15个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 } 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”);
        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();

http://chunpeng.javaeye.com/blog/523722