android很实用的工具类，android工具类,public class

android很实用的工具类，android工具类,public class

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 &amp; 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;    }}