整理出15个Android很有用的代码片段

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Layout

this.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BroadcastReceiver
registerReceiver(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UA

public String getUserAgent(){ String user_agent = ProductProperties.get(ProductProperties.USER_AGENT_KEY, null); return user_agent;}

11：清空手机上Cookie

CookieSyncManager.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toast

Toast.makeText(this._getApplicationContext(), R.string._item, Toast.LENGTH_SHORT).show();