1.android：整理出15个Android很有用的代码片段(技巧)

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);
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(“http://www.baidu.com/1.html”);

           
4000
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();

                }

            }
15:显示toast
Toast.makeText(this._getApplicationContext(), R.string._item, Toast.LENGTH_SHORT).show();