如何從連接類文件調用connectivityCheck方法? [Android]產品如何從連接類文件調用connectivityCheck方法? [Android]
例如,代碼@連通類文件
public class ConnectivityMgr {
/*
*@return boolean return true if the application can access the internet
*/
public static boolean isNetworkAvailable(Context context) {
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) {
return true;
}
}
}
}
return false;
}
}
我有什麼做的,從類調用此方法,例如,如果它是一個final.last叫包下。測試
我一定要導入的類文件,並聲明或類似的東西,我嘗試使用
if (isNetworkAvailable(getApplicationContext()) == true) {}
,它給了我一個NullPointerException
。是「getApplicationContext()」還是其他的錯誤用法?我嘗試導入,聲明..,改變this.getApplicationContext()/ this/getBaseContext(),它仍然不起作用。
還是需要一個「意圖」?
我做了什麼:
import final.last.test.ConnectivityMgr;
ConnectivityMgr cm;
try {
if (cm.isNetworkAvailable(getApplicationContext())
{ //display yes }
} Catch as (Exception e)
{ Toast.makeText(getApplicationContext(), "Error with connectivity : " + e.getCause() + " , " + e.toString() , Toast.LENGTH_LONG).show();
// Log.d("Error With Connectivity : ","Failed to do something due to : " + e.getMessage());
- >日誌之前從未露面,這就是爲什麼我用麪包來代替。
- >吐司顯示「錯誤與連通性:空,java.lang中,NullPointerException異常 -
顯示調用代碼 – 2012-04-23 04:48:02
ConnectivityMgr.isNetworkAvailable(getApplicationContext( ))和imprt「ConnectivityMgr包」.ConnectivityMgr.Show logcat輸出,如果你仍然有錯誤。 – 2012-04-23 04:56:55
我所做的是... import final.last.test.ConnectivityMgr; ConnectivityMgr cm; 嘗試 { 如果(cm.isNetworkAvailable(getApplicationContext()){ // 顯示是 } } 捕捉儘可能(例外五) \t \t { \t \t \t \t \t \t \t \t \t吐司。「連接錯誤:」+ e.getCause()+「,」+ e.toString(),Toast.LENGTH_LONG).show(); \t \t \t // Log.d(「連接錯誤」,「無法執行某些操作,因爲:」+ e.getMessage()); \t - >日誌從來沒有爲我工作。 (if)(cf.isNetworkAvailable(getApplicationContext());} Toast shows「null,java.lang,NullPointerException – JimmyPW93 2012-04-23 06:59:41