13个简单有用的android开发代码

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

在OnCreate 中不设Layout,然后this.setTheme(R.style.Theme_Transparent);

3：获取屏幕宽高

DisplayMetrics dm = new DisplayMetrics();
//获取窗口属性
getWindowManager().getDefaultDisplay().getMetrics(dm);
int screenWidth = dm.widthPixels;
int screenHeight = dm.heightPixels;

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：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);

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();
            }
        }
    };

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) {｝
        }

9:获得 手机UA

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();

11：建立GPRS 连接

private boolean openDataConnection() {   

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”/>

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();  

 }   

}