VB.Net JSON從URL到文本框我如何處理錯誤？

我的JSON字符串返回VB.Net JSON從URL到文本框我如何處理錯誤？

{ 

"name": "username", 
"place": { 
    "name": "placename", 
}

我的代碼目前

Dim request As HttpWebRequest 
    Dim response As HttpWebResponse = Nothing 
    Dim reader As StreamReader 

    Try 

     request = DirectCast(WebRequest.Create("http://my-json.com/json"), HttpWebRequest) 

     response = DirectCast(request.GetResponse(), HttpWebResponse) 
     reader = New StreamReader(response.GetResponseStream()) 

     Dim rawresp As String 
     rawresp = reader.ReadToEnd() 

     Dim jResults As JObject = JObject.Parse(rawresp) 
     usernameTextbox.text = jResults("name").ToString() 
     placenameTextbox.text = jResults("place")("name").ToString() 

    Catch ex As Exception 
     MsgBox(ex.ToString) 
    Finally 
     If Not response Is Nothing Then response.Close() 

    End Try

但是，當我得到一個錯誤，如404我得到一個異常

system.net.webexception: The server returned an error (404) Not Found.

這種情況發生在該行

response = DirectCast(request.GetResponse(), HttpWebResponse)

請你能告訴我關於我如何處理此錯誤並輸出一個消息，一個消息

感謝

來源

2014-02-22 ids

你正在使用'Try/Catch'塊，如果'try'塊內出現異常，它應該到'catch'塊並顯示消息框。情況並非如此嗎？ – har07

在我重寫它的代碼中有一些奇怪的東西，它看起來很好：S – ids

看來我不得不改變

Catch ex As Exception 
    MsgBox(ex.ToString) 
Finally

要

Catch ex As System.Net.WebException 
     MsgBox(ex.ToString) 
Finally

來源

2014-02-28 19:13:40 ids

VB.Net JSON從URL到文本框我如何處理錯誤？

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