Android 开发常用代码片段

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1、图片旋转

Bitmap bitmapOrg = BitmapFactory.decodeResource(this.getContext().getResources(), R.drawable.moon);
Matrix matrix = new Matrix();
matrix.postRotate(-90);//旋转的角度
 
Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0,
   bitmapOrg.getWidth(), bitmapOrg.getHeight(), matrix, true);
BitmapDrawable bmd = new BitmapDrawable(resizedBitmap);

2、获取手机号码

<p>//创建电话管理</p><p>TelephonyManager tm = (TelephonyManager)</p><p>//与手机建立连接
activity.getSystemService(Context.TELEPHONY_SERVICE);</p><p>//获取手机号码</p><p>String phoneId = tm.getLine1Number();</p><p>//记得在manifest file中添加
   <uses-permission
android:name="android.permission.READ_PHONE_STATE" /></p><p>//程序在模拟器上无法实现，必须连接手机</p>

3.格式化string.xml 中的字符串

// in strings.xml..
<string name="my_text">Thanks for visiting %s. You age is %d!</string>
// and in the java code:
String.format(getString(R.string.my_text), "oschina", 33);

4、android设置全屏的方法
A.在java代码中设置

/** 全屏设置，隐藏窗口所有装饰 */
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
   WindowManager.LayoutParams.FLAG_FULLSCREEN);

B、在AndroidManifest.xml中配置

<activity android:name=".Login.NetEdit"  android:label="@string/label_net_Edit" 
   android:screenOrientation="portrait" android:theme="@android:style/Theme.Black.NoTitleBar.Fullscreen">
 <intent-filter>
  <action android:name="android.intent.Net_Edit" />
  <category android:name="android.intent.category.DEFAULT" />
 </intent-filter>
</activity>

5、设置Activity为Dialog的形式


在AndroidManifest.xml中配置Activity节点是配置theme如下：
android:theme="@android:style/Theme.Dialog"

6、检查当前网络是否连上


ConnectivityManager con=(ConnectivityManager)getSystemService(Activity.CONNECTIVITY_SERVICE);  
 
boolean wifi=con.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isConnectedOrConnecting();  
boolean internet=con.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).isConnectedOrConnecting(); 
在AndroidManifest.xml 增加权限：
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

7、检测某个Intent是否有效


public static boolean isIntentAvailable(Context context, String action) {
   final PackageManager packageManager = context.getPackageManager();
   final Intent intent = new Intent(action);
   List<ResolveInfo> list =
   packageManager.queryIntentActivities(intent,
   PackageManager.MATCH_DEFAULT_ONLY);
   return list.size() > 0;
}

8、android 拨打电话


try {
   Intent intent = new Intent(Intent.ACTION_CALL);
   intent.setData(Uri.parse("tel:+110"));
   startActivity(intent);
} catch (Exception e) {
   Log.e("SampleApp", "Failed to invoke call", e);
}

9、android中发送Email


Intent i = new Intent(Intent.ACTION_SEND);  
//i.setType("text/plain"); //模拟器请使用这行
i.setType("message/rfc822") ; // 真机上使用这行
i.putExtra(Intent.EXTRA_EMAIL, new String]{"<a href="mailto:test@gmail.com" target="_blank">test@gmail.com","test@163.com</a>});  
i.putExtra(Intent.EXTRA_SUBJECT,"subject goes here");  
i.putExtra(Intent.EXTRA_TEXT,"body goes here");  
startActivity(Intent.createChooser(i, "Select email application."));

10、android中打开浏览器


Intent viewIntent = new 
   Intent("android.intent.action.VIEW",Uri.parse("<a href="http://vaiyanzi.cnblogs.com" target="_blank">http://vaiyanzi.cnblogs.com</a>"));
startActivity(viewIntent);

11、android 获取设备唯一标识码

String android_id = Secure.getString(getContext().getContentResolver(), Secure.ANDROID_ID);

12、android中获取IP地址

public String getLocalIpAddress() {
   try {
   for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); 
  en.hasMoreElements();) {
   NetworkInterface intf = en.nextElement();
   for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); 
  enumIpAddr.hasMoreElements();) {
   InetAddress inetAddress = enumIpAddr.nextElement();
   if (!inetAddress.isLoopbackAddress()) {
   return inetAddress.getHostAddress().toString();
   }
   }
   }
   } catch (SocketException ex) {
   Log.e(LOG_TAG, ex.toString());
   }
   return null;
}

13、android获取存储卡路径以及使用情况

/** 获取存储卡路径 */ 
File sdcardDir=Environment.getExternalStorageDirectory(); 
/** StatFs 看文件系统空间使用情况 */ 
StatFs statFs=new StatFs(sdcardDir.getPath()); 
/** Block 的 size*/ 
Long blockSize=statFs.getBlockSize(); 
/** 总 Block 数量 */ 
Long totalBlocks=statFs.getBlockCount(); 
/** 已使用的 Block 数量 */ 
Long availableBlocks=statFs.getAvailableBlocks();

14 android中添加新的联系人


private Uri insertContact(Context context, String name, String phone) {
   
   ContentValues values = new ContentValues();
   values.put(People.NAME, name);
   Uri uri = getContentResolver().insert(People.CONTENT_URI, values);
   Uri numberUri = Uri.withAppendedPath(uri, People.Phones.CONTENT_DIRECTORY);
   values.clear();
   
   values.put(Contacts.Phones.TYPE, People.Phones.TYPE_MOBILE);
   values.put(People.NUMBER, phone);
   getContentResolver().insert(numberUri, values);
   
   return uri;
}

15、查看电池使用情况

Intent intentBatteryUsage = new Intent(Intent.ACTION_POWER_USAGE_SUMMARY);        
startActivity(intentBatteryUsage);

16、获取进程号


ActivityManager mActivityManager = (ActivityManager) this.getSystemService(ACTIVITY_SERVICE);
List<ActivityManager.RunningAppProcessInfo> mRunningProcess = mActivityManager.getRunningAppProcesses();

int i = 1;
for (ActivityManager.RunningAppProcessInfo amProcess : mRunningProcess) {
Log.e(“homer Application”, (i++) + " PID = " + amProcess.pid + "; processName = " + amProcess.processName);
}