Question

我收到了这一行的消息，我使用了本地变量＆＃34; name＆＃34;，这是没有设置的。

string firstname = name;

但是我在这一行设置了变量名

name = String.Format("{0} {1}", (string)result["first_name"], (string)result["last_name"]);

我的错误在哪里？我如何设置从名称到名字的值？

private void LoadUserInfo()
{
    string name;
    var fb = new FacebookClient(App.AccessToken);

    fb.GetCompleted += (o, e) =>
    {
        name = String.Format("{0} {1}", (string)result["first_name"], (string)result["last_name"]);
    });

    string firstname = name;

    fb.GetTaskAsync("me");
}

public void LoadUserInfo()
 {
     using (FacebookDataContext db = new FacebookDataContext(DBConnectionstring))
     {
         FacebookClient fb = new FacebookClient(App.AccessToken);
         fb.GetCompleted += (o, e) =>
         {
             var result = (IDictionary<string, object>)e.GetResultData();
             var FBName = String.Format("{0} {1}", (string)result["first_name"], (string)result["last_name"]);
             db._fbcontacts.InsertOnSubmit(new FacebookContactsList { Name = FBName }); 
             db.SubmitChanges();
         };
         fb.GetTaskAsync("me");
     }
 }

Answer 1

以下行位于GetCompleted事件的事件处理程序块中。因此，它将在事件发生时执行，该事件发生在fb.GetTaskAsync("me")调用并完成之后：

name = String.Format("{0} {1}", .......);

这意味着，在您尝试使用name变量的那一刻，它尚未设置：

string firstname = name;

我对firstname稍后您将采取的操作一无所知..事情是，您需要在设置 firstname之后设置name 例如，在同一个事件处理程序块中：

fb.GetCompleted += (o, e) => { name = String.Format("{0} {1}", (string)result["first_name"], (string)result["last_name"]); string firstname = name; .... });

更新：

FacebookClient fb = new FacebookClient(App.AccessToken); fb.GetCompleted += (o, e) => { var result = (IDictionary<string, object>)e.GetResultData(); var FBName = String.Format("{0} {1}", (string)result["first_name"], (string)result["last_name"]); using (FacebookDataContext db = new FacebookDataContext(DBConnectionstring)) { db._fbcontacts.InsertOnSubmit(new FacebookContactsList { Name = FBName }); db.SubmitChanges(); } }; fb.GetTaskAsync("me");

facebook-sdk-net中的变量问题

1 个答案: