这些片段在Android编程中很有用

网上搜的，感觉挺好，希望能给和我一样的初学者带来方便

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.
view sourceprint?1 TextView msgTextView = (TextView)findViewById(R.id.msg);  

msgTextView.setText(R.string.push_me);


4：发送短信
view sourceprint?1 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
view sourceprint?01 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
view sourceprint?1 Toast.makeText(this._getApplicationContext(), R.string._item, Toast.LENGTH_SHORT).show();


7：发送Mail

view sourceprint?1 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
view sourceprint?1 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

view sourceprint?1 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
view sourceprint?1 public String getUserAgent()  

     {  

            String user_agent = ProductProperties.get(ProductProperties.USER_AGENT_KEY, null);  

             return user_agent;  

     }


11：清空手机上cookie

view sourceprint?1 CookieSyncManager.createInstance(getApplicationContext());  

         CookieManager.getInstance().removeAllCookie();


12：建立GPRS连接

view sourceprint?01 //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
setting.xml:

view sourceprint?1 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
view sourceprint?01 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();  

               }  

           }