Android编程14个很有用的代码片段

1、查看是否有存储卡插入 
[java]  
String status=Environment.getExternalStorageState();   
  
if ( status.equals ( Enviroment.MEDIA_MOUNTED ) )   
{   
    说明有SD卡插入   
}   
 
2、让某个Activity透明 
[java] 
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.
[java]  
TextView msgTextView = (TextView)findViewById(R.id.msg);   
  
msgTextView.setText(R.string.push_me);   
 
4、发送短信
[java]  
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
[java] 
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
[java] view plaincopy
Toast.makeText(this._getApplicationContext(), R.string._item, Toast.LENGTH_SHORT).show();  
  
   
 
7、发送Mail
[java] 
    
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
[java]  
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
[java] 
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 
[java]  
public String getUserAgent()   
{   
    String user_agent = ProductProperties.get(ProductProperties.USER_AGENT_KEY, null);   
      
    return user_agent;   
}   
 
11、清空手机上cookie 
[java] 
CookieSyncManager.createInstance (getApplicationContext() );   
  
CookieManager.getInstance().removeAllCookie();   
 
12、建立GPRS连接 
[java]  
//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 
[java] 
public class Setting extends PreferenceActivity   
{   
    public void onCreate ( Bundle savedInstanceState )   
        {   
            super.onCreate ( savedInstanceState );   
            addPreferencesFromResource ( R.xml.settings );    
    }   
}   
Setting.xml:

补充：移动开发 , Android ,