Android Dev

如果你呼叫 startService() 多次，每一次的呼叫都會被轉成一個 message，並放在 mServiceLooper 的 message queue 中，等待被服務。一個 message 所對應的工作被完成後，才會繼續服務下一個工作。所以，這些等待被服務的工作，並不是一起並行 (Concurrent) 的，而是循序執行。

從研究這個 IntentService 的原始碼，我們可以學到如何運用簡單的 pattern (Service + Handler + HandlerThread)，幫我們更簡易與有系統地，完成我們所想要做的事

最後我們先前說過，在 IntentServcie 中等待被服務的工作，並不會被一起並行，而是循序執行。如果你今天想要這些等待被服務的工作，能夠一起被並行，在研讀完這個 IntentService 的原始碼後，你自己知不知道如何寫個可支援並行工作的 IntentService？ 提示：可以用 Service + AsyncTask 的組合

launches the pending intent

checkout flow finishes

to be normal

on a medium-density VGA screen

For completeness we really should handle the possibility of the task getting cancelled. This can happen when the user navigates away from the app and the task is killed before its completed. This will cause the onPostExecute() method to not be called and so the onRefreshComplete() method won’t be called. Depending on how the user navigates through the app, they could return to this activity without going through the complete onCreate() lifecycle, and you’ll end up with the screen still showing the “loading” progress message in the header. This is common when using tabs between multiple ListViews. Also, the documented best practices for implementing an AsyncTask says that in long running background work you should periodically check if the task has been cancelled and try to gracefully quit your work and exit. So let’s get all of that in there.

The action bar: is located at the top of the screen to support navigation and highlight important functionalities replaces the title bar (which is often included into it) is best used for actions across your app, like search, refresh and compose can provide a quick link to app homeby tapping the app logo is preferably not contextual, but actions can differ from page to page

Use when You want to bring key actions on screen, so they are in sight. You don't want to hide them under the menu-button. The action bar is best used for common actions like search, refresh and compose. When screen real estate is valuable, consider putting actions in the options menu.

So the basic idea is: launch an AsyncTask making your service call, show a nifty progress dialog while the task thread is running, and have the task’s result be posted back to your activity once it completes. Cool, but what if the user decides to rotate the screen while your task is running? Or a phone call comes in, interrupting your app, and Android decides to kill it? Both these actions will effectively terminateyour activity, and recreate it when resuming (yes, a screen rotation kills your activity, very clever, isn’t it?). Unfortunately, any AsyncTask that was still running now holds a stale reference to your activity, because the restarted activity will be an entirely different object in memory (and it will go through onCreate(), as if the activity had started for the first time). I’m not entirely sure whether AsyncTask will actually post back the data to the old activity object (if it was a weak reference, it may already have been garbage collected), but in any case, your “new” activity will never see it, because it’s a different instance.

Consumers want immediate access to what’s relevant and QR codes are being used to make that possible.

Bar codes are linear one-dimensional codes and can only hold up to 20 numerical digits, whereas QR codes are two-dimensional (2D) matrix barcodes that can hold thousands of alphanumeric characters of information. Their ability to hold more information and their ease of use makes them practical for small businesses.

When you scan or read a QR code with your iPhone, Android or other camera-enabled Smartphone, you can link to digital content on the web; activate a number of phone functions including email, IM and SMS; and connect the mobile device to a web browser.

I'm Johan, a Stockholm, Sweden based Web and Android developer that love APIs, hackathons and open source. Contact me using Twitter or email.

距离 iPad 2 发布会越来越近，各种传言也越来越多，包括 iPad 2 会更轻更薄、会在发布之日就开始发售等等。一起来看看之前的各种猜测，期待一下即将到来的发布活动吧

ifanr 将在 3 月 3 日凌晨两点在微博、Live 和推上为大家同步转播 iPad 2 发布会，敬请期待

Rhodes is an open source Ruby-based framework to rapidly build native apps for all major smartphone operating systems (iPhone, Windows Mobile, RIM, Symbian and Android). These are true native device applications (NOT mobile web apps) which work with synchronized local data and take advantage of device capabilities such as GPS, PIM contacts and calendar, camera, native mapping, push, barcode, signature capture, and Bluetooth.

FrameLayout is designed to block out an area on the screen to display a single item. You can add multiple children to a FrameLayout, but all children are pegged to the top left of the screen. Children are drawn in a stack, with the most recently added child on top. The size of the frame layout is the size of its largest child (plus padding), visible or not (if the FrameLayout's parent permits). Views that are GONE are used for sizing only if setConsiderGoneChildrenWhenMeasuring() is set to true.

三星在移动市场的进步令人瞩目，最近的旗舰 Galaxy S (I9000) 发售短短几周就已经达到了百万销量，三星期望该机型的总销量能够达到一千万部。考虑到这东西售价 600 美元，而且只在有限的国家有售，系统还不是最新，你应该知道乔教主为什么会在新闻发布会上提起韩国公司了吧

三星的机海战术在近几年获得了巨大的成功，WM，Android，自身的非智能机系统，Bada 几条腿走路，机型的定位明确，做工质量稳定，以此换来了市场份额的不断攀升，三星给其他厂商带来了很大的压力，不过对于我们消费者来说，竞争是越激烈越好啊

Then i've tried PendingIntent.FLAG_UPDATE_CURRENT i'm no longer crashing, but it always launches the activity with extras were put in the widget that was updated the last. It looks like pending intent is shared among my widget instances

I've changed the call to  PendingIntent pending = PendingIntent.getActivity(context, appWidgetId, intent, PendingIntent.FLAG_UPDATE_CURRENT); Now everything is cool except based on discussions i'm not sure how reliable it'll be . ( Doc says it's not supported yet )

PackageInfo pInfo = null; try {         pInfo = getPackageManager().getPackageInfo("com.beanie.test", PackageManager.GET_META_DATA);         } catch (NameNotFoundException e) {                 e.printStackTrace(); } System.out.println(pInfo.versionCode);