Android（判断wifi是否开启，手机屏幕状态，sdcard是否被拔出，设置全屏)

工作中遇到的问题要注意总结，我在工作中遇到了问题，现在抽空简单整理一下；

 

       第一个问题：判断手机当前上网用的是sim卡还是wifi，我写了一个封装的方法，以后可以拿来用：

/**
 * check the internet is
 * mobile or wifi
 * add by wangxianming
 * in 2012-03-22
 */
private boolean checkWifi() {
    boolean isWifiConnect = true;
    ConnectivityManager cm = (ConnectivityManager)mContext.getSystemService(Context.CONNECTIVITY_SERVICE);

/** * check the internet is * mobile or wifi * add by wangxianming * in 2012-03-22 */ private boolean checkWifi() { boolean isWifiConnect = true; ConnectivityManager cm = (ConnectivityManager)mContext.getSystemService(Context.CONNECTIVITY_SERVICE);

//check the networkInfos numbers
NetworkInfo[] networkInfos = cm.getAllNetworkInfo();
for (int i = 0; i<networkInfos.length; i++) {
    if (networkInfos[i].getState() == NetworkInfo.State.CONNECTED) {
       if(networkInfos[i].getType() == cm.TYPE_MOBILE) {
           isWifiConnect = false;
       }
       if(networkInfos[i].getType() == cm.TYPE_WIFI) {
           isWifiConnect = true;
       }
    }
}
return isWifiConnect;

//check the networkInfos numbers NetworkInfo[] networkInfos = cm.getAllNetworkInfo(); for (int i = 0; i<networkInfos.length; i++) { if (networkInfos[i].getState() == NetworkInfo.State.CONNECTED) { if(networkInfos[i].getType() == cm.TYPE_MOBILE) { isWifiConnect = false; } if(networkInfos[i].getType() == cm.TYPE_WIFI) { isWifiConnect = true; } } } return isWifiConnect; }

 

 

        第二个例子:判断当前的手机屏幕是否开启了旋转屏幕这个选项:

        /**
     * ACCELEROMETER_ROTATION---->explain:
     *
     * Control whether the accelerometer will be
     * used to change screen orientation.
     * If 0, it will not be used unless explicitly
     * requested by the application;
     * if 1, it will be used by default
     * unless explicitly disabled by the application.
     * Constant Value: "accelerometer_rotation"
     */
    systemGravity = Settings.System.getInt(this
.getContentResolver(),
Settings.System.ACCELEROMETER_ROTATION);//1 is open;0 is close;

/** * ACCELEROMETER_ROTATION---->explain: * * Control whether the accelerometer will be * used to change screen orientation. * If 0, it will not be used unless explicitly * requested by the application; * if 1, it will be used by default * unless explicitly disabled by the application. * Constant Value: "accelerometer_rotation" */ systemGravity = Settings.System.getInt(this .getContentResolver(), Settings.System.ACCELEROMETER_ROTATION);//1 is open;0 is close;

 

 

         第三个是在代码中注册监听内存卡状态的广播：     

IntentFilter intentFilter=new IntentFilter);
intentFilter.addAction(Intent.ACTION_MEDIA_UNMOUNTED);
intentFilter.addAction(Intent.ACTION_MEDIA_EJECT);
intentFilter.addAction(Intent.ACTION_MEDIA_REMOVED);
intentFilter.addAction(Intent.ACTION_MEDIA_BAD_REMOVAL);
registerReceiver(sdcardListener,intentFilter);

IntentFilter intentFilter=new IntentFilter); intentFilter.addAction(Intent.ACTION_MEDIA_UNMOUNTED); intentFilter.addAction(Intent.ACTION_MEDIA_EJECT); intentFilter.addAction(Intent.ACTION_MEDIA_REMOVED); intentFilter.addAction(Intent.ACTION_MEDIA_BAD_REMOVAL); registerReceiver(sdcardListener,intentFilter);

          有registerReceiver（）注册广播，就有unregisterReceiver（）方法，他们是成对出现的。

          如果在onCreate（）方法中注册广播，就在onDestroy（）方法中释放。

          如果在onResume（）方法中注册广播，就在onPause（）方法中释放。

 

          在代码中写个内部类的广播：

<span style="font-size:16px;color:#000000;">private final BroadcastReceiver sdcardListener=new BroadcastReceiver() {

        public void onReceive(Context context, Intent intent) {
            Toast.makeText(SummaryAppMainActivityActivity.this, R.string.sd_removed, 2000).show();
        }
    };</span>

<span style="font-size:16px;color:#000000;">private final BroadcastReceiver sdcardListener=new BroadcastReceiver() { public void onReceive(Context context, Intent intent) { Toast.makeText(SummaryAppMainActivityActivity.this, R.string.sd_removed, 2000).show(); } };</span>

 

         第四个是全屏的设置：写一个简单的方法中；

[java] view plain copy print ?

 <span style="font-size:16px;color:#000000;"> //set the activity is fullScreen
    private void setFullScreen() {
        misFullscreen = !misFullscreen;
        if (misFullscreen) {
            getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                                 WindowManager.LayoutParams.FLAG_FULLSCREEN);
        } else {
            getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
        }
    }</span>
<span style="color:#ff6600;"><strong><span style="font-size:18px;">今天先整理这么少吧，抽空把知识串联一下！呵呵，睡觉了，下次见！
今天参加移动语音开发者大会，见到了柳传志和李开复雷军没有到场，有点遗憾。呵呵，有点收获，听了他们现场的访谈！
</span>
</strong></span>

判断网络是否可用

在Android手机中判断是否联网可以通过 ConnectivityManager 类的isAvailable()方法判断，首先获取网络通讯类的实例

 

ConnectivityManager cwjManager=(ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE); 
  NetworkInfo info = cwjManager.getActiveNetworkInfo();
  if (info != null && info.isAvailable()){

       //do something
  }

 

来返回是否有效，如果为True则表示当前Android手机已经联网，可能是WiFi或GPRS、HSDPA等等，具体的可以通过ConnectivityManager 类的getActiveNetworkInfo() 方法判断详细的接入方式，需要注意的是有关调用需要加入网络访问权限