Android编程14个很有用的代码片段

1：查看是否有存储卡插入 


1.String status=Environment.getExternalStorageState();
2.if(status.equals(Enviroment.MEDIA_MOUNTED))
3.{
4.说明有SD卡插入
5.}


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2：让某个Activity透明 


1.OnCreate中不设Layout
2.
3.this.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. 


1.TextView msgTextView = (TextView)findViewById(R.id.msg);
2.msgTextView.setText(R.string.push_me);


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4:发送短信 


1.String body=”this is mms demo”;
2.
3.Intent mmsintent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts(”smsto”, number, null));
4.mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_BODY, body);
5.mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_COMPOSE_MODE, true);
6.mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_EXIT_ON_SENT, true);
7.startActivity(mmsintent);


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5:发送彩信 


1.StringBuilder sb = new StringBuilder();
2.
3.sb.append(”file://”);
4.
5.sb.append(fd.getAbsoluteFile());
6.
7.Intent intent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts(”mmsto”, number, null));
8.// Below extra datas are all optional.
9.intent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_SUBJECT, subject);
10.intent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_BODY, body);
11.intent.putExtra(Messaging.KEY_ACTION_SENDTO_CONTENT_URI, sb.toString());
12.intent.putExtra(Messaging.KEY_ACTION_SENDTO_COMPOSE_MODE, composeMode);
13.intent.putExtra(Messaging.KEY_ACTION_SENDTO_EXIT_ON_SENT, exitOnSent);
14.
15.startActivity(intent);


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6:显示toast 


1.Toast.makeText(this._getApplicationContext(), R.string._item, Toast.LENGTH_SHORT).show();


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7：发送Mail 



1.  mime = “img/jpg”;
2.            shareIntent.setDataAndType(Uri.fromFile(fd), mime);
3.            shareIntent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(fd));
4.            shareIntent.putExtra(Intent.EXTRA_SUBJECT, subject);
5.            shareIntent.putExtra(Intent.EXTRA_TEXT, body);


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8:注册一个BroadcastReceiver 


1.registerReceiver(mMasterResetReciever, new IntentFilter(”OMS.action.MASTERRESET”));
2.private BroadcastReceiver mMasterResetReciever = new BroadcastReceiver() {
3.        public void onReceive(Context context, Intent intent){
4.            String action = intent.getAction();
5.            if(”oms.action.MASTERRESET”.equals(action)){
6.                RecoverDefaultConfig();
7.            }
8.        }
9.    };


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9:定义ContentObserver，监听某个数据表 


1.private ContentObserver mDownloadsObserver = new DownloadsChangeObserver(Downloads.CONTENT_URI);
2.private class DownloadsChangeObserver extends ContentObserver {
3.        public DownloadsChangeObserver(Uri uri) {
4.            super(new Handler());
5.        }
6.        @Override
7.        public void onChange(boolean selfChange) {｝
8.        }
9.


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10:获得 手机UA 


1.public String getUserAgent()
2.    {
3.           String user_agent = ProductProperties.get(ProductProperties.USER_AGENT_KEY, null);
4.            return user_agent;
5.    }


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11：清空手机上cookie 


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


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12：建立GPRS连接 



1.//Dial the GPRS link.
2.    private boolean openDataConnection() {
3.        // Set up data connection.
4.        DataConnection conn = DataConnection.getInstance();
5.            if (connectMode == 0) {
6.                ret = conn.openConnection(mContext, “cmwap”, “cmwap”, “cmwap”);
7.            } else {
8.                ret = conn.openConnection(mContext, “cmnet”, “”, “”);
9.            }
10.    }


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13：PreferenceActivity 用法 


1.public class Setting extends PreferenceActivity
2.｛
3.    public void onCreate(Bundle savedInstanceState) {
4.        super.onCreate(savedInstanceState);
5.        addPreferencesFromResource(R.xml.settings)；
6.    }
7.｝


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Setting.xml: 



1.   Android: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 



1.  DefaultHttpClient httpClient = new DefaultHttpClient();
2.            HttpGet method = new HttpGet(“http://www.baidu.com/1.html”);
3.            HttpResponse resp;
4.            Reader reader = null;
5.            try {
6.                // AllClientPNames.TIMEOUT
7.                HttpParams params = new BasicHttpParams();
8.                params.setIntParameter(AllClientPNames.CONNECTION_TIMEOUT, 10000);
9.                httpClient.setParams(params);
10.                resp = httpClient.execute(method);
11.                int status = resp.getStatusLine().getStatusCode();
12.                if (status != HttpStatus.SC_OK) return false;
13.                // HttpStatus.SC_OK;
14.                return true;
15.            } catch (ClientProtocolException e) {
16.                // TODO Auto-generated catch block
17.                e.printStackTrace();
18.            } catch (IOException e) {
19.                // TODO Auto-generated catch block
20.                e.printStackTrace();
21.            } finally {
22.                if (reader != null) try {
23.                    reader.close();
24.                } catch (IOException e) {
25.                    // TODO Auto-generated catch block
26.                    e.printStackTrace();
27.                }
28.            }