android实用工具类分享(获取内存/检查网络/屏幕高度/手机分辨率)

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;
 }
}