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.

1 2	`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

1	`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

1 2	`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

setting.xml:

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

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(); 
              } 
          } 