Android编程14个实用的代码片段

jopen 9年前

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);   


6、显示toast

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


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(“/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();                  }           }