Android编程14个很有用的代码片段

http://www.apkbus.com/android-104070-1-1.html

1、查看是否有存储卡插入

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String status=Environment.getExternalStorageState();     if ( status.equals ( Enviroment.MEDIA_MOUNTED ) )  {      说明有SD卡插入  }

2、让某个Activity透明

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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.

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TextView msgTextView = (TextView)findViewById(R.id.msg);     msgTextView.setText(R.string.push_me);

4、发送短信

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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

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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);

6、显示toast

1 2	Toast.makeText(this._getApplicationContext(), R.string._item, Toast.LENGTH_SHORT).show();

7、发送Mail

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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

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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

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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

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

11、清空手机上cookie

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CookieSyncManager.createInstance (getApplicationContext() );     CookieManager.getInstance().removeAllCookie();

12、建立GPRS连接

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//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

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public class Setting extends PreferenceActivity  {      public void onCreate ( Bundle savedInstanceState )          {              super.onCreate ( savedInstanceState );              addPreferencesFromResource ( R.xml.settings );       }  }

14、通过HttpClient从指定server获取数据

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DefaultHttpClient httpClient = new DefaultHttpClient();               HttpGet method = new HttpGet(“/templets/default/index.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();               }        }