Question

我的活动检查互联网连接并显示ProgresDialog（如果有连接）。现在，如果显示ProgressdlDialog并且互联网连接不可用，那么可怜的ProgressDialog会一直加载到enternity。所以，我想检测progressdialog的状态;然后显示AlertDialog，如果它的加载和互联网连接不可用。

Answer 1

您可以使用CONNECTIVITY_CHANGE Receiver来了解连接何时更改，而不是使用方法来使用以下代码获取连接的实际状态：

ConnectivityManager cm =
        (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);

NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
boolean isConnected = activeNetwork != null &&
                      activeNetwork.isConnectedOrConnecting();

请参阅：http://developer.android.com/intl/pt-br/training/monitoring-device-state/connectivity-monitoring.html

http://viralpatel.net/blogs/android-internet-connection-status-network-change/

Answer 2

检测ProgressDialog

let arr0:[Int?]? = [1,2,3]

if let r = arr0 where r.dynamicType == [Int].self {
    print(r, r.dynamicType)
} else {
    print("not [Int]")
}
// prints 
// not [Int]

// but
func foo()->[Int] {
    let arr0:[Int?]? = [1,2,3]
    if let r = arr0 where r.dynamicType == [Int].self {
        print(r, r.dynamicType)
        // !!!!! ERROR !!!!!
        // next line doesn't compile wihout flatMap !!!!
        //
        // error: cannot convert return expression of type '[Int?]' to return type '[Int]'
        //
        // even though that it is clear from the where clause that r type must be [Int]
        return r.flatMap{ $0 }
    } else {
        print("arr0 is not [Int]")
        return []
    }
}
foo() // [] and prints: arr0 is not [Int]

如何检测ProgressDialog

2 个答案: