public class CommonUtil {  public static boolean hasSDCard() {   String status = Environment.getExternalStorageState();   return status.equals(Environment.MEDIA_MOUNTED);  }  /**   * 获取最大内存   *   * @return   */  public static long getMaxMemory() {   return Runtime.getRuntime().maxMemory() / 1024;  }  /**   * 检查网络   *   * @param context   * @return   */  public static boolean checkNetState(Context context) {   boolean netstate = false;   ConnectivityManager connectivity = (ConnectivityManager) context     .getSystemService(Context.CONNECTIVITY_SERVICE);   if (connectivity != null) {    NetworkInfo[] info = connectivity.getAllNetworkInfo();    if (info != null) {     for (int i = 0; i < info.length; i++) {      if (info[i].getState() == NetworkInfo.State.CONNECTED) {       netstate = true;       break;      }     }    }   }   return netstate;  }  public static void showToast(Context context, String tip) {   Toast.makeText(context, tip, Toast.LENGTH_SHORT).show();  }  public static DisplayMetrics metric = new DisplayMetrics();  /**   * 得到屏幕高度   *   * @param context   * @return   */  public static int getScreenHeight(Activity context) {   context.getWindowManager().getDefaultDisplay().getMetrics(metric);   return metric.heightPixels;  }  /**   * 得到屏幕宽度   *   * @param context   * @return   */  public static int getScreenWidth(Activity context) {   context.getWindowManager().getDefaultDisplay().getMetrics(metric);   return metric.widthPixels;  }  /**   * 根据手机的分辨率从 dp 的单位 转成为 px(像素)   */  public static int dip2px(Context context, float dpValue) {   final float scale = context.getResources().getDisplayMetrics().density;   return (int) (dpValue * scale + 0.5f);  }  /**   * 根据手机的分辨率从 px(像素) 的单位 转成为 dp   */  public static int px2dip(Context context, float pxValue) {   final float scale = context.getResources().getDisplayMetrics().density;   return (int) (pxValue / scale + 0.5f);  }  /**   * 查询手机内非系统应用   *   * @param context   * @return   */  public static List<PackageInfo> getAllApps(Context context) {   List<PackageInfo> apps = new ArrayList<PackageInfo>();   PackageManager pManager = context.getPackageManager();   // 获取手机内所有应用   List<PackageInfo> paklist = pManager.getInstalledPackages(0);   for (int i = 0; i < paklist.size(); i++) {    PackageInfo pak = (PackageInfo) paklist.get(i);    // 判断是否为非系统预装的应用程序    if ((pak.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) <= 0) {     // customs applications     apps.add(pak);    }   }   return apps;  }  public static Bitmap zoomBitmap(Bitmap bitmap, int width, int height) {   int w = bitmap.getWidth();   int h = bitmap.getHeight();   Matrix matrix = new Matrix();   float scaleWidth = ((float) width / w);   float scaleHeight = ((float) height / h);   matrix.postScale(scaleWidth, scaleHeight);   Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, w, h, matrix, true);   return newbmp;  }  /**   * 获取版本号和版本次数   *   * @param context   * @return   */  public static String getVersionCode(Context context, int type) {   try {    PackageInfo pi = context.getPackageManager().getPackageInfo(      context.getPackageName(), 0);    if (type == 1) {     return String.valueOf(pi.versionCode);    } else {     return pi.versionName;    }   } catch (NameNotFoundException e) {    e.printStackTrace();    return null;   }  }  // 通过Service的类名来判断是否启动某个服务  public static boolean messageServiceIsStart(    List<ActivityManager.RunningServiceInfo> mServiceList,    String className) {   for (int i = 0; i < mServiceList.size(); i++) {    if (className.equals(mServiceList.get(i).service.getClassName())) {     return true;    }   }   return false;  } }