Android Dev

对于苹果为何要起诉HTC专利侵权有很多猜测，其中一个猜测是苹果对使用Android系统的手机数量上升而感到了威胁。根据最新的移动Web使用统计，苹果的担忧不无道理。 大型移动广告公司AdMob，跟踪了点击他们广告的移动手机型号和操作系统。数据显示，iPhone使用率停滞不前，已经呈现下降颓势；Windows Mobile仍然是微不足道；而webOS和RIM看来也不是令人乐观——注意这些数据是用户使用智能手机上网的比率，并非是实际销售数量。在2009年11月，iPhone OS占到美国移动Web使用的55%，而现在则下降到了44%，在此期间，Android从27%增加到了42%。也就是说目前iPhone OS和Android不分伯仲，差距极小。 根据Statcounter的统计，过去一周中国搜索引擎市场，百度和Google的起伏也十分大。Google最高一天达到了49.52%；百度最低为48.72%，最高59.51%。

As part of my job, I ran into memory leaks issues in Android applications and they are most of the time due to the same mistake: keeping a long-lived reference to a Context.

There are two easy ways to avoid context-related memory leaks. The most obvious one is to avoid escaping the context outside of its own scope. The example above showed the case of a static reference but inner classes and their implicit reference to the outer class can be equally dangerous. The second solution is to use the Application context. This context will live as long as your application is alive and does not depend on the activities life cycle. If you plan on keeping long-lived objects that need a context, remember the application object. You can obtain it easily by calling Context.getApplicationContext() or Activity.getApplication().

In summary, to avoid context-related memory leaks, remember the following: Do not keep long-lived references to a context-activity (a reference to an activity should have the same life cycle as the activity itself) Try using the context-application instead of a context-activity Avoid non-static inner classes in an activity if you don't control their life cycle, use a static inner class and make a weak reference to the activity inside. The solution to this issue is to use a static inner class with a WeakReference to the outer class, as done in ViewRoot and its W inner class for instance A garbage collector is not an insurance against memory leaks

Removing the window's background can be achieved very easily by using a custom theme. To do so, first create a file called res/values/theme.xml containing the following:

<resources>    <style name="Theme.NoBackground" parent="android:Theme">        <item name="android:windowBackground">@null</item>    </style></resources>

You then need to apply the theme to your activity by adding the attribute android:theme="@style/Theme.NoBackground" to your <activity /> or <application /> tag. This trick comes in very handy for any app that uses a MapView, a WebView or any other full screen opaque view.

On an HTC Hero, this EXTRA_OUTPUT doesn't even work. It doesn't put your picture in the file you specify, but it hands it to you thru a Mediastore uri. Apparently, the only way to get a full size picture is to do all camera handling in your app instead of using the IMAGE_CAPTURE intent.

I think Google have missed a trick on this one. They have defined standard intents for media capture, but not specified standard responses (ie. the "data" parameter in the onActivityResult Activity callback method). Other Android vendors (e.g. HTC Hero) have created their own Camera applications that handle the standard IMAGE_CAPTURE intent, but return different data & have different ways to save/return the image information. All I want is to be able to fire a IMAGE_CAPTURE intent from my own app, and get back a Uri reference to the captured image. Simple. I have no requirement to further manipulate the image .. I just need the Uri to store in my app's database for future reference.

In my_button we define 4 states (as a button has 4 states: not pressed and not focused, pressed and focused, pressed and not focused, not pressed and focused) with each of those states having their own drawable.

Spinner s2 = (Spinner) findViewById(R.id.spinner2);Cursor cur = managedQuery(People.CONTENT_URI, PROJECTION, null, null);     SimpleCursorAdapter adapter2 = new SimpleCursorAdapter(this,    android.R.layout.simple_spinner_item, // Use a template                                          // that displays a                                          // text view    cur, // Give the cursor to the list adatper    new String[] {People.NAME}, // Map the NAME column in the                                         // people database to...    new int[] {android.R.id.text1}); // The "text1" view defined in                                     // the XML template                                         adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);s2.setAdapter(adapter2);

The android:inputType attribute has three pieces: The class is the overall interpretation of characters. The currently supported classes are text (plain text), number (decimal number), phone (phone number), and datetime (a date or time). The variation is a further refinement on the class. In the attribute you will normally specify the class and variant together, with the class as a prefix. For example, textEmailAddress is a text field where the user will enter something that is an e-mail address (foo@bar.com) so the key layout will have an '@' character in easy access, and numberSigned is a numeric field with a sign. If only the class is specified, then you get the default/generic variant. Additional flags can be specified that supply further refinement. These flags are specific to a class. For example, some flags for the text class are textCapSentences, textAutoCorrect, and textMultiline.

    <EditText android:id="@+id/edtInput"        android:layout_width="0dip"        android:layout_height="wrap_content"        android:layout_weight="1"        android:inputType="textShortMessage|textAutoCorrect|textCapSentences|textMultiLine"        android:imeOptions="actionSend|flagNoEnterAction"        android:maxLines="4"        android:maxLength="2000"        android:hint="@string/compose_hint"/>

软键盘软件公司 Swype 表示自己的技术将在年底前被用在 1000 万部智能手机上。 该公司 CEO Mike McSherry 在接受采访时表示美国四大移动运营商今夏都会提供预知 Swype 输入法的手机。欧亚和南美洲的移动运营商也将提供同类产品。他说：“我们希望让它（Swype）成为每一款触屏产品的标准键盘，现在已经有了一些大的进展”

Google Chrome to Phone Extension is a project consisting of a Chrome Extension, Android App, and supporting AppEngine server that enables users to send links from their Chrome desktop browser to their Android device using Android's Cloud to Device Messaging service.

// Get display for detecting the phone orientation display = ((WindowManager) getSystemService(WINDOW_SERVICE)).getDefaultDisplay(); // Get the orientation int orientation = display.getOrientation();

android.view.Display class provide a simple way to determine the phone orientation.

施密特说：“按照目前发展趋势，Android手机有望在全球手机市场扮演第一或第二的角色。”除 向手机厂商提供Android软件外，谷歌还发布了自有品牌智能手机Nexus One。 施密特表示：“我们的合作伙伴每天Android手机出货量约为6.5万部。如果你经常访问博客网站，就会发现一些有关Android手机出 货量的估计数字远远低于实际情况。”

美国市场研究公司NPD近日发布的统计数据显示，今年第一季度期间，Android手机在美国市场 的销量已超过iPhone，占据该季度美国智能手机总销量的28%，iPhone相应份额为21%，而加拿大智能手机制造商RIM的黑莓 (BlackBerry)手机相应市场份额仍居第一，为36%。

施密特周四表示：“我们的手机市场战略与其他厂商不同。我 们向各大手机厂商免费提供Android软件，这是具有变革意义的举动。我们希望建立起一个开放环境，这一点与其他手机厂商的市场策略正好相反。” 谷歌联合创始人拉里·佩奇(Larry Page)周四也出席了谷歌股东年度大会。他当天表示，采用Android软件的智能手机型号数量增加后，将有利于谷歌搜索总量的增长，并使谷歌其他业务 也受益，“智能手机产品逐步成熟后，我们将能够制定出相应盈利方案。” 施密特称，自 己同意佩奇的看法，“虽然我们已向各大手机厂商免费提供Android软件，但与Android手机平台相关的应用程序和服务具有巨大增长潜力。今后 5~10年内，手机应用程序和服务将成为业务范围极为广泛的产业，其市场价值不容小视。”