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.

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 

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(); 
                } 
            } 

本文摘自：http://www.cmd100.com/bbs/thread-4674-1-1.html