单例类抛出名称不存在，错误 [英] singleton class throwing name doesn't existing, error
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问题描述
嗨我正在尝试使用单例类的xmpp连接，但是一个方法和一个变量（isxmppsuccess）显示错误。我的文本框也会抛出错误！
如何在下一页中维护连接？
i是单身人士的新手
下面提到的
是我的完整代码，第二个是错误行：
我的完整代码：
使用系统;
使用 System.Collections.Generic;
使用 System.Linq;
使用 System.Net;
使用 System.Windows;
使用 System.Windows.Controls;
使用 System.Windows.Navigation;
使用 Microsoft.Phone.Controls;
使用 Microsoft.Phone.Shell;
使用 WP8Xmpp.Resources;
使用 System.Net.XMPP;
使用 System.Threading;
命名空间 WP8Xmpp
{
public partial class MainPage：PhoneApplicationPage
{
public MainPage（）
{
InitializeComponent（）;
}
private static XMPPClient ObjXmppClient;
public class singleton
{
private static 单例实例;
private static XMPPConnection ObjXmppCon;
private 布尔 IsXmppSuccess {获得; set ; }
public 字符串用户名{获得; set ; }
public 字符串密码{获得; set ; }
private readonly String Server = taurus;
private readonly 字符串 ServerIPAddress = 127.0.0.1:9090; // 127.0.0.1:9090 /
私有 singleton（）
{
}
public static singleton GetInstance（）
{
if （ instance == null ）
{
instance = new singleton （）;
}
return instance;
}
public static void IsXmppValid（ string UserName， string PassWord）
{
ObjXmppClient = new XMPPClient（）;
ObjXmppClient.JID = UserName + @ + instance.Server;
ObjXmppClient.Password = PassWord;
ObjXmppClient.Server = instance.ServerIPAddress; // 模拟器的用户服务器和设备的IP地址。
ObjXmppClient.AutoReconnect = 真;
ObjXmppClient.RetrieveRoster = true ;
ObjXmppClient.PresenceStatus = new PresenceStatus（）{PresenceType = PresenceType.available，IsOnline = true };
ObjXmppClient.AutoAcceptPresenceSubscribe = true ;
ObjXmppClient.AttemptReconnectOnBadPing = true ;
ObjXmppCon = new XMPPConnection（ObjXmppClient）;
ObjXmppCon.Connect（）;
ObjXmppClient.Connect（）;
// 初始化xmpp连接
ObjXmppCon.OnAsyncConnectFinished + = instance.ObjXmppCon_OnAsyncConnectFinished ;
ObjXmppClient.OnStateChanged + = new EventHandler（instance.XMPPClient_OnStateChanged）;
Thread.Sleep（ 2000 ）;
}
public void ObjXmppCon_OnAsyncConnectFinished（xmedianet.socketserver.SocketClient客户端， bool bSuccess， string strErrors）
{
IsXmppSuccess = client.Connected;
}
public void XMPPClient_OnStateChanged（ object sender，EventArgs e） // 错误
{
开关（ObjXmppClient.XMPPState）
{
case XMPPState.Ready：
if （IsXmppSucces） // 错误
{
此 .Dispatcher.BeginInvoke （（）= >
{
// CloseOverLay（）;
// MessageBox.Show（成功登录）;
NavigationService .Navigate（（ new Uri（ / Output.xaml ？key = success，UriKind.Relative）））; // 错误
// return;
}）;
}
其他
{
此 .Dispatcher.BeginInvoke（（）= > // 错误
{
MessageBox.Show（ 检查服务器名称/ IpAddress ）;
return ;
}）;
}
break ;
case XMPPState.AuthenticationFailed： this .Dispatcher.BeginInvoke（（）= > // 错误
{
MessageBox.Show（ 输入有效的用户名和密码）;
return ;
}）; break ;
}
}
private void btnLogin_Click（ object sender，RoutedEventArgs e） // 错误
{
if （ txtUserName.Text.Trim（）== string .Empty） // 错误
{
MessageBox.Show（ 输入用户名< /跨度>）;
return ;
}
if （txtPassword.Password.Trim（）== string 。空）
{
MessageBox.Show（ 输入密码）;
return ;
}
UserName = txtUserName.Text.Trim（）;
PassWord = txtPassword.Password.Trim（）;
IsXmppValid（）;
}
}
}
}
2>我在这些方法中遇到错误：
public void XMPPClient_OnStateChanged（ object sender，EventArgs e） // 错误
{
开关（ObjXmppClient.XMPPState）
{
case XMPPState.Ready：
if （IsXmppSucces） // 不存在错误
{
this .Dispatcher.BeginInvoke（（）= > // < pre> Dispatcher - 不包含定义错误
{
// CloseOverLay（）;
// MessageBox.Show（& quot;成功登录& quot;）;
NavigationService.Navigate （（ new Uri（& quot; /Output.xaml？key = success& quot;，UriKind.Relative）））; // 错误
// 返回;
}）;
}
其他
{
此 .Dispatcher.BeginInvoke（（）=& gt; // 错误
{
MessageBox.Show（& quot; Check server name / IpAddress& quot;）;
return ;
}）;
}
break ;
case XMPPState.AuthenticationFailed： this .Dispatcher.BeginInvoke（（）= & gt; // 错误
{
MessageBox.Show（& 输入有效的用户名和密码& quot;）;
return ;
}）; break ;
}
}
< / pre >
2.
private void btnLogin_Click（object sender，RoutedEventArgs e）//错误
{
if（txtUserName.Text.Trim（）== string.Empty）//无法访问非静态成员
{
MessageBox.Show（输入用户名）;
返回;
}
if（txtPassword.Password.Trim（） == string.Empty）
{
MessageBox.Show（输入密码）;
返回;
}
UserName = txtUserName.Text.Trim（）;
PassWord = txtP assword.Password.Trim（）;
IsXmppValid（）; // 0参数错误
}
解决方案
所以有几件事。你的单身人士不是线程安全的，并且可以按照现在的方式进行比赛。关于它的文章非常好：
http://csharpindepth.com/Articles/General/Singleton.aspx
最简单修复是将实例属性更改为：
private 静态懒惰< singleton> instance = new Lazy< singleton>（（）= > new singleton（））;
public static singleton GetInstance { get { return instance.Value;现在，您所看到的问题与将事件传递给调用私有变量的其他对象（IsXmppSuccess）有关。现在，您需要看到的问题是什么？$ / p $ p>
。将该变量公之于众。
Hi iam trying an xmpp connection using singleton class,but a methode and a variable(isxmppsuccess) showing errors.My textboxes also throwing error!
how i can maintain the connection in next page also?
i am new to the singleton
below mentioned is my full code and second one is error lines:
my full code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Navigation;
using Microsoft.Phone.Controls;
using Microsoft.Phone.Shell;
using WP8Xmpp.Resources;
using System.Net.XMPP;
using System.Threading;
namespace WP8Xmpp
{
public partial class MainPage : PhoneApplicationPage
{
public MainPage()
{
InitializeComponent();
}
private static XMPPClient ObjXmppClient;
public class singleton
{
private static singleton instance;
private static XMPPConnection ObjXmppCon;
private Boolean IsXmppSuccess { get; set; }
public String UserName { get; set; }
public String PassWord { get; set; }
private readonly String Server = "taurus";
private readonly String ServerIPAddress = "127.0.0.1:9090";//127.0.0.1:9090/
private singleton()
{
}
public static singleton GetInstance()
{
if (instance == null)
{
instance = new singleton();
}
return instance;
}
public static void IsXmppValid(string UserName, string PassWord)
{
ObjXmppClient = new XMPPClient();
ObjXmppClient.JID = UserName + "@" + instance.Server;
ObjXmppClient.Password = PassWord;
ObjXmppClient.Server = instance.ServerIPAddress; //user server for emulator and ip address for device.
ObjXmppClient.AutoReconnect = true;
ObjXmppClient.RetrieveRoster = true;
ObjXmppClient.PresenceStatus = new PresenceStatus() { PresenceType = PresenceType.available, IsOnline = true };
ObjXmppClient.AutoAcceptPresenceSubscribe = true;
ObjXmppClient.AttemptReconnectOnBadPing = true;
ObjXmppCon = new XMPPConnection(ObjXmppClient);
ObjXmppCon.Connect();
ObjXmppClient.Connect();
//initializing the xmpp connection
ObjXmppCon.OnAsyncConnectFinished +=instance.ObjXmppCon_OnAsyncConnectFinished;
ObjXmppClient.OnStateChanged += new EventHandler(instance.XMPPClient_OnStateChanged);
Thread.Sleep(2000);
}
public void ObjXmppCon_OnAsyncConnectFinished(xmedianet.socketserver.SocketClient client, bool bSuccess, string strErrors)
{
IsXmppSuccess = client.Connected;
}
public void XMPPClient_OnStateChanged(object sender, EventArgs e)//error
{
switch (ObjXmppClient.XMPPState)
{
case XMPPState.Ready:
if (IsXmppSucces)//error
{
this.Dispatcher.BeginInvoke(() =>
{
//CloseOverLay();
//MessageBox.Show("Successfully logged in");
NavigationService.Navigate((new Uri("/Output.xaml?key=success", UriKind.Relative)));//error
//return;
});
}
else
{
this.Dispatcher.BeginInvoke(() =>//error
{
MessageBox.Show("Check server name/IpAddress");
return;
});
}
break;
case XMPPState.AuthenticationFailed: this.Dispatcher.BeginInvoke(() =>//error
{
MessageBox.Show("Enter valid username and password");
return;
}); break;
}
}
private void btnLogin_Click(object sender, RoutedEventArgs e)//error
{
if (txtUserName.Text.Trim() == string.Empty)//error
{
MessageBox.Show("Enter Username");
return;
}
if (txtPassword.Password.Trim() == string.Empty)
{
MessageBox.Show("Enter Password");
return;
}
UserName = txtUserName.Text.Trim();
PassWord = txtPassword.Password.Trim();
IsXmppValid();
}
}
}
}
2> i am getting error in these methodes:
public void XMPPClient_OnStateChanged(object sender, EventArgs e)//error
{
switch (ObjXmppClient.XMPPState)
{
case XMPPState.Ready:
if (IsXmppSucces) // doesnot exist error
{
this.Dispatcher.BeginInvoke(() =>//<pre>Dispatcher-doesnot contain the definition error
{
//CloseOverLay();
//MessageBox.Show("Successfully logged in");
NavigationService.Navigate((new Uri("/Output.xaml?key=success", UriKind.Relative)));//error
//return;
});
}
else
{
this.Dispatcher.BeginInvoke(() =>//error
{
MessageBox.Show("Check server name/IpAddress");
return;
});
}
break;
case XMPPState.AuthenticationFailed: this.Dispatcher.BeginInvoke(() =>//error
{
MessageBox.Show("Enter valid username and password");
return;
}); break;
}
}
</pre>
2.
private void btnLogin_Click(object sender, RoutedEventArgs e)//error
{
if (txtUserName.Text.Trim() == string.Empty)//cannot access non static member
{
MessageBox.Show("Enter Username");
return;
}
if (txtPassword.Password.Trim() == string.Empty)
{
MessageBox.Show("Enter Password");
return;
}
UserName = txtUserName.Text.Trim();
PassWord = txtPassword.Password.Trim();
IsXmppValid();//0 arguments error
}
解决方案
So a couple of things. Your singleton isn't thread safe, and could race with the way it's implemented now. There is an excellent article about it at:
http://csharpindepth.com/Articles/General/Singleton.aspx
The easiest fix is to change the instance property to:
private static Lazy<singleton> instance = new Lazy<singleton>(() => new singleton()); public static singleton GetInstance { get { return instance.Value; } }
Now, the issue that you're seeing is related to passing events to other objects that call a private variable (IsXmppSuccess). Make that variable public.
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