判断当前网络是否可用和调用系统设置wifi界面

需要用到的权限

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET"/>

//判断当前网络是否可用
	public boolean note_Intent(Context context) {  
	    ConnectivityManager con = (ConnectivityManager) context  
	        .getSystemService(Context.CONNECTIVITY_SERVICE);  
	    NetworkInfo networkinfo = con.getActiveNetworkInfo();  
	    if (networkinfo == null || !networkinfo.isAvailable()) {  
	    // 当前网络不可用   
	        Toast.makeText(context.getApplicationContext(), "当前网络不可用",  
	        Toast.LENGTH_SHORT).show();  
	        return false;  
	    }  
	    boolean wifi = con.getNetworkInfo(ConnectivityManager.TYPE_WIFI)  
	        .isConnectedOrConnecting();  
	    if (!wifi) { // 提示使用wifi   
	        Toast.makeText(context.getApplicationContext(), "建议您使用WIFI以减少流量！",  
	        Toast.LENGTH_SHORT).show();  
	    }  
	    return true;  
	  
	}

跳转到系统设置WIFI界面中

Intent localIntent = new Intent();
		localIntent.setComponent(new ComponentName("com.android.settings",
				"com.android.settings.wifi.WifiPickerActivity"));
		startActivityForResult(localIntent, 100);