Android中判断网络连接是否可用

一、判断网络连接是否可用

public static boolean isNetworkAvailable(Context context) {
		ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
		if (cm == null) {
		} else {
			// 如果仅仅是用来判断网络连接　　　　　　
			// 则可以使用 cm.getActiveNetworkInfo().isAvailable();
			NetworkInfo[] info = cm.getAllNetworkInfo();
			if (info != null) {
				for (int i = 0; i < info.length; i++) {
					if (info[i].getState() == NetworkInfo.State.CONNECTED) {
						return true;
					}
				}
			}
		}
		return false;
	}

下面的不仅可以判断，如果没有开启网络的话，就进入到网络开启那个界面，具体代码如下：

protected boolean CheckNetwork() {
		// TODO Auto-generated method stub
		boolean flag = false;
		ConnectivityManager cwjManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
		if (cwjManager.getActiveNetworkInfo() != null)
			flag = cwjManager.getActiveNetworkInfo().isAvailable();
		if (!flag) {
			Builder b = new AlertDialog.Builder(this).setTitle("没有可用的网络").setMessage("请开启GPRS或WIFI网路连接");
			b.setPositiveButton("确定", new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface dialog, int which) {
					// TODO Auto-generated method stub
					Intent mIntent = new Intent("/");
					ComponentName comp = new ComponentName("com.android.settings", "com.android.settings.WirelessSettings");
					mIntent.setComponent(comp);
					mIntent.setAction("android.intent.action.VIEW");
					startActivity(mIntent);
				}
			}).setNegativeButton("取消", new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface dialog, int which) {
					// TODO Auto-generated method stub dialog.cancel();
				}
			}).create();
			b.show();
		}
		return flag;
	}

用的时候可以这样用：
if(!CheckNetwork()) return;

二、判断GPS是否打开

  public static boolean isGpsEnabled(Context context) {   
        LocationManager lm = ((LocationManager) context   
                .getSystemService(Context.LOCATION_SERVICE));   
        List<String> accessibleProviders = lm.getProviders(true);   
        return accessibleProviders != null && accessibleProviders.size() > 0;   
    } 

三、判断WIFI是否打开

 public static boolean isWifiEnabled(Context context) {   
        ConnectivityManager mgrConn = (ConnectivityManager) context   
                .getSystemService(Context.CONNECTIVITY_SERVICE);   
        TelephonyManager mgrTel = (TelephonyManager) context   
                .getSystemService(Context.TELEPHONY_SERVICE);   
        return ((mgrConn.getActiveNetworkInfo() != null && mgrConn   
                .getActiveNetworkInfo().getState() == NetworkInfo.State.CONNECTED) || mgrTel   
                .getNetworkType() == TelephonyManager.NETWORK_TYPE_UMTS);   
    } 

四、判断是否是3G网络

    public static boolean is3rd(Context context) {   
        ConnectivityManager cm = (ConnectivityManager) context   
                .getSystemService(Context.CONNECTIVITY_SERVICE);   
        NetworkInfo networkINfo = cm.getActiveNetworkInfo();   
        if (networkINfo != null   
                && networkINfo.getType() == ConnectivityManager.TYPE_MOBILE) {   
            return true;   
        }   
        return false;   
    }  

五、判断是wifi还是3g网络,用户的体现性在这里了，wifi就可以建议下载或者在线播放。

  public static boolean isWifi(Context context) {   
            ConnectivityManager cm = (ConnectivityManager) context   
                    .getSystemService(Context.CONNECTIVITY_SERVICE);   
            NetworkInfo networkINfo = cm.getActiveNetworkInfo();   
            if (networkINfo != null   
                    && networkINfo.getType() == ConnectivityManager.TYPE_WIFI) {   
                return true;   
            }   
            return false;   
        }