Android编程14个很有用的代码片段
1、查看是否有存储卡插入
1String status=Environment.getExternalStorageState();
2
3if ( status.equals ( Enviroment.MEDIA_MOUNTED ) )
4{
5 说明有SD卡插入
6}
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2、让某个Activity透明
1OnCreate中不设Layout
2
3this.setTheme(R.style.Theme_Transparent);
4
5以下是Theme_Transparent的定义（注意transparent_bg是一副透明的图片）
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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.
1TextView msgTextView = (TextView)findViewById(R.id.msg);
2
3msgTextView.setText(R.string.push_me);
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4、发送短信
1String body=”this is mms demo”;
2
3Intent mmsintent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts(”smsto”, number, null));
4
5mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_BODY, body);
6mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_COMPOSE_MODE, true);
7mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_EXIT_ON_SENT, true);
8
9startActivity(mmsintent);
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5、发送彩信
01StringBuilder sb = new StringBuilder();
02
03sb.append(”file://”);
04
05sb.append(fd.getAbsoluteFile());
06
07Intent intent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts(”mmsto”, number, null));
08
09// Below extra datas are all optional.
10intent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_SUBJECT, subject);
11intent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_BODY, body);
12intent.putExtra(Messaging.KEY_ACTION_SENDTO_CONTENT_URI, sb.toString());
13intent.putExtra(Messaging.KEY_ACTION_SENDTO_COMPOSE_MODE, composeMode);
14intent.putExtra(Messaging.KEY_ACTION_SENDTO_EXIT_ON_SENT, exitOnSent);
15
16startActivity(intent);
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6、显示toast
1Toast.makeText(this._getApplicationContext(), R.string._item, Toast.LENGTH_SHORT).show();
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7、发送Mail
01
02mime = “img/jpg”;
03
04shareIntent.setDataAndType(Uri.fromFile(fd), mime);
05
06shareIntent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(fd));
07
08shareIntent.putExtra(Intent.EXTRA_SUBJECT, subject);
09
10shareIntent.putExtra(Intent.EXTRA_TEXT, body);
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8、注册一个BroadcastReceiver
01registerReceiver(mMasterResetReciever, new IntentFilter(”OMS.action.MASTERRESET”));
02
03private BroadcastReceiver mMasterResetReciever = new BroadcastReceiver()
04{
05 public void onReceive(Context context, Intent intent)
06 {
07 String action = intent.getAction();
08
09 if (”oms.action.MASTERRESET”.equals(action) )
10 {
11 RecoverDefaultConfig();
12 }
13 }
14};
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9、定义ContentObserver，监听某个数据表
01private ContentObserver mDownloadsObserver = new DownloadsChangeObserver(Downloads.CONTENT_URI);
02
03private class DownloadsChangeObserver extends ContentObserver
04{
05 public DownloadsChangeObserver(Uri uri)
06 {
07 super(new Handler());
08 }
09
10 @Override
11 public void onChange(boolean selfChange) {}
12
13}
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10、获得 手机UA
1public String getUserAgent()
2{
3 String user_agent = ProductProperties.get(ProductProperties.USER_AGENT_KEY, null);
4
5 return user_agent;
6}
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11、清空手机上cookie
1CookieSyncManager.createInstance (getApplicationContext() );
2
3CookieManager.getInstance().removeAllCookie();
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12、建立GPRS连接
01//Dial the GPRS link.
02private boolean openDataConnection()
03{
04 // Set up data connection.
05 DataConnection conn = DataConnection.getInstance();
06
07 if ( connectMode == 0 )
08 {
09 ret = conn.openConnection ( mContext, “cmwap”, "cmwap”, "cmwap” );
10 }
11 else
12 {
13 ret = conn.openConnection(mContext, “cmnet”, "", "");
14 }
15}
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13、PreferenceActivity 用法
1public class Setting extends PreferenceActivity
2{
3 public void onCreate ( Bundle savedInstanceState )
4 {
5 super.onCreate ( savedInstanceState );
6 addPreferencesFromResource ( R.xml.settings );
7 }
8}
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Setting.xml:
1Android:key=”seting2″
2 android:title=”@string/seting2″
3 android:summary=”@string/seting2″/>
4 android:key=”seting1″
5 android:title=”@string/seting1″
6 android:summaryOff=”@string/seting1summaryOff”
7 android:summaryOn=”@stringseting1summaryOff”/>
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14、通过HttpClient从指定server获取数据
01DefaultHttpClient httpClient = new DefaultHttpClient();
02 HttpGet method = new HttpGet(“http://www.ligotop.com/index.html”);
03 HttpResponse resp;
04 Reader reader = null;
05 try {
06 // AllClientPNames.TIMEOUT
07 HttpParams params = new BasicHttpParams();
08 params.setIntParameter(AllClientPNames.CONNECTION_TIMEOUT, 10000);
09
10 httpClient.setParams(params);
11 resp = httpClient.execute(method);
12 int status = resp.getStatusLine().getStatusCode();
13
14 if (status != HttpStatus.SC_OK)
15 {
16 return false;
17 }
18 // HttpStatus.SC_OK;
19 return true;
20 }
21 catch (ClientProtocolException e)
22 {
23 // TODO Auto-generated catch block
24 e.printStackTrace();
25 <