UIから重い処理をする場合のプログラミング比較(C#, Android Java, iOS Swift)

Android Java

public void onClick(View v) {
    new HeavyWorkTask().execute();
}
private class HeavyWorkTask extends AsyncTask<Void, Void, Void> {
    void onPreExecute() { doPreWorkInUIThread(); }
    /** The system calls this to perform work in a worker thread and
    * delivers it the parameters given to AsyncTask.execute() */
    protected void doInBackground() { doHeavyWork(); }
    /** The system calls this to perform work in the UI thread and delivers
    * the result from doInBackground() */
    void onPostExecute() { doPostWorkInUIThread(); }
}

iOS Swift

@IBAction func onClick(sender: AnyObject) {
    let qualityOfServiceClass = QOS_CLASS_BACKGROUND
    let backgroundQueue = dispatch_get_global_queue(qualityOfServiceClass, 0)
    doPreWorkInUIThread()
    dispatch_async(backgroundQueue, {
        doHeavyWork()
        dispatch_async(dispatch_get_main_queue(), 0), {
            doPostWorkInUIThread()
        })
    })
}

C#

public async void onClick(object sender, EventArgs e) {
    doPreWorkInUIThread();
    await Task.Run({ () => doHeavyWork(); });
    doPostWorkInUIThread();
}

まとめ

もっとも流れるように書けるのは、async/awaitパターンを有しているC#ちゃん！
Android JavaとかiOS Swiftはちょっち野暮ったいっすね＾w＾