整理出15个Android很有用的代码片段(技巧)ophone

1：查看是否有存储卡插入String status=Environment.getExternalStorageState();if(status.equals(Enviroment.MEDIA_MOUNTED)) 说明有SD卡插入 2：让某个Activity透明OnCreate中不设Layoutthis.setTheme(R.style.Theme_Transparent);以下是Theme_Transparent的定义（注意transparent_bg是一副透明的图片）3：在屏幕元素中设置句柄使用Activity.findViewById来取得屏幕上的元素的句柄. 使用该句柄您可以设置或获取任何该对象外露的值.TextView msgTextView = (TextView)findViewById(R.id.msg); msgTextView.setText(R.string.push_me);4:发送短信 String body=”this is mms demo”; Intent mmsintent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts(”smsto”, number, null)); mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_BODY, body); mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_COMPOSE_MODE, true); mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_EXIT_ON_SENT, true); startActivity(mmsintent); 5:发送彩信 StringBuilder sb = new StringBuilder(); sb.append(”file://”); sb.append(fd.getAbsoluteFile()); Intent intent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts(”mmsto”, number, null)); // Below extra datas are all optional. intent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_SUBJECT, subject); intent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_BODY, body); intent.putExtra(Messaging.KEY_ACTION_SENDTO_CONTENT_URI, sb.toString()); intent.putExtra(Messaging.KEY_ACTION_SENDTO_COMPOSE_MODE, composeMode); intent.putExtra(Messaging.KEY_ACTION_SENDTO_EXIT_ON_SENT, exitOnSent); startActivity(intent);7：发送Mail mime = “img/jpg”; shareIntent.setDataAndType(Uri.fromFile(fd), mime); shareIntent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(fd)); shareIntent.putExtra(Intent.EXTRA_SUBJECT, subject); shareIntent.putExtra(Intent.EXTRA_TEXT, body);8:注册一个BroadcastReceiverregisterReceiver(mMasterResetReciever, new IntentFilter(”oms.action.MASTERRESET”));private BroadcastReceiver mMasterResetReciever = new BroadcastReceiver() { public void onReceive(Context context, Intent intent){ String action = intent.getAction(); if(”oms.action.MASTERRESET”.equals(action)){ RecoverDefaultConfig(); } };9:定义ContentObserver，监听某个数据表private ContentObserver mDownloadsObserver = new DownloadsChangeObserver(Downloads.CONTENT_URI);private class DownloadsChangeObserver extends ContentObserver { public DownloadsChangeObserver(Uri uri) { super(new Handler()); } @Override public void onChange(boolean selfChange) {｝ 10:获得 手机UApublic String getUserAgent() String user_agent = ProductProperties.get(ProductProperties.USER_AGENT_KEY, null); return user_agent; }11：清空手机上CookieCookieSyncManager.createInstance(getApplicationContext()); CookieManager.getInstance().removeAllCookie();12：建立GPRS连接 //Dial the GPRS link. private boolean openDataConnection() { // Set up data connection. DataConnection conn = DataConnection.getInstance(); if (connectMode == 0) { ret = conn.openConnection(mContext, “cmwap”, “cmwap”, “cmwap”); } else { ret = conn.openConnection(mContext, “cmnet”, “”, “”); } }13：PreferenceActivity 用法public class Setting extends PreferenceActivity｛ public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.settings)； }｝Setting.xml: android:key=”seting2″ android:title=”@string/seting2″ android:summary=”@string/seting2″/> android:key=”seting1″ android:title=”@string/seting1″ android:summaryOff=”@string/seting1summaryOff” android:summaryOn=”@stringseting1summaryOff”/>14:通过HttpClient从指定server获取数据 DefaultHttpClient httpClient = new DefaultHttpClient(); HttpGet method = new HttpGet(“http://www.baidu.com/1.html”); HttpResponse resp; Reader reader = null; try { // AllClientPNames.TIMEOUT HttpParams params = new BasicHttpParams(); params.setIntParameter(AllClientPNames.CONNECTION_TIMEOUT, 10000); httpClient.setParams(params); resp = httpClient.execute(method); int status = resp.getStatusLine().getStatusCode(); if (status != HttpStatus.SC_OK) return false; // HttpStatus.SC_OK; return true; } catch (ClientProtocolException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { if (reader != null) try { reader.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); }15:显示toastToast.makeText(this._getApplicationContext(), R.string._item, Toast.LENGTH_SHORT).show();