Question

如何检查我的应用是否已连接到互联网？

我找到了这篇文章，但似乎你只能检查连接是否可用。 Detect whether there is an Internet connection available on Android

那个帖子确实有正确的答案，我离我的wifi太远了，总是不及测试。问题解决了。

我希望能够检查这样的事情：

if(!isConnectedToInternet())
{
     Toast.makeText(getApplicationContext(), "Please connect to the internet.", 
     Toast.LENGTH_LONG).show();
}

Answer 1

尝试像这样检查：

private boolean isConnectedToInternet() {
    ConnectivityManager connectivityManager 
          = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
    return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}

在这里查看：

if(!isConnectedToInternet())
{
     Toast.makeText(getApplicationContext(), "Please connect to the internet.", 
     Toast.LENGTH_LONG).show();
}

Answer 2

检查此代码对我来说没问题

public boolean isConnectingToInternet() {
    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;
}

像这样检查

boolean isInternetPresent = cd.isConnectingToInternet();
    if (isInternetPresent) {


    } else {

        Toast.makeText(getApplicationContext(),
                getResources().getString(R.string.internet_error),
                Toast.LENGTH_LONG).show();
    }

Answer 3

answer from the link you attached实际上与您要实现的目标几乎相同。你只需修改几行：

private boolean isConnectedToInternet() {
    ConnectivityManager connectivityManager 
          = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetwork= connectivityManager.getActiveNetworkInfo();
    return  activeNetwork != null && activeNetwork.isConnectedOrConnecting();
}

您可以查看Android中的documentation & guides

Answer 4

您需要检查是否存在已建立的连接

private boolean isConnected() {
ConnectivityManager cm 
      = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = cm.getActiveNetworkInfo();
return activeNetworkInfo != null && activeNetworkInfo.isConnected() && cm.requestRouteToHost(activeNetworkInfo.getType(), yourHostAddress);
}

然后检查是否有到您想要的主机的路由（您可以使用Google进行测试）。检查http://developer.android.com/reference/android/net/ConnectivityManager.html#requestRouteToHost(int，int）

希望它有所帮助。

检查应用是否已连接到互联网

4 个答案: