Question

我试图找出这个＆＃34; POST＆＃34;请求，并将代码翻译成vb.net，用于webrequest。将评论我已经知道的内容

var xmlhttp; //Defining the "xmlhttp" variable
    if (window.XMLHttpRequest) {
        xmlhttp = new XMLHttpRequest() 
    } else {
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP")
    }
    xmlhttp.onreadystatechange = function() { //If the xmlhttp is created then do this:
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) { //Don't know
            fired = true; //The function gathered the conditions to start
            var title = '<div id="message_box_title_unavailable">woops!</div>'; //Doesn't matter
            var result; //Variable "result"
            if (xmlhttp.responseText == 'available') { //If the xml file contains "available" on it then do this, else return an error...
                result = 'The name you selected <strong>' + user + 'is available!'
            } else {
                result = 'There was an error processing your request.  Please try again.'
            }
        }
    };
    xmlhttp.open("POST", "Checkusername.php", true); //Didn't I translate this correctly?
    xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); //What am I missing from this line in my vb code?
    xmlhttp.send("name=" + name + "&n=" + Math.random()) //The same...
}

好的 - 我的Vb翻译

Dim req As HttpWebRequest
Dim res As HttpWebResponse
Dim cookies As New CookieContainer()
req = WebRequest.Create("http://blablabla.net/Checkusername.php?name=" & name "&n=" R.Next(0, 20000))
req.Method = "POST"
req.ContentType = "application/xml"
req.Headers.Add("Content-type", "application/x-www-form-urlencoded")
req.CookieContainer = cookies
res = req.GetResponse
Dim webStream As Stream
webStream = res.GetResponseStream
Dim reader As New StreamReader(webStream)
checksource.text = reader.readtoend

这总是给我一个＆＃34;错误＆＃34;而不是所需的结果，这在HTML

中始终是正确的

基本上，我无法翻译第3/5行和最后的第3行。

感谢您的帮助！

Answer 1

当您进行GET时，您在网址中提供参数。当您执行POST时，您在请求中提供它们。另外，如果您不使用cookie对象，也不确定为什么要创建cookie对象。

您不需要：

Dim res As HttpWebResponse
Dim cookies As New CookieContainer()

试试这个：

'Create the post string which contains the params
Dim postString As String = "name=" & name & "&n=" & R.Next(0, 20000)

'Create the request
req = WebRequest.Create("http://blablabla.net/Checkusername.php")
req.Method = "POST"
req.ContentLength = postString.Length
req.ContentType = "application/x-www-form-urlencoded"

'put the POST params in the request
Dim requestWriter As StreamWriter = New StreamWriter(req.GetRequestStream())
requestWriter.Write(postString)
requestWriter.Close()

'submit the request and read the response
Dim responseReader As StreamReader = New StreamReader(req.GetResponse().GetResponseStream())
Dim responseData As String = responseReader.ReadToEnd()

'close everything
responseReader.Close()
req.GetResponse().Close()

responseData 将包含您的回复字符串

您还可以使用Try / Catch将其包围，以检查是否存在任何异常...网络连接不良，网址错误，无响应等.html中的xmlhttp.readyState == 4 && xmlhttp.status == 200表示request finished和{{ 1}}

Javascript转VB.Net [FEW LINES]

1 个答案: