ConnectivityStatus.IsOffline 属性

public:
 static property bool IsOffline { bool get(); void set(bool value); };

public static bool IsOffline { get; set; }

static member IsOffline : bool with get, set

Public Shared Property IsOffline As Boolean

属性值

如果应用程序处于脱机模式，则为 true；否则为 false。

示例

以下示例代码演示如何使用此属性根据检查框值更新脱机状态。 在此示例中， CheckedChanged 事件处理程序更新脱机状态。 如果用户将应用程序设置为联机状态，则事件处理程序会尝试重新验证用户。 但是，如果身份验证服务器不可用，事件处理程序会将应用程序返回到脱机状态。

private void workOfflineCheckBox_CheckedChanged(
    object sender, EventArgs e)
{
    ConnectivityStatus.IsOffline = workOfflineCheckBox.Checked;
    if (!ConnectivityStatus.IsOffline)
    {
        try
        {
            // Silently re-validate the user.
            ((ClientFormsIdentity)
                System.Threading.Thread.CurrentPrincipal.Identity)
                .RevalidateUser();

            // If any settings have been changed locally, save the new
            // new values to the Web settings service.
            SaveSettings();

            // If any settings have not been changed locally, check 
            // the Web settings service for updates. 
            Properties.Settings.Default.Reload();
        }
        catch (System.Net.WebException)
        {
            MessageBox.Show(
                "Unable to access the authentication service. " +
                Environment.NewLine + "Staying in offline mode.",
                "Warning", MessageBoxButtons.OK, 
                MessageBoxIcon.Warning);
            workOfflineCheckBox.Checked = true;
        }
    }
}

Private Sub workOfflineCheckBox_CheckedChanged( _
    ByVal sender As Object, ByVal e As EventArgs) _
    Handles workOfflineCheckBox.CheckedChanged

    ConnectivityStatus.IsOffline = workOfflineCheckBox.Checked
    If Not ConnectivityStatus.IsOffline Then

        Try

            ' Silently re-validate the user.
            CType(System.Threading.Thread.CurrentPrincipal.Identity,  _
                ClientFormsIdentity).RevalidateUser()

            ' If any settings have been changed locally, save the new
            ' new values to the Web settings service.
            SaveSettings()

            ' If any settings have not been changed locally, check 
            ' the Web settings service for updates. 
            My.Settings.Reload()

        Catch ex As System.Net.WebException

            MessageBox.Show( _
                "Unable to access the authentication service. " & _
                Environment.NewLine + "Staying in offline mode.", _
                "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            workOfflineCheckBox.Checked = True

        End Try

    End If
End Sub

注解

设置 IsOffline 属性时， ConnectivityStatus 类会将值缓存到本地文件系统。 命名空间中的System.Web.ClientServices.Providers客户端服务提供商检查此值，以确定是否使用脱机数据缓存，而不是尝试访问关联的 Microsoft Ajax 身份验证、角色和配置文件服务。

适用于

另请参阅

• RevalidateUser()
• 客户端应用程序服务