一个常用Android工具类

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;  }  }