            if (NetworkUtils.isOnline(ctx)) {
                if (mUser != null) {
                    SyncData sd = new SyncData(ctx);
                    try {
                        sd.execute("init_sync", null).get();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    } catch (ExecutionException e) {
                        e.printStackTrace();
                    }

                } else {
                    Intent i = new Intent(SplashScreen.this, LoginActivity.class);
                    startActivity(i);
                }

            } else {
                if (mUser != null) {

                    Intent i = new Intent(SplashScreen.this, DashBoard.class);
                    startActivity(i);
                } else {
                    Toast.makeText(ctx, "Necesita Internet para loguearse", Toast.LENGTH_LONG).show();
                    finish();
                }
            }
        }
    });

}

}

我有几个asyncTask用于上传图片，并将MySQL数据库与我的SQLite数据库同步。所以，我需要等到所有进程结束才能知道是否有错误。

问题是我把它放在一个线程中，所以它不会影响UI。我哪里错了？

Answer 1

使用get()时，会导致UI线程等待。不要使用get()。您需要覆盖onPostExecute中的AsyncTask方法。

private Boolean task1Finished = false;
private Boolean task2Finished = false;
private Boolean task3Finished = false;

//...

SyncData sd1 = new SyncData(ctx) {
    @Override
    protected void onPostExecute(Object result) {
        task1Finished = true;
        goToNextActivity();
    }
};

SyncData sd2 = new SyncData(ctx) {
    @Override
    protected void onPostExecute(Object result) {
        task2Finished = true;
        goToNextActivity();
    }
};

SyncData sd3 = new SyncData(ctx) {
    @Override
    protected void onPostExecute(Object result) {
        task3Finished = true;
        goToNextActivity();
    }
};

try {
    sd1.execute();
    sd2.execute();
    sd3.execute();
} 
catch (InterruptedException e) {
    e.printStackTrace();
} 
catch (ExecutionException e) {
    e.printStackTrace();
}

//...

private void goToNextActivity() {
    if (task1Finished && task2Finished && task3Finished)
        // all tasks complete
}

Answer 2

就像@ashishduh所说，我在UI线程中。所以我改变了：

new Handler().post(new Runnable() {
@Override
        public void run() {
....
     }
}

通过

Runnable sync = new Runnable() {
        @Override
        public void run() {
 ....
     }
};

Thread t = new Thread(sync);
t.start();

它解决了我的问题！

启动画面不显示徽标：thread.execute.get（）

2 个答案: