Android 开发常用代码片段

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
//创建电话管理

TelephonyManager tm = (TelephonyManager)

//与手机建立连接
activity.getSystemService(Context.TELEPHONY_SERVICE);

//获取手机号码

String phoneId = tm.getLine1Number();

//记得在manifest file中添加
    <uses-permission
android:name="android.permission.READ_PHONE_STATE" />

//程序在模拟器上无法实现，必须连接手机

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[]{"[email protected]","[email protected]}); 
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("http://vaiyanzi.cnblogs.com"));

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);