android 开发实用

Android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.}

2：让某个Activity透明

OnCreate中不设Layoutthis.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.

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

4：发送短信

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

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

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);  
             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

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.    };  
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

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.    
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

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

10：清空手机上Cookie

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

11：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. }  
   //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”, “”, “”);
            }
    }

12：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.｝   
8.Setting.xml:   
9.            android:key=”seting2″   
10.            android:title=”@string/seting2″   
11.            android:summary=”@string/seting2″/>   
12.            android:key=”seting1″   
13.            android:title=”@string/seting1″   
14.            android:summaryOff=”@string/seting1summaryOff”   
15.            android:summaryOn=”@stringseting1summaryOff”/>  
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

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.}  
             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();
                }
            }

14：显示toast

Java代码

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

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