Microsoft.Practices.ServiceLocation.ActivationException

Question

我正在尝试使用ServiceLocator创建一个实例

/// <summary>
/// Gets the MediaPlayer property.
/// </summary>
[SuppressMessage("Microsoft.Performance", "CA1822:MarkMembersAsStatic", Justification = "This non-static member is needed for data binding purposes.")]
public MediaPlayerViewModel MediaPlayer
{
    get
    {
        try
        {
            return ServiceLocator.Current.GetInstance<MediaPlayerViewModel>();
        }
        catch (Exception e)
        {
            System.Console.WriteLine(e.ToString());
            return null;
        }
    }
}

但我得到了以下的解释：

用户代码HResult=-2146233088 Microsoft.Practices.ServiceLocation.ActivationException在试图获取MediaPlayerViewModel类型的实例时发生了“键”错误。 在Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance(Type serviceType，字符串键)在c:\Projects\CommonServiceLocator\main\Microsoft.Practices.ServiceLocation\ServiceLocatorImplBase.cs:line 53 at Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstanceTService in c:\Projects\CommonServiceLocator\main\Microsoft.Practices.ServiceLocation\ServiceLocatorImplBase.cs:line 90 at Verint.PI2.MediaPlayer.UI.ViewModel.ViewModelLocator.get_MediaPlayer() in c:\Users\ekreiczer\Documents\Visual 2012\Projects\player\Verint.PI2.MediaPlayer.UI\ViewModel\ViewModelLocator.cs:第73行InnerException: InnerException HResult=-2146233088 Message=Resolution的依赖项失败，type = "Verint.PI2.MediaPlayer.UI.ViewModel.MediaPlayerViewModel"，name = "(none)“。当:进行解析时发生异常。例外是: Verint.PI2.MediaPlayer.UI.Services.IDialogService，-当前类型，InvalidOperationException是一个接口，不能构造。您缺少类型映射吗？

我不知道怎么打地图，有人能帮忙吗？

Answer 1

MediaPlayerViewModel很可能依赖于Verint.PI2.MediaPlayer.UI.Services.IDialogService的实现。

查看构造函数和MediaPlayerViewModel的属性来验证这一点。

您忘记将Verint.PI2.MediaPlayer.UI.Services.IDialogService映射到引导程序中的实现。