LuaSocket测试互联网连接的存在

Question

我正在尝试使用LuaSocket库测试Corona SDK中是否存在互联网连接.

我找到了这个解决方案

function test()           
    local connection = socket.tcp()
    connection:settimeout(1000)
    local result = connection:connect("www.google.com", 80)
    connection:close()
    if (result) then return true end
    return false
end

但它有一个问题:如果连接错误/不稳定,程序将被阻塞,直到套接字运行(持续不同的秒数).

所以我试着这样:

    connection:settimeout(1000, 't')

但它非常不准确(在网络滞后的情况下会返回false).有一个更好的方法？

也许让套接字没有阻塞？

更新2: 我尝试了这段代码,但我真的不明白它是否有意义......

local socket = require("socket") 
function test(callback, timeout)
    if timeout == nil then timeout = 1000 end
    local connection = socket.tcp()
    connection:settimeout(0)
    connection:connect("www.google.com", 80)
    local t
    t = timer.performWithDelay( 10, function()
        local r = socket.select({connection}, nil, 0)
        if r[1] or timeout == 0 then
            connection:close()
            timer.cancel( t )
            callback(timeout > 0)
        end
        timeout = timeout - 10
    end , 0)
end

它始终返回"无连接"

Answer 1

最后,我找到了一种让它适用于所有设备的方法.谢谢hades2510:

---------------------------------------
-- Test connection to the internet
---------------------------------------
local socket = require("socket")

local connection = {}
local function manual_test(callback, timeout)
    if timeout == nil then timeout = 1000 end
    local connection = assert(socket.tcp())
    connection:settimeout(0)
    local result = connection:connect("www.google.com", 80)
    local t
    t = timer.performWithDelay( 10, function()
        local r, w, e = socket.select(nil, {connection}, 0)
        if w[1] or timeout == 0 then
            connection:close()
            timer.cancel( t )
            callback(timeout > 0)
        end
        timeout = timeout - 10
    end , 0)
end
local isReachable = nil
function connection.test(callback)
    if network.canDetectNetworkStatusChanges then
        if isReachable == nil then
            local function networkListener(event)
                isReachable = event.isReachable
                callback(isReachable)
            end
            network.setStatusListener( "www.google.com", networkListener )
        else
            callback(isReachable)
        end
    else
        manual_test(callback)
    end
end
return connection

https://gist.github.com/ProGM/9786014