Android很有用的代码片段

 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
}

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);

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);

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)

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：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);

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);
7：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();
            }
        }
    }

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(); } } }
8：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) {｝
        }

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) {｝ }

 
9：获得 手机UA

public String getUserAgent()
    {
           String user_agent = ProductProperties.get(ProductProperties.USER_AGENT_KEY, null);
            return user_agent;
    }

public String getUserAgent() { String user_agent = ProductProperties.get(ProductProperties.USER_AGENT_KEY, null); return user_agent; }

10：清空手机上Cookie

CookieSyncManager.createInstance(getApplicationContext());
        CookieManager.getInstance().removeAllCookie();

CookieSyncManager.createInstance(getApplicationContext()); CookieManager.getInstance().removeAllCookie();11：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”, “”, “”);
           }
   }

//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”, “”, “”); } }


12：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”/>

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”/>
13：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();
                }
            }

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(); } }