15个Android很有用的代码片段(技巧)

donaldzch 贡献于2012-01-13

作者 czhu  创建于2010-07-20 09:07:00   修改者czhu  修改于2010-07-20 09:08:00字数3945

文档摘要:15个Android很有用的代码片段
关键词:

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();

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